feat: add frontend case list, detail, and creation pages (Phase 1F)

- Case list page (/cases) with search, status/type filters, status badges
- Case creation page (/cases/new) with reusable CaseForm component
- Case detail page (/cases/[id]) with tabs: Timeline, Deadlines, Documents, Parties
- CaseTimeline component for chronological case_events display
- PartyList component with inline party CRUD (add/delete)
- Updated sidebar navigation to route to /cases

.claude/agents/coder.md

@@ -0,0 +1,14 @@
+# Coder Agent
+
+Implementation-focused agent for writing and refactoring code.
+
+## Instructions
+
+- Follow existing patterns in the codebase
+- Write minimal, focused code
+- Run tests after changes
+- Commit incrementally with descriptive messages
+
+## Tools
+
+All tools available.

.claude/agents/researcher.md

@@ -0,0 +1,14 @@
+# Researcher Agent
+
+Exploration and information gathering agent.
+
+## Instructions
+
+- Search broadly, then narrow down
+- Document findings in structured format
+- Cite sources and file paths
+- Summarize key insights, don't dump raw data
+
+## Tools
+
+Read-only tools preferred. Use Bash only for non-destructive commands.

.claude/agents/reviewer.md

@@ -0,0 +1,14 @@
+# Reviewer Agent
+
+Code review agent for checking quality and correctness.
+
+## Instructions
+
+- Check for bugs, security issues, and style violations
+- Verify test coverage for changes
+- Suggest improvements concisely
+- Focus on correctness over style preferences
+
+## Tools
+
+Read-only tools. No file modifications.

.claude/skills/mai-clone

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-clone

.claude/skills/mai-coder

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-coder

.claude/skills/mai-commit

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-commit

.claude/skills/mai-consultant

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-consultant

.claude/skills/mai-daily

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-daily

.claude/skills/mai-debrief

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-debrief

.claude/skills/mai-enemy

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-enemy

.claude/skills/mai-excalidraw

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-excalidraw

.claude/skills/mai-fixer

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-fixer

.claude/skills/mai-gitster

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-gitster

.claude/skills/mai-head

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-head

.claude/skills/mai-init

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-init

.claude/skills/mai-inventor

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-inventor

.claude/skills/mai-lead

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-lead

.claude/skills/mai-maister

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-maister

.claude/skills/mai-member

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-member

.claude/skills/mai-researcher

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-researcher

.claude/skills/mai-think

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-think

.claude/skills/mai-web

@@ -0,0 +1 @@
+/home/m/.mai/skills/mai-web

.env.example

@@ -7,6 +7,7 @@ PORT=8080
 # Supabase (required for database access)
 SUPABASE_URL=
 SUPABASE_ANON_KEY=
+SUPABASE_SERVICE_KEY=
 
 # Claude API (required for AI features)
 ANTHROPIC_API_KEY=

.gitignore

@@ -45,3 +45,4 @@ tmp/
 
 # TypeScript
 *.tsbuildinfo
+.worktrees/

.m/.gitignore

@@ -0,0 +1,4 @@
+workers.json
+spawn.lock
+session.yaml
+config.reference.yaml

.m/config.yaml

@@ -0,0 +1,168 @@
+provider: claude
+providers:
+    claude:
+        api_key: ""
+        model: claude-sonnet-4-20250514
+        base_url: https://api.anthropic.com/v1
+    ollama:
+        host: http://localhost:11434
+        model: llama3.2
+memory:
+    enabled: true
+    backend: ""
+    path: ""
+    url: postgres://mai_memory.your-tenant-id:maiMem6034supa@100.99.98.201:6543/postgres?sslmode=disable
+    group_id: ""
+    cache_ttl: 5m0s
+    auto_load: true
+    embedding_url: ""
+    embedding_model: ""
+gitea:
+    url: https://mgit.msbls.de
+    repo: m/KanzlAI
+    token: ""
+    sync:
+        enabled: false
+        interval: 0s
+        repos: []
+        auto_queue: false
+api:
+    api_key: ""
+    basic_auth:
+        username: ""
+        password: ""
+    public_endpoints:
+        - /api/health
+ui:
+    theme: default
+    show_sidebar: true
+    animation: true
+    persona: true
+    avatar_pack: ""
+worker:
+    names: []
+    name_scheme: role
+    default_level: standard
+    auto_discard: false
+    max_workers: 5
+    persistent: true
+head:
+    name: ingeborg
+    max_loops: 50
+    infinity_mode: false
+capacity:
+    global:
+        max_workers: 5
+        max_heads: 3
+    per_worker:
+        max_tasks_lifetime: 0
+        max_concurrent: 1
+        max_context_tokens: 0
+    per_head:
+        max_workers: 10
+    resources:
+        max_memory_mb: 0
+        max_cpu_percent: 0
+    queue:
+        max_pending: 100
+        stale_task_days: 30
+workforce:
+    timeouts:
+        task_default: 0s
+        task_max: 0s
+        idle_before_warn: 10m0s
+        idle_before_kill: 30m0s
+        quality_check: 2m0s
+    context:
+        max_tokens_per_worker: 0
+        max_tokens_global: 0
+        warn_threshold: 0.8
+        truncate_strategy: oldest
+    delegation:
+        strategy: skill_match
+        preferred_role: coder
+        auto_delegate: false
+        max_depth: 3
+        allowed_roles:
+            - coder
+            - researcher
+            - fixer
+    peppy:
+        enabled: false
+        style: calm
+        interval: 5m0s
+        emoji: false
+        nudges: true
+        nudge_main: false
+        custom_prompt: ""
+        stall_threshold: 0s
+        restart_enabled: false
+        max_shifts: 0
+quality_gates:
+    enabled: true
+    checks: []
+preflight:
+    enabled: false
+    type: ""
+    root: ""
+    checks: []
+guardrails:
+    enabled: false
+    use_defaults: true
+    output:
+        coder_checks: []
+        researcher_checks: []
+        fixer_checks: []
+        custom_checks: {}
+        global_checks: []
+    tools:
+        role_rules: {}
+        deny_patterns: []
+        allow_patterns: []
+    schemas:
+        report_schemas: {}
+        deliverable_schemas: {}
+modes:
+    yolo: false
+    self_improvement: false
+    autonomous: false
+    verbose: false
+    improve_interval: 0s
+    predict_interval: 0s
+layouts:
+    head: ""
+    worker: ""
+    roles: {}
+dog:
+    name: buddy
+supabase:
+    url: ""
+    role_key: ""
+    anon_key: ""
+    schema: mai
+storage:
+    backend: ""
+    postgres:
+        url: ""
+        max_conns: 0
+        min_conns: 0
+        max_conn_lifetime: 0s
+idle:
+    behavior: wait
+    auto_hire: false
+    prompt: ""
+git:
+    worktrees:
+        enabled: true
+        delete_branch: false
+        dir: .worktrees
+phase:
+    enabled: false
+    current: ""
+    allowed_roles: {}
+goal: ""
+skills: {}
+editor: nvim
+log_level: info
+project_detection: true
+tone: professional

.mcp.json

@@ -0,0 +1,22 @@
+{
+  "mcpServers": {
+    "mai": {
+      "type": "http",
+      "url": "http://100.99.98.201:8000/mcp",
+      "headers": {
+        "Authorization": "Basic ${SUPABASE_AUTH}"
+      }
+    },
+    "mai-memory": {
+      "command": "mai",
+      "args": [
+        "mcp",
+        "memory"
+      ],
+      "env": {
+        "MAI_MEMORY_EMBEDDING_MODEL": "nomic-embed-text",
+        "MAI_MEMORY_EMBEDDING_URL": "https://llm.x.msbls.de"
+      }
+    }
+  }
+}

AGENTS.md

@@ -0,0 +1 @@
+.claude/CLAUDE.md

backend/cmd/server/main.go

@@ -22,8 +22,8 @@ func main() {
 	}
 	defer database.Close()
 
-	authMW := auth.NewMiddleware(cfg.SupabaseJWTSecret)
+	authMW := auth.NewMiddleware(cfg.SupabaseJWTSecret, database)
-	handler := router.New(database, authMW)
+	handler := router.New(database, authMW, cfg)
 
 	log.Printf("Starting KanzlAI API server on :%s", cfg.Port)
 	if err := http.ListenAndServe(":"+cfg.Port, handler); err != nil {

backend/go.mod

@@ -3,8 +3,14 @@ module mgit.msbls.de/m/KanzlAI-mGMT
 go 1.25.5
 
 require (
+	github.com/anthropics/anthropic-sdk-go v1.27.1 // indirect
 	github.com/golang-jwt/jwt/v5 v5.3.1 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/jmoiron/sqlx v1.4.0 // indirect
 	github.com/lib/pq v1.12.0 // indirect
+	github.com/tidwall/gjson v1.18.0 // indirect
+	github.com/tidwall/match v1.1.1 // indirect
+	github.com/tidwall/pretty v1.2.1 // indirect
+	github.com/tidwall/sjson v1.2.5 // indirect
+	golang.org/x/sync v0.16.0 // indirect
 )

backend/go.sum

@@ -1,4 +1,6 @@
 filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
+github.com/anthropics/anthropic-sdk-go v1.27.1 h1:7DgMZ2Ng3C2mPzJGHA30NXQTZolcF07mHd0tGaLwfzk=
+github.com/anthropics/anthropic-sdk-go v1.27.1/go.mod h1:qUKmaW+uuPB64iy1l+4kOSvaLqPXnHTTBKH6RVZ7q5Q=
 github.com/go-sql-driver/mysql v1.8.1/go.mod h1:wEBSXgmK//2ZFJyE+qWnIsVGmvmEKlqwuVSjsCm7DZg=
 github.com/golang-jwt/jwt/v5 v5.3.1 h1:kYf81DTWFe7t+1VvL7eS+jKFVWaUnK9cB1qbwn63YCY=
 github.com/golang-jwt/jwt/v5 v5.3.1/go.mod h1:fxCRLWMO43lRc8nhHWY6LGqRcf+1gQWArsqaEUEa5bE=
@@ -10,3 +12,15 @@ github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/lib/pq v1.12.0 h1:mC1zeiNamwKBecjHarAr26c/+d8V5w/u4J0I/yASbJo=
 github.com/lib/pq v1.12.0/go.mod h1:/p+8NSbOcwzAEI7wiMXFlgydTwcgTr3OSKMsD2BitpA=
 github.com/mattn/go-sqlite3 v1.14.22/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
+github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/gjson v1.18.0 h1:FIDeeyB800efLX89e5a8Y0BNH+LOngJyGrIWxG2FKQY=
+github.com/tidwall/gjson v1.18.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
+github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
+github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
+github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/tidwall/sjson v1.2.5 h1:kLy8mja+1c9jlljvWTlSazM7cKDRfJuR/bOJhcY5NcY=
+github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6jwd28=
+golang.org/x/sync v0.16.0 h1:ycBJEhp9p4vXvUZNszeOq0kGTPghopOL8q0fq3vstxw=
+golang.org/x/sync v0.16.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=

backend/internal/auth/middleware.go

@@ -8,14 +8,16 @@ import (
 
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
 )
 
 type Middleware struct {
 	jwtSecret []byte
+	db        *sqlx.DB
 }
 
-func NewMiddleware(jwtSecret string) *Middleware {
+func NewMiddleware(jwtSecret string, db *sqlx.DB) *Middleware {
-	return &Middleware{jwtSecret: []byte(jwtSecret)}
+	return &Middleware{jwtSecret: []byte(jwtSecret), db: db}
 }
 
 func (m *Middleware) RequireAuth(next http.Handler) http.Handler {
@@ -33,6 +35,17 @@ func (m *Middleware) RequireAuth(next http.Handler) http.Handler {
 		}
 
 		ctx := ContextWithUserID(r.Context(), userID)
+
+		// Resolve tenant from user_tenants
+		var tenantID uuid.UUID
+		err = m.db.GetContext(r.Context(), &tenantID,
+			"SELECT tenant_id FROM user_tenants WHERE user_id = $1 LIMIT 1", userID)
+		if err != nil {
+			http.Error(w, "no tenant found for user", http.StatusForbidden)
+			return
+		}
+		ctx = ContextWithTenantID(ctx, tenantID)
+
 		next.ServeHTTP(w, r.WithContext(ctx))
 	})
 }

backend/internal/auth/tenant_resolver.go

@@ -0,0 +1,61 @@
+package auth
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/google/uuid"
+)
+
+// TenantLookup resolves the default tenant for a user.
+// Defined as an interface to avoid circular dependency with services.
+type TenantLookup interface {
+	FirstTenantForUser(ctx context.Context, userID uuid.UUID) (*uuid.UUID, error)
+}
+
+// TenantResolver is middleware that resolves the tenant from X-Tenant-ID header
+// or defaults to the user's first tenant.
+type TenantResolver struct {
+	lookup TenantLookup
+}
+
+func NewTenantResolver(lookup TenantLookup) *TenantResolver {
+	return &TenantResolver{lookup: lookup}
+}
+
+func (tr *TenantResolver) Resolve(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		userID, ok := UserFromContext(r.Context())
+		if !ok {
+			http.Error(w, "unauthorized", http.StatusUnauthorized)
+			return
+		}
+
+		var tenantID uuid.UUID
+
+		if header := r.Header.Get("X-Tenant-ID"); header != "" {
+			parsed, err := uuid.Parse(header)
+			if err != nil {
+				http.Error(w, fmt.Sprintf("invalid X-Tenant-ID: %v", err), http.StatusBadRequest)
+				return
+			}
+			tenantID = parsed
+		} else {
+			// Default to user's first tenant
+			first, err := tr.lookup.FirstTenantForUser(r.Context(), userID)
+			if err != nil {
+				http.Error(w, fmt.Sprintf("resolving tenant: %v", err), http.StatusInternalServerError)
+				return
+			}
+			if first == nil {
+				http.Error(w, "no tenant found for user", http.StatusBadRequest)
+				return
+			}
+			tenantID = *first
+		}
+
+		ctx := ContextWithTenantID(r.Context(), tenantID)
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}

backend/internal/auth/tenant_resolver_test.go

@@ -0,0 +1,124 @@
+package auth
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/google/uuid"
+)
+
+type mockTenantLookup struct {
+	tenantID *uuid.UUID
+	err      error
+}
+
+func (m *mockTenantLookup) FirstTenantForUser(ctx context.Context, userID uuid.UUID) (*uuid.UUID, error) {
+	return m.tenantID, m.err
+}
+
+func TestTenantResolver_FromHeader(t *testing.T) {
+	tenantID := uuid.New()
+	tr := NewTenantResolver(&mockTenantLookup{})
+
+	var gotTenantID uuid.UUID
+	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		id, ok := TenantFromContext(r.Context())
+		if !ok {
+			t.Fatal("tenant ID not in context")
+		}
+		gotTenantID = id
+		w.WriteHeader(http.StatusOK)
+	})
+
+	r := httptest.NewRequest("GET", "/api/cases", nil)
+	r.Header.Set("X-Tenant-ID", tenantID.String())
+	r = r.WithContext(ContextWithUserID(r.Context(), uuid.New()))
+	w := httptest.NewRecorder()
+
+	tr.Resolve(next).ServeHTTP(w, r)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	if gotTenantID != tenantID {
+		t.Errorf("expected tenant %s, got %s", tenantID, gotTenantID)
+	}
+}
+
+func TestTenantResolver_DefaultsToFirst(t *testing.T) {
+	tenantID := uuid.New()
+	tr := NewTenantResolver(&mockTenantLookup{tenantID: &tenantID})
+
+	var gotTenantID uuid.UUID
+	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		id, _ := TenantFromContext(r.Context())
+		gotTenantID = id
+		w.WriteHeader(http.StatusOK)
+	})
+
+	r := httptest.NewRequest("GET", "/api/cases", nil)
+	r = r.WithContext(ContextWithUserID(r.Context(), uuid.New()))
+	w := httptest.NewRecorder()
+
+	tr.Resolve(next).ServeHTTP(w, r)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	if gotTenantID != tenantID {
+		t.Errorf("expected tenant %s, got %s", tenantID, gotTenantID)
+	}
+}
+
+func TestTenantResolver_NoUser(t *testing.T) {
+	tr := NewTenantResolver(&mockTenantLookup{})
+	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Fatal("next should not be called")
+	})
+
+	r := httptest.NewRequest("GET", "/api/cases", nil)
+	w := httptest.NewRecorder()
+
+	tr.Resolve(next).ServeHTTP(w, r)
+
+	if w.Code != http.StatusUnauthorized {
+		t.Errorf("expected 401, got %d", w.Code)
+	}
+}
+
+func TestTenantResolver_InvalidHeader(t *testing.T) {
+	tr := NewTenantResolver(&mockTenantLookup{})
+	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Fatal("next should not be called")
+	})
+
+	r := httptest.NewRequest("GET", "/api/cases", nil)
+	r.Header.Set("X-Tenant-ID", "not-a-uuid")
+	r = r.WithContext(ContextWithUserID(r.Context(), uuid.New()))
+	w := httptest.NewRecorder()
+
+	tr.Resolve(next).ServeHTTP(w, r)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestTenantResolver_NoTenantForUser(t *testing.T) {
+	tr := NewTenantResolver(&mockTenantLookup{tenantID: nil})
+	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Fatal("next should not be called")
+	})
+
+	r := httptest.NewRequest("GET", "/api/cases", nil)
+	r = r.WithContext(ContextWithUserID(r.Context(), uuid.New()))
+	w := httptest.NewRecorder()
+
+	tr.Resolve(next).ServeHTTP(w, r)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400, got %d", w.Code)
+	}
+}

backend/internal/config/config.go

@@ -6,12 +6,13 @@ import (
 )
 
 type Config struct {
-	Port             string
+	Port              string
-	DatabaseURL      string
+	DatabaseURL       string
-	SupabaseURL      string
+	SupabaseURL       string
-	SupabaseAnonKey  string
+	SupabaseAnonKey   string
+	SupabaseServiceKey string
 	SupabaseJWTSecret string
-	AnthropicAPIKey  string
+	AnthropicAPIKey   string
 }
 
 func Load() (*Config, error) {
@@ -19,7 +20,8 @@ func Load() (*Config, error) {
 		Port:             getEnv("PORT", "8080"),
 		DatabaseURL:      os.Getenv("DATABASE_URL"),
 		SupabaseURL:      os.Getenv("SUPABASE_URL"),
-		SupabaseAnonKey:  os.Getenv("SUPABASE_ANON_KEY"),
+		SupabaseAnonKey:   os.Getenv("SUPABASE_ANON_KEY"),
+		SupabaseServiceKey: os.Getenv("SUPABASE_SERVICE_KEY"),
 		SupabaseJWTSecret: os.Getenv("SUPABASE_JWT_SECRET"),
 		AnthropicAPIKey:  os.Getenv("ANTHROPIC_API_KEY"),
 	}

backend/internal/handlers/ai.go

@@ -0,0 +1,115 @@
+package handlers
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+)
+
+type AIHandler struct {
+	ai *services.AIService
+	db *sqlx.DB
+}
+
+func NewAIHandler(ai *services.AIService, db *sqlx.DB) *AIHandler {
+	return &AIHandler{ai: ai, db: db}
+}
+
+// ExtractDeadlines handles POST /api/ai/extract-deadlines
+// Accepts either multipart/form-data with a "file" PDF field, or JSON {"text": "..."}.
+func (h *AIHandler) ExtractDeadlines(w http.ResponseWriter, r *http.Request) {
+	contentType := r.Header.Get("Content-Type")
+
+	var pdfData []byte
+	var text string
+
+	// Check if multipart (PDF upload)
+	if len(contentType) >= 9 && contentType[:9] == "multipart" {
+		if err := r.ParseMultipartForm(32 << 20); err != nil { // 32MB max
+			writeError(w, http.StatusBadRequest, "failed to parse multipart form")
+			return
+		}
+		file, _, err := r.FormFile("file")
+		if err != nil {
+			writeError(w, http.StatusBadRequest, "missing 'file' field in multipart form")
+			return
+		}
+		defer file.Close()
+
+		pdfData, err = io.ReadAll(file)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, "failed to read uploaded file")
+			return
+		}
+	} else {
+		// Assume JSON body
+		var body struct {
+			Text string `json:"text"`
+		}
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+			writeError(w, http.StatusBadRequest, "invalid request body")
+			return
+		}
+		text = body.Text
+	}
+
+	if len(pdfData) == 0 && text == "" {
+		writeError(w, http.StatusBadRequest, "provide either a PDF file or text")
+		return
+	}
+
+	deadlines, err := h.ai.ExtractDeadlines(r.Context(), pdfData, text)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "AI extraction failed: "+err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]any{
+		"deadlines": deadlines,
+		"count":     len(deadlines),
+	})
+}
+
+// SummarizeCase handles POST /api/ai/summarize-case
+// Accepts JSON {"case_id": "uuid"}.
+func (h *AIHandler) SummarizeCase(w http.ResponseWriter, r *http.Request) {
+	tenantID, err := resolveTenant(r, h.db)
+	if err != nil {
+		handleTenantError(w, err)
+		return
+	}
+
+	var body struct {
+		CaseID string `json:"case_id"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if body.CaseID == "" {
+		writeError(w, http.StatusBadRequest, "case_id is required")
+		return
+	}
+
+	caseID, err := parseUUID(body.CaseID)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case_id")
+		return
+	}
+
+	summary, err := h.ai.SummarizeCase(r.Context(), tenantID, caseID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "AI summarization failed: "+err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]string{
+		"case_id": caseID.String(),
+		"summary": summary,
+	})
+}

backend/internal/handlers/appointments.go

@@ -0,0 +1,205 @@
+package handlers
+
+import (
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"time"
+
+	"github.com/google/uuid"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+)
+
+type AppointmentHandler struct {
+	svc *services.AppointmentService
+}
+
+func NewAppointmentHandler(svc *services.AppointmentService) *AppointmentHandler {
+	return &AppointmentHandler{svc: svc}
+}
+
+func (h *AppointmentHandler) List(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusUnauthorized, "missing tenant")
+		return
+	}
+
+	filter := services.AppointmentFilter{}
+
+	if v := r.URL.Query().Get("case_id"); v != "" {
+		id, err := uuid.Parse(v)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, "invalid case_id")
+			return
+		}
+		filter.CaseID = &id
+	}
+	if v := r.URL.Query().Get("type"); v != "" {
+		filter.Type = &v
+	}
+	if v := r.URL.Query().Get("start_from"); v != "" {
+		t, err := time.Parse(time.RFC3339, v)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, "invalid start_from (use RFC3339)")
+			return
+		}
+		filter.StartFrom = &t
+	}
+	if v := r.URL.Query().Get("start_to"); v != "" {
+		t, err := time.Parse(time.RFC3339, v)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, "invalid start_to (use RFC3339)")
+			return
+		}
+		filter.StartTo = &t
+	}
+
+	appointments, err := h.svc.List(r.Context(), tenantID, filter)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to list appointments")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, appointments)
+}
+
+type createAppointmentRequest struct {
+	CaseID          *uuid.UUID `json:"case_id"`
+	Title           string     `json:"title"`
+	Description     *string    `json:"description"`
+	StartAt         time.Time  `json:"start_at"`
+	EndAt           *time.Time `json:"end_at"`
+	Location        *string    `json:"location"`
+	AppointmentType *string    `json:"appointment_type"`
+}
+
+func (h *AppointmentHandler) Create(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusUnauthorized, "missing tenant")
+		return
+	}
+
+	var req createAppointmentRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	if req.Title == "" {
+		writeError(w, http.StatusBadRequest, "title is required")
+		return
+	}
+	if req.StartAt.IsZero() {
+		writeError(w, http.StatusBadRequest, "start_at is required")
+		return
+	}
+
+	appt := &models.Appointment{
+		TenantID:        tenantID,
+		CaseID:          req.CaseID,
+		Title:           req.Title,
+		Description:     req.Description,
+		StartAt:         req.StartAt,
+		EndAt:           req.EndAt,
+		Location:        req.Location,
+		AppointmentType: req.AppointmentType,
+	}
+
+	if err := h.svc.Create(r.Context(), appt); err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to create appointment")
+		return
+	}
+
+	writeJSON(w, http.StatusCreated, appt)
+}
+
+type updateAppointmentRequest struct {
+	CaseID          *uuid.UUID `json:"case_id"`
+	Title           string     `json:"title"`
+	Description     *string    `json:"description"`
+	StartAt         time.Time  `json:"start_at"`
+	EndAt           *time.Time `json:"end_at"`
+	Location        *string    `json:"location"`
+	AppointmentType *string    `json:"appointment_type"`
+}
+
+func (h *AppointmentHandler) Update(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusUnauthorized, "missing tenant")
+		return
+	}
+
+	id, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid appointment id")
+		return
+	}
+
+	// Fetch existing to verify ownership
+	existing, err := h.svc.GetByID(r.Context(), tenantID, id)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			writeError(w, http.StatusNotFound, "appointment not found")
+			return
+		}
+		writeError(w, http.StatusInternalServerError, "failed to fetch appointment")
+		return
+	}
+
+	var req updateAppointmentRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	if req.Title == "" {
+		writeError(w, http.StatusBadRequest, "title is required")
+		return
+	}
+	if req.StartAt.IsZero() {
+		writeError(w, http.StatusBadRequest, "start_at is required")
+		return
+	}
+
+	existing.CaseID = req.CaseID
+	existing.Title = req.Title
+	existing.Description = req.Description
+	existing.StartAt = req.StartAt
+	existing.EndAt = req.EndAt
+	existing.Location = req.Location
+	existing.AppointmentType = req.AppointmentType
+
+	if err := h.svc.Update(r.Context(), existing); err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to update appointment")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, existing)
+}
+
+func (h *AppointmentHandler) Delete(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusUnauthorized, "missing tenant")
+		return
+	}
+
+	id, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid appointment id")
+		return
+	}
+
+	if err := h.svc.Delete(r.Context(), tenantID, id); err != nil {
+		writeError(w, http.StatusNotFound, "appointment not found")
+		return
+	}
+
+	w.WriteHeader(http.StatusNoContent)
+}
+

backend/internal/handlers/calculate.go

@@ -0,0 +1,89 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+)
+
+// CalculateHandlers holds handlers for deadline calculation endpoints
+type CalculateHandlers struct {
+	calculator *services.DeadlineCalculator
+	rules      *services.DeadlineRuleService
+}
+
+// NewCalculateHandlers creates calculate handlers
+func NewCalculateHandlers(calc *services.DeadlineCalculator, rules *services.DeadlineRuleService) *CalculateHandlers {
+	return &CalculateHandlers{calculator: calc, rules: rules}
+}
+
+// CalculateRequest is the input for POST /api/deadlines/calculate
+type CalculateRequest struct {
+	ProceedingType   string   `json:"proceeding_type"`
+	TriggerEventDate string   `json:"trigger_event_date"`
+	SelectedRuleIDs  []string `json:"selected_rule_ids,omitempty"`
+}
+
+// Calculate handles POST /api/deadlines/calculate
+func (h *CalculateHandlers) Calculate(w http.ResponseWriter, r *http.Request) {
+	var req CalculateRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if req.ProceedingType == "" || req.TriggerEventDate == "" {
+		writeError(w, http.StatusBadRequest, "proceeding_type and trigger_event_date are required")
+		return
+	}
+
+	eventDate, err := time.Parse("2006-01-02", req.TriggerEventDate)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid trigger_event_date format, expected YYYY-MM-DD")
+		return
+	}
+
+	var results []services.CalculatedDeadline
+
+	if len(req.SelectedRuleIDs) > 0 {
+		ruleModels, err := h.rules.GetByIDs(req.SelectedRuleIDs)
+		if err != nil {
+			writeError(w, http.StatusInternalServerError, "failed to fetch selected rules")
+			return
+		}
+		results = h.calculator.CalculateFromRules(eventDate, ruleModels)
+	} else {
+		tree, err := h.rules.GetRuleTree(req.ProceedingType)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, "unknown proceeding type")
+			return
+		}
+		// Flatten tree to get all rule models
+		var flatNodes []services.RuleTreeNode
+		flattenTree(tree, &flatNodes)
+
+		ruleModels := make([]models.DeadlineRule, 0, len(flatNodes))
+		for _, node := range flatNodes {
+			ruleModels = append(ruleModels, node.DeadlineRule)
+		}
+		results = h.calculator.CalculateFromRules(eventDate, ruleModels)
+	}
+
+	writeJSON(w, http.StatusOK, map[string]any{
+		"proceeding_type":    req.ProceedingType,
+		"trigger_event_date": req.TriggerEventDate,
+		"deadlines":          results,
+	})
+}
+
+func flattenTree(nodes []services.RuleTreeNode, result *[]services.RuleTreeNode) {
+	for _, n := range nodes {
+		*result = append(*result, n)
+		if len(n.Children) > 0 {
+			flattenTree(n.Children, result)
+		}
+	}
+}

backend/internal/handlers/cases.go

@@ -0,0 +1,158 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"strconv"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+
+	"github.com/google/uuid"
+)
+
+type CaseHandler struct {
+	svc *services.CaseService
+}
+
+func NewCaseHandler(svc *services.CaseService) *CaseHandler {
+	return &CaseHandler{svc: svc}
+}
+
+func (h *CaseHandler) List(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	limit, _ := strconv.Atoi(r.URL.Query().Get("limit"))
+	offset, _ := strconv.Atoi(r.URL.Query().Get("offset"))
+
+	filter := services.CaseFilter{
+		Status: r.URL.Query().Get("status"),
+		Type:   r.URL.Query().Get("type"),
+		Search: r.URL.Query().Get("search"),
+		Limit:  limit,
+		Offset: offset,
+	}
+
+	cases, total, err := h.svc.List(r.Context(), tenantID, filter)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]interface{}{
+		"cases": cases,
+		"total": total,
+	})
+}
+
+func (h *CaseHandler) Create(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+	userID, _ := auth.UserFromContext(r.Context())
+
+	var input services.CreateCaseInput
+	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	if input.CaseNumber == "" || input.Title == "" {
+		writeError(w, http.StatusBadRequest, "case_number and title are required")
+		return
+	}
+
+	c, err := h.svc.Create(r.Context(), tenantID, userID, input)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusCreated, c)
+}
+
+func (h *CaseHandler) Get(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	caseID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	detail, err := h.svc.GetByID(r.Context(), tenantID, caseID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if detail == nil {
+		writeError(w, http.StatusNotFound, "case not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, detail)
+}
+
+func (h *CaseHandler) Update(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+	userID, _ := auth.UserFromContext(r.Context())
+
+	caseID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	var input services.UpdateCaseInput
+	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+
+	updated, err := h.svc.Update(r.Context(), tenantID, caseID, userID, input)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if updated == nil {
+		writeError(w, http.StatusNotFound, "case not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, updated)
+}
+
+func (h *CaseHandler) Delete(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+	userID, _ := auth.UserFromContext(r.Context())
+
+	caseID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	if err := h.svc.Delete(r.Context(), tenantID, caseID, userID); err != nil {
+		writeError(w, http.StatusNotFound, "case not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]string{"status": "archived"})
+}

backend/internal/handlers/dashboard.go

@@ -0,0 +1,32 @@
+package handlers
+
+import (
+	"net/http"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+)
+
+type DashboardHandler struct {
+	svc *services.DashboardService
+}
+
+func NewDashboardHandler(svc *services.DashboardService) *DashboardHandler {
+	return &DashboardHandler{svc: svc}
+}
+
+func (h *DashboardHandler) Get(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	data, err := h.svc.Get(r.Context(), tenantID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, data)
+}

backend/internal/handlers/deadline_rules.go

@@ -0,0 +1,58 @@
+package handlers
+
+import (
+	"net/http"
+	"strconv"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+)
+
+// DeadlineRuleHandlers holds handlers for deadline rule endpoints
+type DeadlineRuleHandlers struct {
+	rules *services.DeadlineRuleService
+}
+
+// NewDeadlineRuleHandlers creates deadline rule handlers
+func NewDeadlineRuleHandlers(rs *services.DeadlineRuleService) *DeadlineRuleHandlers {
+	return &DeadlineRuleHandlers{rules: rs}
+}
+
+// List handles GET /api/deadline-rules
+// Query params: proceeding_type_id (optional int filter)
+func (h *DeadlineRuleHandlers) List(w http.ResponseWriter, r *http.Request) {
+	var proceedingTypeID *int
+	if v := r.URL.Query().Get("proceeding_type_id"); v != "" {
+		id, err := strconv.Atoi(v)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, "invalid proceeding_type_id")
+			return
+		}
+		proceedingTypeID = &id
+	}
+
+	rules, err := h.rules.List(proceedingTypeID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to list deadline rules")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, rules)
+}
+
+// GetRuleTree handles GET /api/deadline-rules/{type}
+// {type} is the proceeding type code (e.g., "INF", "REV")
+func (h *DeadlineRuleHandlers) GetRuleTree(w http.ResponseWriter, r *http.Request) {
+	typeCode := r.PathValue("type")
+	if typeCode == "" {
+		writeError(w, http.StatusBadRequest, "proceeding type code required")
+		return
+	}
+
+	tree, err := h.rules.GetRuleTree(typeCode)
+	if err != nil {
+		writeError(w, http.StatusNotFound, "proceeding type not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, tree)
+}

backend/internal/handlers/deadlines.go

@@ -0,0 +1,162 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+)
+
+// DeadlineHandlers holds handlers for deadline CRUD endpoints
+type DeadlineHandlers struct {
+	deadlines *services.DeadlineService
+	db        *sqlx.DB
+}
+
+// NewDeadlineHandlers creates deadline handlers
+func NewDeadlineHandlers(ds *services.DeadlineService, db *sqlx.DB) *DeadlineHandlers {
+	return &DeadlineHandlers{deadlines: ds, db: db}
+}
+
+// ListForCase handles GET /api/cases/{caseID}/deadlines
+func (h *DeadlineHandlers) ListForCase(w http.ResponseWriter, r *http.Request) {
+	tenantID, err := resolveTenant(r, h.db)
+	if err != nil {
+		handleTenantError(w, err)
+		return
+	}
+
+	caseID, err := parsePathUUID(r, "caseID")
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	deadlines, err := h.deadlines.ListForCase(tenantID, caseID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to list deadlines")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, deadlines)
+}
+
+// Create handles POST /api/cases/{caseID}/deadlines
+func (h *DeadlineHandlers) Create(w http.ResponseWriter, r *http.Request) {
+	tenantID, err := resolveTenant(r, h.db)
+	if err != nil {
+		handleTenantError(w, err)
+		return
+	}
+
+	caseID, err := parsePathUUID(r, "caseID")
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	var input services.CreateDeadlineInput
+	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	input.CaseID = caseID
+
+	if input.Title == "" || input.DueDate == "" {
+		writeError(w, http.StatusBadRequest, "title and due_date are required")
+		return
+	}
+
+	deadline, err := h.deadlines.Create(tenantID, input)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to create deadline")
+		return
+	}
+
+	writeJSON(w, http.StatusCreated, deadline)
+}
+
+// Update handles PUT /api/deadlines/{deadlineID}
+func (h *DeadlineHandlers) Update(w http.ResponseWriter, r *http.Request) {
+	tenantID, err := resolveTenant(r, h.db)
+	if err != nil {
+		handleTenantError(w, err)
+		return
+	}
+
+	deadlineID, err := parsePathUUID(r, "deadlineID")
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid deadline ID")
+		return
+	}
+
+	var input services.UpdateDeadlineInput
+	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	deadline, err := h.deadlines.Update(tenantID, deadlineID, input)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to update deadline")
+		return
+	}
+	if deadline == nil {
+		writeError(w, http.StatusNotFound, "deadline not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, deadline)
+}
+
+// Complete handles PATCH /api/deadlines/{deadlineID}/complete
+func (h *DeadlineHandlers) Complete(w http.ResponseWriter, r *http.Request) {
+	tenantID, err := resolveTenant(r, h.db)
+	if err != nil {
+		handleTenantError(w, err)
+		return
+	}
+
+	deadlineID, err := parsePathUUID(r, "deadlineID")
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid deadline ID")
+		return
+	}
+
+	deadline, err := h.deadlines.Complete(tenantID, deadlineID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to complete deadline")
+		return
+	}
+	if deadline == nil {
+		writeError(w, http.StatusNotFound, "deadline not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, deadline)
+}
+
+// Delete handles DELETE /api/deadlines/{deadlineID}
+func (h *DeadlineHandlers) Delete(w http.ResponseWriter, r *http.Request) {
+	tenantID, err := resolveTenant(r, h.db)
+	if err != nil {
+		handleTenantError(w, err)
+		return
+	}
+
+	deadlineID, err := parsePathUUID(r, "deadlineID")
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid deadline ID")
+		return
+	}
+
+	err = h.deadlines.Delete(tenantID, deadlineID)
+	if err != nil {
+		writeError(w, http.StatusNotFound, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
+}

backend/internal/handlers/documents.go

@@ -0,0 +1,183 @@
+package handlers
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+
+	"github.com/google/uuid"
+)
+
+const maxUploadSize = 50 << 20 // 50 MB
+
+type DocumentHandler struct {
+	svc *services.DocumentService
+}
+
+func NewDocumentHandler(svc *services.DocumentService) *DocumentHandler {
+	return &DocumentHandler{svc: svc}
+}
+
+func (h *DocumentHandler) ListByCase(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	caseID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	docs, err := h.svc.ListByCase(r.Context(), tenantID, caseID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]any{
+		"documents": docs,
+		"total":     len(docs),
+	})
+}
+
+func (h *DocumentHandler) Upload(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+	userID, _ := auth.UserFromContext(r.Context())
+
+	caseID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	r.Body = http.MaxBytesReader(w, r.Body, maxUploadSize)
+	if err := r.ParseMultipartForm(maxUploadSize); err != nil {
+		writeError(w, http.StatusBadRequest, "file too large or invalid multipart form")
+		return
+	}
+
+	file, header, err := r.FormFile("file")
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "missing file field")
+		return
+	}
+	defer file.Close()
+
+	title := r.FormValue("title")
+	if title == "" {
+		title = header.Filename
+	}
+
+	contentType := header.Header.Get("Content-Type")
+	if contentType == "" {
+		contentType = "application/octet-stream"
+	}
+
+	input := services.CreateDocumentInput{
+		Title:       title,
+		DocType:     r.FormValue("doc_type"),
+		Filename:    header.Filename,
+		ContentType: contentType,
+		Size:        int(header.Size),
+		Data:        file,
+	}
+
+	doc, err := h.svc.Create(r.Context(), tenantID, caseID, userID, input)
+	if err != nil {
+		if err.Error() == "case not found" {
+			writeError(w, http.StatusNotFound, "case not found")
+			return
+		}
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusCreated, doc)
+}
+
+func (h *DocumentHandler) Download(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	docID, err := uuid.Parse(r.PathValue("docId"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid document ID")
+		return
+	}
+
+	body, contentType, title, err := h.svc.Download(r.Context(), tenantID, docID)
+	if err != nil {
+		if err.Error() == "document not found" || err.Error() == "document has no file" {
+			writeError(w, http.StatusNotFound, err.Error())
+			return
+		}
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	defer body.Close()
+
+	w.Header().Set("Content-Type", contentType)
+	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, title))
+	io.Copy(w, body)
+}
+
+func (h *DocumentHandler) GetMeta(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	docID, err := uuid.Parse(r.PathValue("docId"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid document ID")
+		return
+	}
+
+	doc, err := h.svc.GetByID(r.Context(), tenantID, docID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if doc == nil {
+		writeError(w, http.StatusNotFound, "document not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, doc)
+}
+
+func (h *DocumentHandler) Delete(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+	userID, _ := auth.UserFromContext(r.Context())
+
+	docID, err := uuid.Parse(r.PathValue("docId"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid document ID")
+		return
+	}
+
+	if err := h.svc.Delete(r.Context(), tenantID, docID, userID); err != nil {
+		writeError(w, http.StatusNotFound, "document not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
+}

backend/internal/handlers/helpers.go

@@ -0,0 +1,90 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+)
+
+func writeJSON(w http.ResponseWriter, status int, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	json.NewEncoder(w).Encode(v)
+}
+
+func writeError(w http.ResponseWriter, status int, msg string) {
+	writeJSON(w, status, map[string]string{"error": msg})
+}
+
+// resolveTenant gets the tenant ID for the authenticated user.
+// Checks X-Tenant-ID header first, then falls back to user's first tenant.
+func resolveTenant(r *http.Request, db *sqlx.DB) (uuid.UUID, error) {
+	userID, ok := auth.UserFromContext(r.Context())
+	if !ok {
+		return uuid.Nil, errUnauthorized
+	}
+
+	// Check header first
+	if headerVal := r.Header.Get("X-Tenant-ID"); headerVal != "" {
+		tenantID, err := uuid.Parse(headerVal)
+		if err != nil {
+			return uuid.Nil, errInvalidTenant
+		}
+		// Verify user has access to this tenant
+		var count int
+		err = db.Get(&count,
+			`SELECT COUNT(*) FROM user_tenants WHERE user_id = $1 AND tenant_id = $2`,
+			userID, tenantID)
+		if err != nil || count == 0 {
+			return uuid.Nil, errTenantAccess
+		}
+		return tenantID, nil
+	}
+
+	// Fall back to user's first tenant
+	var tenantID uuid.UUID
+	err := db.Get(&tenantID,
+		`SELECT tenant_id FROM user_tenants WHERE user_id = $1 ORDER BY created_at LIMIT 1`,
+		userID)
+	if err != nil {
+		return uuid.Nil, errNoTenant
+	}
+	return tenantID, nil
+}
+
+type apiError struct {
+	msg    string
+	status int
+}
+
+func (e *apiError) Error() string { return e.msg }
+
+var (
+	errUnauthorized = &apiError{msg: "unauthorized", status: http.StatusUnauthorized}
+	errInvalidTenant = &apiError{msg: "invalid tenant ID", status: http.StatusBadRequest}
+	errTenantAccess  = &apiError{msg: "no access to tenant", status: http.StatusForbidden}
+	errNoTenant      = &apiError{msg: "no tenant found for user", status: http.StatusBadRequest}
+)
+
+// handleTenantError writes the appropriate error response for tenant resolution errors
+func handleTenantError(w http.ResponseWriter, err error) {
+	if ae, ok := err.(*apiError); ok {
+		writeError(w, ae.status, ae.msg)
+		return
+	}
+	writeError(w, http.StatusInternalServerError, "internal error")
+}
+
+// parsePathUUID extracts a UUID from the URL path using PathValue
+func parsePathUUID(r *http.Request, key string) (uuid.UUID, error) {
+	return uuid.Parse(r.PathValue(key))
+}
+
+// parseUUID parses a UUID string
+func parseUUID(s string) (uuid.UUID, error) {
+	return uuid.Parse(s)
+}

backend/internal/handlers/parties.go

@@ -0,0 +1,134 @@
+package handlers
+
+import (
+	"database/sql"
+	"encoding/json"
+	"net/http"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+
+	"github.com/google/uuid"
+)
+
+type PartyHandler struct {
+	svc *services.PartyService
+}
+
+func NewPartyHandler(svc *services.PartyService) *PartyHandler {
+	return &PartyHandler{svc: svc}
+}
+
+func (h *PartyHandler) List(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	caseID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	parties, err := h.svc.ListByCase(r.Context(), tenantID, caseID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]interface{}{
+		"parties": parties,
+	})
+}
+
+func (h *PartyHandler) Create(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+	userID, _ := auth.UserFromContext(r.Context())
+
+	caseID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid case ID")
+		return
+	}
+
+	var input services.CreatePartyInput
+	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	if input.Name == "" {
+		writeError(w, http.StatusBadRequest, "name is required")
+		return
+	}
+
+	party, err := h.svc.Create(r.Context(), tenantID, caseID, userID, input)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			writeError(w, http.StatusNotFound, "case not found")
+			return
+		}
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusCreated, party)
+}
+
+func (h *PartyHandler) Update(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	partyID, err := uuid.Parse(r.PathValue("partyId"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid party ID")
+		return
+	}
+
+	var input services.UpdatePartyInput
+	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+
+	updated, err := h.svc.Update(r.Context(), tenantID, partyID, input)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if updated == nil {
+		writeError(w, http.StatusNotFound, "party not found")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, updated)
+}
+
+func (h *PartyHandler) Delete(w http.ResponseWriter, r *http.Request) {
+	tenantID, ok := auth.TenantFromContext(r.Context())
+	if !ok {
+		writeError(w, http.StatusForbidden, "missing tenant")
+		return
+	}
+
+	partyID, err := uuid.Parse(r.PathValue("partyId"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid party ID")
+		return
+	}
+
+	if err := h.svc.Delete(r.Context(), tenantID, partyID); err != nil {
+		writeError(w, http.StatusNotFound, "party not found")
+		return
+	}
+
+	w.WriteHeader(http.StatusNoContent)
+}

backend/internal/handlers/tenant_handler.go

@@ -0,0 +1,243 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/google/uuid"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
+)
+
+type TenantHandler struct {
+	svc *services.TenantService
+}
+
+func NewTenantHandler(svc *services.TenantService) *TenantHandler {
+	return &TenantHandler{svc: svc}
+}
+
+// CreateTenant handles POST /api/tenants
+func (h *TenantHandler) CreateTenant(w http.ResponseWriter, r *http.Request) {
+	userID, ok := auth.UserFromContext(r.Context())
+	if !ok {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+
+	var req struct {
+		Name string `json:"name"`
+		Slug string `json:"slug"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		jsonError(w, "invalid request body", http.StatusBadRequest)
+		return
+	}
+	if req.Name == "" || req.Slug == "" {
+		jsonError(w, "name and slug are required", http.StatusBadRequest)
+		return
+	}
+
+	tenant, err := h.svc.Create(r.Context(), userID, req.Name, req.Slug)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	jsonResponse(w, tenant, http.StatusCreated)
+}
+
+// ListTenants handles GET /api/tenants
+func (h *TenantHandler) ListTenants(w http.ResponseWriter, r *http.Request) {
+	userID, ok := auth.UserFromContext(r.Context())
+	if !ok {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+
+	tenants, err := h.svc.ListForUser(r.Context(), userID)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	jsonResponse(w, tenants, http.StatusOK)
+}
+
+// GetTenant handles GET /api/tenants/{id}
+func (h *TenantHandler) GetTenant(w http.ResponseWriter, r *http.Request) {
+	userID, ok := auth.UserFromContext(r.Context())
+	if !ok {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+
+	tenantID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		jsonError(w, "invalid tenant ID", http.StatusBadRequest)
+		return
+	}
+
+	// Verify user has access to this tenant
+	role, err := h.svc.GetUserRole(r.Context(), userID, tenantID)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if role == "" {
+		jsonError(w, "not found", http.StatusNotFound)
+		return
+	}
+
+	tenant, err := h.svc.GetByID(r.Context(), tenantID)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if tenant == nil {
+		jsonError(w, "not found", http.StatusNotFound)
+		return
+	}
+
+	jsonResponse(w, tenant, http.StatusOK)
+}
+
+// InviteUser handles POST /api/tenants/{id}/invite
+func (h *TenantHandler) InviteUser(w http.ResponseWriter, r *http.Request) {
+	userID, ok := auth.UserFromContext(r.Context())
+	if !ok {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+
+	tenantID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		jsonError(w, "invalid tenant ID", http.StatusBadRequest)
+		return
+	}
+
+	// Only owners and admins can invite
+	role, err := h.svc.GetUserRole(r.Context(), userID, tenantID)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if role != "owner" && role != "admin" {
+		jsonError(w, "only owners and admins can invite users", http.StatusForbidden)
+		return
+	}
+
+	var req struct {
+		Email string `json:"email"`
+		Role  string `json:"role"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		jsonError(w, "invalid request body", http.StatusBadRequest)
+		return
+	}
+	if req.Email == "" {
+		jsonError(w, "email is required", http.StatusBadRequest)
+		return
+	}
+	if req.Role == "" {
+		req.Role = "member"
+	}
+	if req.Role != "member" && req.Role != "admin" {
+		jsonError(w, "role must be member or admin", http.StatusBadRequest)
+		return
+	}
+
+	ut, err := h.svc.InviteByEmail(r.Context(), tenantID, req.Email, req.Role)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	jsonResponse(w, ut, http.StatusCreated)
+}
+
+// RemoveMember handles DELETE /api/tenants/{id}/members/{uid}
+func (h *TenantHandler) RemoveMember(w http.ResponseWriter, r *http.Request) {
+	userID, ok := auth.UserFromContext(r.Context())
+	if !ok {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+
+	tenantID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		jsonError(w, "invalid tenant ID", http.StatusBadRequest)
+		return
+	}
+
+	memberID, err := uuid.Parse(r.PathValue("uid"))
+	if err != nil {
+		jsonError(w, "invalid member ID", http.StatusBadRequest)
+		return
+	}
+
+	// Only owners and admins can remove members (or user removing themselves)
+	role, err := h.svc.GetUserRole(r.Context(), userID, tenantID)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if role != "owner" && role != "admin" && userID != memberID {
+		jsonError(w, "insufficient permissions", http.StatusForbidden)
+		return
+	}
+
+	if err := h.svc.RemoveMember(r.Context(), tenantID, memberID); err != nil {
+		jsonError(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	jsonResponse(w, map[string]string{"status": "removed"}, http.StatusOK)
+}
+
+// ListMembers handles GET /api/tenants/{id}/members
+func (h *TenantHandler) ListMembers(w http.ResponseWriter, r *http.Request) {
+	userID, ok := auth.UserFromContext(r.Context())
+	if !ok {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+
+	tenantID, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		jsonError(w, "invalid tenant ID", http.StatusBadRequest)
+		return
+	}
+
+	// Verify user has access
+	role, err := h.svc.GetUserRole(r.Context(), userID, tenantID)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if role == "" {
+		jsonError(w, "not found", http.StatusNotFound)
+		return
+	}
+
+	members, err := h.svc.ListMembers(r.Context(), tenantID)
+	if err != nil {
+		jsonError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	jsonResponse(w, members, http.StatusOK)
+}
+
+func jsonResponse(w http.ResponseWriter, data interface{}, status int) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	json.NewEncoder(w).Encode(data)
+}
+
+func jsonError(w http.ResponseWriter, msg string, status int) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	json.NewEncoder(w).Encode(map[string]string{"error": msg})
+}

backend/internal/handlers/tenant_handler_test.go

@@ -0,0 +1,132 @@
+package handlers
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/google/uuid"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+)
+
+func TestCreateTenant_MissingFields(t *testing.T) {
+	h := &TenantHandler{} // no service needed for validation
+
+	// Build request with auth context
+	body := `{"name":"","slug":""}`
+	r := httptest.NewRequest("POST", "/api/tenants", bytes.NewBufferString(body))
+	r = r.WithContext(auth.ContextWithUserID(r.Context(), uuid.New()))
+	w := httptest.NewRecorder()
+
+	h.CreateTenant(w, r)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400, got %d", w.Code)
+	}
+
+	var resp map[string]string
+	json.NewDecoder(w.Body).Decode(&resp)
+	if resp["error"] != "name and slug are required" {
+		t.Errorf("unexpected error: %s", resp["error"])
+	}
+}
+
+func TestCreateTenant_NoAuth(t *testing.T) {
+	h := &TenantHandler{}
+	r := httptest.NewRequest("POST", "/api/tenants", bytes.NewBufferString(`{}`))
+	w := httptest.NewRecorder()
+
+	h.CreateTenant(w, r)
+
+	if w.Code != http.StatusUnauthorized {
+		t.Errorf("expected 401, got %d", w.Code)
+	}
+}
+
+func TestGetTenant_InvalidID(t *testing.T) {
+	h := &TenantHandler{}
+	r := httptest.NewRequest("GET", "/api/tenants/not-a-uuid", nil)
+	r.SetPathValue("id", "not-a-uuid")
+	r = r.WithContext(auth.ContextWithUserID(r.Context(), uuid.New()))
+	w := httptest.NewRecorder()
+
+	h.GetTenant(w, r)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestInviteUser_InvalidTenantID(t *testing.T) {
+	h := &TenantHandler{}
+	body := `{"email":"test@example.com","role":"member"}`
+	r := httptest.NewRequest("POST", "/api/tenants/bad/invite", bytes.NewBufferString(body))
+	r.SetPathValue("id", "bad")
+	r = r.WithContext(auth.ContextWithUserID(r.Context(), uuid.New()))
+	w := httptest.NewRecorder()
+
+	h.InviteUser(w, r)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestInviteUser_NoAuth(t *testing.T) {
+	h := &TenantHandler{}
+	body := `{"email":"test@example.com"}`
+	r := httptest.NewRequest("POST", "/api/tenants/"+uuid.New().String()+"/invite", bytes.NewBufferString(body))
+	r.SetPathValue("id", uuid.New().String())
+	w := httptest.NewRecorder()
+
+	h.InviteUser(w, r)
+
+	if w.Code != http.StatusUnauthorized {
+		t.Errorf("expected 401, got %d", w.Code)
+	}
+}
+
+func TestRemoveMember_InvalidIDs(t *testing.T) {
+	h := &TenantHandler{}
+	r := httptest.NewRequest("DELETE", "/api/tenants/bad/members/bad", nil)
+	r.SetPathValue("id", "bad")
+	r.SetPathValue("uid", "bad")
+	r = r.WithContext(auth.ContextWithUserID(r.Context(), uuid.New()))
+	w := httptest.NewRecorder()
+
+	h.RemoveMember(w, r)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestJsonResponse(t *testing.T) {
+	w := httptest.NewRecorder()
+	jsonResponse(w, map[string]string{"key": "value"}, http.StatusOK)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("expected 200, got %d", w.Code)
+	}
+	if ct := w.Header().Get("Content-Type"); ct != "application/json" {
+		t.Errorf("expected application/json, got %s", ct)
+	}
+}
+
+func TestJsonError(t *testing.T) {
+	w := httptest.NewRecorder()
+	jsonError(w, "something went wrong", http.StatusBadRequest)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400, got %d", w.Code)
+	}
+
+	var resp map[string]string
+	json.NewDecoder(w.Body).Decode(&resp)
+	if resp["error"] != "something went wrong" {
+		t.Errorf("unexpected error: %s", resp["error"])
+	}
+}

backend/internal/models/tenant.go

@@ -22,3 +22,9 @@ type UserTenant struct {
 	Role      string    `db:"role" json:"role"`
 	CreatedAt time.Time `db:"created_at" json:"created_at"`
 }
+
+// TenantWithRole is a Tenant joined with the user's role in that tenant.
+type TenantWithRole struct {
+	Tenant
+	Role string `db:"role" json:"role"`
+}

backend/internal/router/router.go

@@ -4,23 +4,120 @@ import (
 	"encoding/json"
 	"net/http"
 
-	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
-
 	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/auth"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/config"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/handlers"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
 )
 
-func New(db *sqlx.DB, authMW *auth.Middleware) http.Handler {
+func New(db *sqlx.DB, authMW *auth.Middleware, cfg *config.Config) http.Handler {
 	mux := http.NewServeMux()
 
+	// Services
+	tenantSvc := services.NewTenantService(db)
+	caseSvc := services.NewCaseService(db)
+	partySvc := services.NewPartyService(db)
+	appointmentSvc := services.NewAppointmentService(db)
+	holidaySvc := services.NewHolidayService(db)
+	deadlineSvc := services.NewDeadlineService(db)
+	deadlineRuleSvc := services.NewDeadlineRuleService(db)
+	calculator := services.NewDeadlineCalculator(holidaySvc)
+	storageCli := services.NewStorageClient(cfg.SupabaseURL, cfg.SupabaseServiceKey)
+	documentSvc := services.NewDocumentService(db, storageCli)
+
+	// AI service (optional — only if API key is configured)
+	var aiH *handlers.AIHandler
+	if cfg.AnthropicAPIKey != "" {
+		aiSvc := services.NewAIService(cfg.AnthropicAPIKey, db)
+		aiH = handlers.NewAIHandler(aiSvc, db)
+	}
+
+	// Middleware
+	tenantResolver := auth.NewTenantResolver(tenantSvc)
+
+	dashboardSvc := services.NewDashboardService(db)
+
+	// Handlers
+	tenantH := handlers.NewTenantHandler(tenantSvc)
+	caseH := handlers.NewCaseHandler(caseSvc)
+	partyH := handlers.NewPartyHandler(partySvc)
+	apptH := handlers.NewAppointmentHandler(appointmentSvc)
+	deadlineH := handlers.NewDeadlineHandlers(deadlineSvc, db)
+	ruleH := handlers.NewDeadlineRuleHandlers(deadlineRuleSvc)
+	calcH := handlers.NewCalculateHandlers(calculator, deadlineRuleSvc)
+	dashboardH := handlers.NewDashboardHandler(dashboardSvc)
+	docH := handlers.NewDocumentHandler(documentSvc)
+
 	// Public routes
 	mux.HandleFunc("GET /health", handleHealth(db))
 
 	// Authenticated API routes
 	api := http.NewServeMux()
-	api.HandleFunc("GET /api/cases", placeholder("cases"))
+
-	api.HandleFunc("GET /api/deadlines", placeholder("deadlines"))
+	// Tenant management (no tenant resolver — these operate across tenants)
-	api.HandleFunc("GET /api/appointments", placeholder("appointments"))
+	api.HandleFunc("POST /api/tenants", tenantH.CreateTenant)
-	api.HandleFunc("GET /api/documents", placeholder("documents"))
+	api.HandleFunc("GET /api/tenants", tenantH.ListTenants)
+	api.HandleFunc("GET /api/tenants/{id}", tenantH.GetTenant)
+	api.HandleFunc("POST /api/tenants/{id}/invite", tenantH.InviteUser)
+	api.HandleFunc("DELETE /api/tenants/{id}/members/{uid}", tenantH.RemoveMember)
+	api.HandleFunc("GET /api/tenants/{id}/members", tenantH.ListMembers)
+
+	// Tenant-scoped routes (require tenant context)
+	scoped := http.NewServeMux()
+
+	// Cases
+	scoped.HandleFunc("GET /api/cases", caseH.List)
+	scoped.HandleFunc("POST /api/cases", caseH.Create)
+	scoped.HandleFunc("GET /api/cases/{id}", caseH.Get)
+	scoped.HandleFunc("PUT /api/cases/{id}", caseH.Update)
+	scoped.HandleFunc("DELETE /api/cases/{id}", caseH.Delete)
+
+	// Parties
+	scoped.HandleFunc("GET /api/cases/{id}/parties", partyH.List)
+	scoped.HandleFunc("POST /api/cases/{id}/parties", partyH.Create)
+	scoped.HandleFunc("PUT /api/parties/{partyId}", partyH.Update)
+	scoped.HandleFunc("DELETE /api/parties/{partyId}", partyH.Delete)
+
+	// Deadlines
+	scoped.HandleFunc("GET /api/cases/{caseID}/deadlines", deadlineH.ListForCase)
+	scoped.HandleFunc("POST /api/cases/{caseID}/deadlines", deadlineH.Create)
+	scoped.HandleFunc("PUT /api/deadlines/{deadlineID}", deadlineH.Update)
+	scoped.HandleFunc("PATCH /api/deadlines/{deadlineID}/complete", deadlineH.Complete)
+	scoped.HandleFunc("DELETE /api/deadlines/{deadlineID}", deadlineH.Delete)
+
+	// Deadline rules (reference data)
+	scoped.HandleFunc("GET /api/deadline-rules", ruleH.List)
+	scoped.HandleFunc("GET /api/deadline-rules/{type}", ruleH.GetRuleTree)
+
+	// Deadline calculator
+	scoped.HandleFunc("POST /api/deadlines/calculate", calcH.Calculate)
+
+	// Appointments
+	scoped.HandleFunc("GET /api/appointments", apptH.List)
+	scoped.HandleFunc("POST /api/appointments", apptH.Create)
+	scoped.HandleFunc("PUT /api/appointments/{id}", apptH.Update)
+	scoped.HandleFunc("DELETE /api/appointments/{id}", apptH.Delete)
+
+	// Dashboard
+	scoped.HandleFunc("GET /api/dashboard", dashboardH.Get)
+
+	// Documents
+	scoped.HandleFunc("GET /api/cases/{id}/documents", docH.ListByCase)
+	scoped.HandleFunc("POST /api/cases/{id}/documents", docH.Upload)
+	scoped.HandleFunc("GET /api/documents/{docId}", docH.Download)
+	scoped.HandleFunc("GET /api/documents/{docId}/meta", docH.GetMeta)
+	scoped.HandleFunc("DELETE /api/documents/{docId}", docH.Delete)
+
+	// AI endpoints
+	if aiH != nil {
+		scoped.HandleFunc("POST /api/ai/extract-deadlines", aiH.ExtractDeadlines)
+		scoped.HandleFunc("POST /api/ai/summarize-case", aiH.SummarizeCase)
+	}
+
+	// Wire: auth -> tenant routes go directly, scoped routes get tenant resolver
+	api.Handle("/api/", tenantResolver.Resolve(scoped))
 
 	mux.Handle("/api/", authMW.RequireAuth(api))
 
@@ -39,12 +136,3 @@ func handleHealth(db *sqlx.DB) http.HandlerFunc {
 	}
 }
 
-func placeholder(resource string) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode(map[string]string{
-			"status":   "not_implemented",
-			"resource": resource,
-		})
-	}
-}

backend/internal/services/ai_service.go

@@ -0,0 +1,283 @@
+package services
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/anthropics/anthropic-sdk-go"
+	"github.com/anthropics/anthropic-sdk-go/option"
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+)
+
+type AIService struct {
+	client anthropic.Client
+	db     *sqlx.DB
+}
+
+func NewAIService(apiKey string, db *sqlx.DB) *AIService {
+	client := anthropic.NewClient(option.WithAPIKey(apiKey))
+	return &AIService{client: client, db: db}
+}
+
+// ExtractedDeadline represents a deadline extracted by AI from a document.
+type ExtractedDeadline struct {
+	Title         string  `json:"title"`
+	DueDate       *string `json:"due_date"`
+	DurationValue int     `json:"duration_value"`
+	DurationUnit  string  `json:"duration_unit"`
+	Timing        string  `json:"timing"`
+	TriggerEvent  string  `json:"trigger_event"`
+	RuleReference string  `json:"rule_reference"`
+	Confidence    float64 `json:"confidence"`
+	SourceQuote   string  `json:"source_quote"`
+}
+
+type extractDeadlinesToolInput struct {
+	Deadlines []ExtractedDeadline `json:"deadlines"`
+}
+
+var deadlineExtractionTool = anthropic.ToolParam{
+	Name:        "extract_deadlines",
+	Description: anthropic.String("Extract all legal deadlines found in the document. Return each deadline with its details."),
+	InputSchema: anthropic.ToolInputSchemaParam{
+		Properties: map[string]any{
+			"deadlines": map[string]any{
+				"type":        "array",
+				"description": "List of extracted deadlines",
+				"items": map[string]any{
+					"type": "object",
+					"properties": map[string]any{
+						"title": map[string]any{
+							"type":        "string",
+							"description": "Short title describing the deadline (e.g. 'Statement of Defence', 'Reply to Counterclaim')",
+						},
+						"due_date": map[string]any{
+							"type":        []string{"string", "null"},
+							"description": "Absolute due date in YYYY-MM-DD format if determinable, null otherwise",
+						},
+						"duration_value": map[string]any{
+							"type":        "integer",
+							"description": "Numeric duration value (e.g. 3 for '3 months')",
+						},
+						"duration_unit": map[string]any{
+							"type":        "string",
+							"enum":        []string{"days", "weeks", "months"},
+							"description": "Unit of the duration period",
+						},
+						"timing": map[string]any{
+							"type":        "string",
+							"enum":        []string{"after", "before"},
+							"description": "Whether the deadline is before or after the trigger event",
+						},
+						"trigger_event": map[string]any{
+							"type":        "string",
+							"description": "The event that triggers this deadline (e.g. 'service of the Statement of Claim')",
+						},
+						"rule_reference": map[string]any{
+							"type":        "string",
+							"description": "Legal rule reference (e.g. 'Rule 23 RoP', 'Rule 222 RoP', '§ 276 ZPO')",
+						},
+						"confidence": map[string]any{
+							"type":        "number",
+							"minimum":     0,
+							"maximum":     1,
+							"description": "Confidence score from 0.0 to 1.0",
+						},
+						"source_quote": map[string]any{
+							"type":        "string",
+							"description": "The exact quote from the document where this deadline was found",
+						},
+					},
+					"required": []string{"title", "duration_value", "duration_unit", "timing", "trigger_event", "rule_reference", "confidence", "source_quote"},
+				},
+			},
+		},
+		Required: []string{"deadlines"},
+	},
+}
+
+const extractionSystemPrompt = `You are a legal deadline extraction assistant for German and UPC (Unified Patent Court) patent litigation.
+
+Your task is to extract all legal deadlines, time limits, and procedural time periods from the provided document.
+
+For each deadline found, extract:
+- A clear title describing the deadline
+- The absolute due date if it can be determined from the document
+- The duration (value + unit: days/weeks/months)
+- Whether it runs before or after a trigger event
+- The trigger event that starts the deadline
+- The legal rule reference (e.g. Rule 23 RoP, § 276 ZPO)
+- Your confidence level (0.0-1.0) in the extraction
+- The exact source quote from the document
+
+Be thorough: extract every deadline mentioned, including conditional ones. If a deadline references another deadline (e.g. "within 2 months of the defence"), capture that relationship in the trigger_event field.
+
+If the document contains no deadlines, return an empty list.`
+
+// ExtractDeadlines sends a document (PDF or text) to Claude for deadline extraction.
+func (s *AIService) ExtractDeadlines(ctx context.Context, pdfData []byte, text string) ([]ExtractedDeadline, error) {
+	var contentBlocks []anthropic.ContentBlockParamUnion
+
+	if len(pdfData) > 0 {
+		encoded := base64.StdEncoding.EncodeToString(pdfData)
+		contentBlocks = append(contentBlocks, anthropic.ContentBlockParamUnion{
+			OfDocument: &anthropic.DocumentBlockParam{
+				Source: anthropic.DocumentBlockParamSourceUnion{
+					OfBase64: &anthropic.Base64PDFSourceParam{
+						Data: encoded,
+					},
+				},
+			},
+		})
+		contentBlocks = append(contentBlocks, anthropic.NewTextBlock("Extract all legal deadlines from this document."))
+	} else if text != "" {
+		contentBlocks = append(contentBlocks, anthropic.NewTextBlock("Extract all legal deadlines from the following text:\n\n"+text))
+	} else {
+		return nil, fmt.Errorf("either pdf_data or text must be provided")
+	}
+
+	msg, err := s.client.Messages.New(ctx, anthropic.MessageNewParams{
+		Model:     anthropic.ModelClaudeSonnet4_5,
+		MaxTokens: 4096,
+		System: []anthropic.TextBlockParam{
+			{Text: extractionSystemPrompt},
+		},
+		Messages: []anthropic.MessageParam{
+			anthropic.NewUserMessage(contentBlocks...),
+		},
+		Tools: []anthropic.ToolUnionParam{
+			{OfTool: &deadlineExtractionTool},
+		},
+		ToolChoice: anthropic.ToolChoiceParamOfTool("extract_deadlines"),
+	})
+	if err != nil {
+		return nil, fmt.Errorf("claude API call: %w", err)
+	}
+
+	// Find the tool_use block in the response
+	for _, block := range msg.Content {
+		if block.Type == "tool_use" && block.Name == "extract_deadlines" {
+			var input extractDeadlinesToolInput
+			if err := json.Unmarshal(block.Input, &input); err != nil {
+				return nil, fmt.Errorf("parsing tool output: %w", err)
+			}
+			return input.Deadlines, nil
+		}
+	}
+
+	return nil, fmt.Errorf("no tool_use block in response")
+}
+
+const summarizeSystemPrompt = `You are a legal case summary assistant for German and UPC patent litigation case management.
+
+Given a case's details, recent events, and deadlines, produce a concise 2-3 sentence summary of what matters right now. Focus on:
+- The most urgent upcoming deadline
+- Recent significant events
+- The current procedural stage
+
+Write in clear, professional language suitable for a lawyer reviewing their case list. Be specific about dates and deadlines.`
+
+// SummarizeCase generates an AI summary for a case and caches it in the database.
+func (s *AIService) SummarizeCase(ctx context.Context, tenantID, caseID uuid.UUID) (string, error) {
+	// Load case
+	var c models.Case
+	err := s.db.GetContext(ctx, &c,
+		"SELECT * FROM cases WHERE id = $1 AND tenant_id = $2", caseID, tenantID)
+	if err != nil {
+		return "", fmt.Errorf("loading case: %w", err)
+	}
+
+	// Load recent events
+	var events []models.CaseEvent
+	if err := s.db.SelectContext(ctx, &events,
+		"SELECT * FROM case_events WHERE case_id = $1 AND tenant_id = $2 ORDER BY created_at DESC LIMIT 10",
+		caseID, tenantID); err != nil {
+		return "", fmt.Errorf("loading events: %w", err)
+	}
+
+	// Load active deadlines
+	var deadlines []models.Deadline
+	if err := s.db.SelectContext(ctx, &deadlines,
+		"SELECT * FROM deadlines WHERE case_id = $1 AND tenant_id = $2 AND status = 'active' ORDER BY due_date ASC LIMIT 10",
+		caseID, tenantID); err != nil {
+		return "", fmt.Errorf("loading deadlines: %w", err)
+	}
+
+	// Build context text
+	caseInfo := fmt.Sprintf("Case: %s — %s\nStatus: %s", c.CaseNumber, c.Title, c.Status)
+	if c.Court != nil {
+		caseInfo += fmt.Sprintf("\nCourt: %s", *c.Court)
+	}
+	if c.CourtRef != nil {
+		caseInfo += fmt.Sprintf("\nCourt Reference: %s", *c.CourtRef)
+	}
+	if c.CaseType != nil {
+		caseInfo += fmt.Sprintf("\nType: %s", *c.CaseType)
+	}
+
+	eventText := "\n\nRecent Events:"
+	if len(events) == 0 {
+		eventText += "\nNo events recorded."
+	}
+	for _, e := range events {
+		eventText += fmt.Sprintf("\n- [%s] %s", e.CreatedAt.Format("2006-01-02"), e.Title)
+		if e.Description != nil {
+			eventText += fmt.Sprintf(": %s", *e.Description)
+		}
+	}
+
+	deadlineText := "\n\nUpcoming Deadlines:"
+	if len(deadlines) == 0 {
+		deadlineText += "\nNo active deadlines."
+	}
+	for _, d := range deadlines {
+		deadlineText += fmt.Sprintf("\n- %s: due %s (status: %s)", d.Title, d.DueDate, d.Status)
+		if d.Description != nil {
+			deadlineText += fmt.Sprintf(" — %s", *d.Description)
+		}
+	}
+
+	prompt := caseInfo + eventText + deadlineText
+
+	msg, err := s.client.Messages.New(ctx, anthropic.MessageNewParams{
+		Model:     anthropic.ModelClaudeSonnet4_5,
+		MaxTokens: 512,
+		System: []anthropic.TextBlockParam{
+			{Text: summarizeSystemPrompt},
+		},
+		Messages: []anthropic.MessageParam{
+			anthropic.NewUserMessage(anthropic.NewTextBlock("Summarize the current state of this case:\n\n" + prompt)),
+		},
+	})
+	if err != nil {
+		return "", fmt.Errorf("claude API call: %w", err)
+	}
+
+	// Extract text from response
+	var summary string
+	for _, block := range msg.Content {
+		if block.Type == "text" {
+			summary += block.Text
+		}
+	}
+
+	if summary == "" {
+		return "", fmt.Errorf("empty response from Claude")
+	}
+
+	// Cache summary in database
+	_, err = s.db.ExecContext(ctx,
+		"UPDATE cases SET ai_summary = $1, updated_at = $2 WHERE id = $3 AND tenant_id = $4",
+		summary, time.Now(), caseID, tenantID)
+	if err != nil {
+		return "", fmt.Errorf("caching summary: %w", err)
+	}
+
+	return summary, nil
+}

backend/internal/services/ai_service_test.go

@@ -0,0 +1,109 @@
+package services
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func TestDeadlineExtractionToolSchema(t *testing.T) {
+	// Verify the tool schema serializes correctly
+	data, err := json.Marshal(deadlineExtractionTool)
+	if err != nil {
+		t.Fatalf("failed to marshal tool: %v", err)
+	}
+
+	var parsed map[string]any
+	if err := json.Unmarshal(data, &parsed); err != nil {
+		t.Fatalf("failed to unmarshal tool JSON: %v", err)
+	}
+
+	if parsed["name"] != "extract_deadlines" {
+		t.Errorf("expected name 'extract_deadlines', got %v", parsed["name"])
+	}
+
+	schema, ok := parsed["input_schema"].(map[string]any)
+	if !ok {
+		t.Fatal("input_schema is not a map")
+	}
+
+	if schema["type"] != "object" {
+		t.Errorf("expected schema type 'object', got %v", schema["type"])
+	}
+
+	props, ok := schema["properties"].(map[string]any)
+	if !ok {
+		t.Fatal("properties is not a map")
+	}
+
+	deadlines, ok := props["deadlines"].(map[string]any)
+	if !ok {
+		t.Fatal("deadlines property is not a map")
+	}
+
+	if deadlines["type"] != "array" {
+		t.Errorf("expected deadlines type 'array', got %v", deadlines["type"])
+	}
+
+	items, ok := deadlines["items"].(map[string]any)
+	if !ok {
+		t.Fatal("items is not a map")
+	}
+
+	itemProps, ok := items["properties"].(map[string]any)
+	if !ok {
+		t.Fatal("item properties is not a map")
+	}
+
+	expectedFields := []string{"title", "due_date", "duration_value", "duration_unit", "timing", "trigger_event", "rule_reference", "confidence", "source_quote"}
+	for _, field := range expectedFields {
+		if _, ok := itemProps[field]; !ok {
+			t.Errorf("missing expected field %q in item properties", field)
+		}
+	}
+
+	required, ok := items["required"].([]any)
+	if !ok {
+		t.Fatal("required is not a list")
+	}
+	if len(required) != 8 {
+		t.Errorf("expected 8 required fields, got %d", len(required))
+	}
+}
+
+func TestExtractedDeadlineJSON(t *testing.T) {
+	dueDate := "2026-04-15"
+	d := ExtractedDeadline{
+		Title:         "Statement of Defence",
+		DueDate:       &dueDate,
+		DurationValue: 3,
+		DurationUnit:  "months",
+		Timing:        "after",
+		TriggerEvent:  "service of the Statement of Claim",
+		RuleReference: "Rule 23 RoP",
+		Confidence:    0.95,
+		SourceQuote:   "The defendant shall file a defence within 3 months",
+	}
+
+	data, err := json.Marshal(d)
+	if err != nil {
+		t.Fatalf("failed to marshal: %v", err)
+	}
+
+	var parsed ExtractedDeadline
+	if err := json.Unmarshal(data, &parsed); err != nil {
+		t.Fatalf("failed to unmarshal: %v", err)
+	}
+
+	if parsed.Title != d.Title {
+		t.Errorf("title mismatch: %q != %q", parsed.Title, d.Title)
+	}
+	if *parsed.DueDate != *d.DueDate {
+		t.Errorf("due_date mismatch: %q != %q", *parsed.DueDate, *d.DueDate)
+	}
+	if parsed.DurationValue != d.DurationValue {
+		t.Errorf("duration_value mismatch: %d != %d", parsed.DurationValue, d.DurationValue)
+	}
+	if parsed.Confidence != d.Confidence {
+		t.Errorf("confidence mismatch: %f != %f", parsed.Confidence, d.Confidence)
+	}
+}

backend/internal/services/appointment_service.go

@@ -0,0 +1,135 @@
+package services
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+)
+
+type AppointmentService struct {
+	db *sqlx.DB
+}
+
+func NewAppointmentService(db *sqlx.DB) *AppointmentService {
+	return &AppointmentService{db: db}
+}
+
+type AppointmentFilter struct {
+	CaseID    *uuid.UUID
+	Type      *string
+	StartFrom *time.Time
+	StartTo   *time.Time
+}
+
+func (s *AppointmentService) List(ctx context.Context, tenantID uuid.UUID, filter AppointmentFilter) ([]models.Appointment, error) {
+	query := "SELECT * FROM appointments WHERE tenant_id = $1"
+	args := []any{tenantID}
+	argN := 2
+
+	if filter.CaseID != nil {
+		query += fmt.Sprintf(" AND case_id = $%d", argN)
+		args = append(args, *filter.CaseID)
+		argN++
+	}
+	if filter.Type != nil {
+		query += fmt.Sprintf(" AND appointment_type = $%d", argN)
+		args = append(args, *filter.Type)
+		argN++
+	}
+	if filter.StartFrom != nil {
+		query += fmt.Sprintf(" AND start_at >= $%d", argN)
+		args = append(args, *filter.StartFrom)
+		argN++
+	}
+	if filter.StartTo != nil {
+		query += fmt.Sprintf(" AND start_at <= $%d", argN)
+		args = append(args, *filter.StartTo)
+		argN++
+	}
+
+	query += " ORDER BY start_at ASC"
+
+	var appointments []models.Appointment
+	if err := s.db.SelectContext(ctx, &appointments, query, args...); err != nil {
+		return nil, fmt.Errorf("listing appointments: %w", err)
+	}
+	if appointments == nil {
+		appointments = []models.Appointment{}
+	}
+	return appointments, nil
+}
+
+func (s *AppointmentService) GetByID(ctx context.Context, tenantID, id uuid.UUID) (*models.Appointment, error) {
+	var a models.Appointment
+	err := s.db.GetContext(ctx, &a, "SELECT * FROM appointments WHERE id = $1 AND tenant_id = $2", id, tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("getting appointment: %w", err)
+	}
+	return &a, nil
+}
+
+func (s *AppointmentService) Create(ctx context.Context, a *models.Appointment) error {
+	a.ID = uuid.New()
+	now := time.Now().UTC()
+	a.CreatedAt = now
+	a.UpdatedAt = now
+
+	_, err := s.db.NamedExecContext(ctx, `
+		INSERT INTO appointments (id, tenant_id, case_id, title, description, start_at, end_at, location, appointment_type, caldav_uid, caldav_etag, created_at, updated_at)
+		VALUES (:id, :tenant_id, :case_id, :title, :description, :start_at, :end_at, :location, :appointment_type, :caldav_uid, :caldav_etag, :created_at, :updated_at)
+	`, a)
+	if err != nil {
+		return fmt.Errorf("creating appointment: %w", err)
+	}
+	return nil
+}
+
+func (s *AppointmentService) Update(ctx context.Context, a *models.Appointment) error {
+	a.UpdatedAt = time.Now().UTC()
+
+	result, err := s.db.NamedExecContext(ctx, `
+		UPDATE appointments SET
+			case_id = :case_id,
+			title = :title,
+			description = :description,
+			start_at = :start_at,
+			end_at = :end_at,
+			location = :location,
+			appointment_type = :appointment_type,
+			caldav_uid = :caldav_uid,
+			caldav_etag = :caldav_etag,
+			updated_at = :updated_at
+		WHERE id = :id AND tenant_id = :tenant_id
+	`, a)
+	if err != nil {
+		return fmt.Errorf("updating appointment: %w", err)
+	}
+	rows, err := result.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("checking rows affected: %w", err)
+	}
+	if rows == 0 {
+		return fmt.Errorf("appointment not found")
+	}
+	return nil
+}
+
+func (s *AppointmentService) Delete(ctx context.Context, tenantID, id uuid.UUID) error {
+	result, err := s.db.ExecContext(ctx, "DELETE FROM appointments WHERE id = $1 AND tenant_id = $2", id, tenantID)
+	if err != nil {
+		return fmt.Errorf("deleting appointment: %w", err)
+	}
+	rows, err := result.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("checking rows affected: %w", err)
+	}
+	if rows == 0 {
+		return fmt.Errorf("appointment not found")
+	}
+	return nil
+}

backend/internal/services/case_service.go

@@ -0,0 +1,277 @@
+package services
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+)
+
+type CaseService struct {
+	db *sqlx.DB
+}
+
+func NewCaseService(db *sqlx.DB) *CaseService {
+	return &CaseService{db: db}
+}
+
+type CaseFilter struct {
+	Status string
+	Type   string
+	Search string
+	Limit  int
+	Offset int
+}
+
+type CaseDetail struct {
+	models.Case
+	Parties        []models.Party     `json:"parties"`
+	RecentEvents   []models.CaseEvent `json:"recent_events"`
+	DeadlinesCount int                `json:"deadlines_count"`
+}
+
+type CreateCaseInput struct {
+	CaseNumber string  `json:"case_number"`
+	Title      string  `json:"title"`
+	CaseType   *string `json:"case_type,omitempty"`
+	Court      *string `json:"court,omitempty"`
+	CourtRef   *string `json:"court_ref,omitempty"`
+	Status     string  `json:"status"`
+}
+
+type UpdateCaseInput struct {
+	CaseNumber *string `json:"case_number,omitempty"`
+	Title      *string `json:"title,omitempty"`
+	CaseType   *string `json:"case_type,omitempty"`
+	Court      *string `json:"court,omitempty"`
+	CourtRef   *string `json:"court_ref,omitempty"`
+	Status     *string `json:"status,omitempty"`
+}
+
+func (s *CaseService) List(ctx context.Context, tenantID uuid.UUID, filter CaseFilter) ([]models.Case, int, error) {
+	if filter.Limit <= 0 {
+		filter.Limit = 20
+	}
+	if filter.Limit > 100 {
+		filter.Limit = 100
+	}
+
+	// Build WHERE clause
+	where := "WHERE tenant_id = $1"
+	args := []interface{}{tenantID}
+	argIdx := 2
+
+	if filter.Status != "" {
+		where += fmt.Sprintf(" AND status = $%d", argIdx)
+		args = append(args, filter.Status)
+		argIdx++
+	}
+	if filter.Type != "" {
+		where += fmt.Sprintf(" AND case_type = $%d", argIdx)
+		args = append(args, filter.Type)
+		argIdx++
+	}
+	if filter.Search != "" {
+		where += fmt.Sprintf(" AND (title ILIKE $%d OR case_number ILIKE $%d)", argIdx, argIdx)
+		args = append(args, "%"+filter.Search+"%")
+		argIdx++
+	}
+
+	// Count total
+	var total int
+	countQuery := "SELECT COUNT(*) FROM cases " + where
+	if err := s.db.GetContext(ctx, &total, countQuery, args...); err != nil {
+		return nil, 0, fmt.Errorf("counting cases: %w", err)
+	}
+
+	// Fetch page
+	query := fmt.Sprintf("SELECT * FROM cases %s ORDER BY updated_at DESC LIMIT $%d OFFSET $%d",
+		where, argIdx, argIdx+1)
+	args = append(args, filter.Limit, filter.Offset)
+
+	var cases []models.Case
+	if err := s.db.SelectContext(ctx, &cases, query, args...); err != nil {
+		return nil, 0, fmt.Errorf("listing cases: %w", err)
+	}
+
+	return cases, total, nil
+}
+
+func (s *CaseService) GetByID(ctx context.Context, tenantID, caseID uuid.UUID) (*CaseDetail, error) {
+	var c models.Case
+	err := s.db.GetContext(ctx, &c,
+		"SELECT * FROM cases WHERE id = $1 AND tenant_id = $2", caseID, tenantID)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("getting case: %w", err)
+	}
+
+	detail := &CaseDetail{Case: c}
+
+	// Parties
+	if err := s.db.SelectContext(ctx, &detail.Parties,
+		"SELECT * FROM parties WHERE case_id = $1 AND tenant_id = $2 ORDER BY name",
+		caseID, tenantID); err != nil {
+		return nil, fmt.Errorf("getting parties: %w", err)
+	}
+
+	// Recent events (last 20)
+	if err := s.db.SelectContext(ctx, &detail.RecentEvents,
+		"SELECT * FROM case_events WHERE case_id = $1 AND tenant_id = $2 ORDER BY created_at DESC LIMIT 20",
+		caseID, tenantID); err != nil {
+		return nil, fmt.Errorf("getting events: %w", err)
+	}
+
+	// Deadlines count
+	if err := s.db.GetContext(ctx, &detail.DeadlinesCount,
+		"SELECT COUNT(*) FROM deadlines WHERE case_id = $1 AND tenant_id = $2",
+		caseID, tenantID); err != nil {
+		return nil, fmt.Errorf("counting deadlines: %w", err)
+	}
+
+	return detail, nil
+}
+
+func (s *CaseService) Create(ctx context.Context, tenantID uuid.UUID, userID uuid.UUID, input CreateCaseInput) (*models.Case, error) {
+	if input.Status == "" {
+		input.Status = "active"
+	}
+
+	id := uuid.New()
+	now := time.Now()
+
+	_, err := s.db.ExecContext(ctx,
+		`INSERT INTO cases (id, tenant_id, case_number, title, case_type, court, court_ref, status, metadata, created_at, updated_at)
+		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, '{}', $9, $9)`,
+		id, tenantID, input.CaseNumber, input.Title, input.CaseType, input.Court, input.CourtRef, input.Status, now)
+	if err != nil {
+		return nil, fmt.Errorf("creating case: %w", err)
+	}
+
+	// Create case_created event
+	createEvent(ctx, s.db, tenantID, id, userID, "case_created", "Case created", nil)
+
+	var c models.Case
+	if err := s.db.GetContext(ctx, &c, "SELECT * FROM cases WHERE id = $1", id); err != nil {
+		return nil, fmt.Errorf("fetching created case: %w", err)
+	}
+	return &c, nil
+}
+
+func (s *CaseService) Update(ctx context.Context, tenantID, caseID uuid.UUID, userID uuid.UUID, input UpdateCaseInput) (*models.Case, error) {
+	// Fetch current to detect status change
+	var current models.Case
+	err := s.db.GetContext(ctx, &current,
+		"SELECT * FROM cases WHERE id = $1 AND tenant_id = $2", caseID, tenantID)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("fetching case for update: %w", err)
+	}
+
+	// Build SET clause dynamically
+	sets := []string{}
+	args := []interface{}{}
+	argIdx := 1
+
+	if input.CaseNumber != nil {
+		sets = append(sets, fmt.Sprintf("case_number = $%d", argIdx))
+		args = append(args, *input.CaseNumber)
+		argIdx++
+	}
+	if input.Title != nil {
+		sets = append(sets, fmt.Sprintf("title = $%d", argIdx))
+		args = append(args, *input.Title)
+		argIdx++
+	}
+	if input.CaseType != nil {
+		sets = append(sets, fmt.Sprintf("case_type = $%d", argIdx))
+		args = append(args, *input.CaseType)
+		argIdx++
+	}
+	if input.Court != nil {
+		sets = append(sets, fmt.Sprintf("court = $%d", argIdx))
+		args = append(args, *input.Court)
+		argIdx++
+	}
+	if input.CourtRef != nil {
+		sets = append(sets, fmt.Sprintf("court_ref = $%d", argIdx))
+		args = append(args, *input.CourtRef)
+		argIdx++
+	}
+	if input.Status != nil {
+		sets = append(sets, fmt.Sprintf("status = $%d", argIdx))
+		args = append(args, *input.Status)
+		argIdx++
+	}
+
+	if len(sets) == 0 {
+		return &current, nil
+	}
+
+	sets = append(sets, fmt.Sprintf("updated_at = $%d", argIdx))
+	args = append(args, time.Now())
+	argIdx++
+
+	query := fmt.Sprintf("UPDATE cases SET %s WHERE id = $%d AND tenant_id = $%d",
+		joinStrings(sets, ", "), argIdx, argIdx+1)
+	args = append(args, caseID, tenantID)
+
+	if _, err := s.db.ExecContext(ctx, query, args...); err != nil {
+		return nil, fmt.Errorf("updating case: %w", err)
+	}
+
+	// Log status change event
+	if input.Status != nil && *input.Status != current.Status {
+		desc := fmt.Sprintf("Status changed from %s to %s", current.Status, *input.Status)
+		createEvent(ctx, s.db, tenantID, caseID, userID, "status_changed", desc, nil)
+	}
+
+	var updated models.Case
+	if err := s.db.GetContext(ctx, &updated, "SELECT * FROM cases WHERE id = $1", caseID); err != nil {
+		return nil, fmt.Errorf("fetching updated case: %w", err)
+	}
+	return &updated, nil
+}
+
+func (s *CaseService) Delete(ctx context.Context, tenantID, caseID uuid.UUID, userID uuid.UUID) error {
+	result, err := s.db.ExecContext(ctx,
+		"UPDATE cases SET status = 'archived', updated_at = $1 WHERE id = $2 AND tenant_id = $3 AND status != 'archived'",
+		time.Now(), caseID, tenantID)
+	if err != nil {
+		return fmt.Errorf("archiving case: %w", err)
+	}
+	rows, _ := result.RowsAffected()
+	if rows == 0 {
+		return sql.ErrNoRows
+	}
+	createEvent(ctx, s.db, tenantID, caseID, userID, "case_archived", "Case archived", nil)
+	return nil
+}
+
+func createEvent(ctx context.Context, db *sqlx.DB, tenantID, caseID uuid.UUID, userID uuid.UUID, eventType, title string, description *string) {
+	now := time.Now()
+	db.ExecContext(ctx,
+		`INSERT INTO case_events (id, tenant_id, case_id, event_type, title, description, event_date, created_by, metadata, created_at, updated_at)
+		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, '{}', $7, $7)`,
+		uuid.New(), tenantID, caseID, eventType, title, description, now, userID)
+}
+
+func joinStrings(strs []string, sep string) string {
+	result := ""
+	for i, s := range strs {
+		if i > 0 {
+			result += sep
+		}
+		result += s
+	}
+	return result
+}

backend/internal/services/dashboard_service.go

@@ -0,0 +1,151 @@
+package services
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+)
+
+type DashboardService struct {
+	db *sqlx.DB
+}
+
+func NewDashboardService(db *sqlx.DB) *DashboardService {
+	return &DashboardService{db: db}
+}
+
+type DashboardData struct {
+	DeadlineSummary      DeadlineSummary       `json:"deadline_summary"`
+	CaseSummary          CaseSummary           `json:"case_summary"`
+	UpcomingDeadlines    []UpcomingDeadline    `json:"upcoming_deadlines"`
+	UpcomingAppointments []UpcomingAppointment `json:"upcoming_appointments"`
+	RecentActivity       []RecentActivity      `json:"recent_activity"`
+}
+
+type DeadlineSummary struct {
+	OverdueCount int `json:"overdue_count" db:"overdue_count"`
+	DueThisWeek  int `json:"due_this_week" db:"due_this_week"`
+	DueNextWeek  int `json:"due_next_week" db:"due_next_week"`
+	OKCount      int `json:"ok_count" db:"ok_count"`
+}
+
+type CaseSummary struct {
+	ActiveCount  int `json:"active_count" db:"active_count"`
+	NewThisMonth int `json:"new_this_month" db:"new_this_month"`
+	ClosedCount  int `json:"closed_count" db:"closed_count"`
+}
+
+type UpcomingDeadline struct {
+	ID         uuid.UUID `json:"id" db:"id"`
+	Title      string    `json:"title" db:"title"`
+	DueDate    string    `json:"due_date" db:"due_date"`
+	CaseNumber string    `json:"case_number" db:"case_number"`
+	CaseTitle  string    `json:"case_title" db:"case_title"`
+	Status     string    `json:"status" db:"status"`
+}
+
+type UpcomingAppointment struct {
+	ID         uuid.UUID  `json:"id" db:"id"`
+	Title      string     `json:"title" db:"title"`
+	StartAt    time.Time  `json:"start_at" db:"start_at"`
+	CaseNumber *string    `json:"case_number" db:"case_number"`
+	Location   *string    `json:"location" db:"location"`
+}
+
+type RecentActivity struct {
+	EventType  *string    `json:"event_type" db:"event_type"`
+	Title      string     `json:"title" db:"title"`
+	CaseNumber string     `json:"case_number" db:"case_number"`
+	EventDate  *time.Time `json:"event_date" db:"event_date"`
+}
+
+func (s *DashboardService) Get(ctx context.Context, tenantID uuid.UUID) (*DashboardData, error) {
+	now := time.Now()
+	today := now.Format("2006-01-02")
+	endOfWeek := now.AddDate(0, 0, 7-int(now.Weekday())).Format("2006-01-02")
+	endOfNextWeek := now.AddDate(0, 0, 14-int(now.Weekday())).Format("2006-01-02")
+	in7Days := now.AddDate(0, 0, 7).Format("2006-01-02")
+	startOfMonth := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location()).Format("2006-01-02")
+
+	data := &DashboardData{}
+
+	// Single query with CTEs for deadline + case summaries
+	summaryQuery := `
+		WITH deadline_stats AS (
+			SELECT
+				COUNT(*) FILTER (WHERE due_date < $2 AND status = 'pending') AS overdue_count,
+				COUNT(*) FILTER (WHERE due_date >= $2 AND due_date <= $3 AND status = 'pending') AS due_this_week,
+				COUNT(*) FILTER (WHERE due_date > $3 AND due_date <= $4 AND status = 'pending') AS due_next_week,
+				COUNT(*) FILTER (WHERE due_date > $4 AND status = 'pending') AS ok_count
+			FROM deadlines
+			WHERE tenant_id = $1
+		),
+		case_stats AS (
+			SELECT
+				COUNT(*) FILTER (WHERE status = 'active') AS active_count,
+				COUNT(*) FILTER (WHERE created_at >= $5::date AND status != 'archived') AS new_this_month,
+				COUNT(*) FILTER (WHERE status IN ('closed', 'archived')) AS closed_count
+			FROM cases
+			WHERE tenant_id = $1
+		)
+		SELECT
+			ds.overdue_count, ds.due_this_week, ds.due_next_week, ds.ok_count,
+			cs.active_count, cs.new_this_month, cs.closed_count
+		FROM deadline_stats ds, case_stats cs`
+
+	var summaryRow struct {
+		DeadlineSummary
+		CaseSummary
+	}
+	err := s.db.GetContext(ctx, &summaryRow, summaryQuery, tenantID, today, endOfWeek, endOfNextWeek, startOfMonth)
+	if err != nil {
+		return nil, fmt.Errorf("dashboard summary: %w", err)
+	}
+	data.DeadlineSummary = summaryRow.DeadlineSummary
+	data.CaseSummary = summaryRow.CaseSummary
+
+	// Upcoming deadlines (next 7 days)
+	deadlineQuery := `
+		SELECT d.id, d.title, d.due_date, c.case_number, c.title AS case_title, d.status
+		FROM deadlines d
+		JOIN cases c ON c.id = d.case_id AND c.tenant_id = d.tenant_id
+		WHERE d.tenant_id = $1 AND d.status = 'pending' AND d.due_date >= $2 AND d.due_date <= $3
+		ORDER BY d.due_date ASC`
+
+	data.UpcomingDeadlines = []UpcomingDeadline{}
+	if err := s.db.SelectContext(ctx, &data.UpcomingDeadlines, deadlineQuery, tenantID, today, in7Days); err != nil {
+		return nil, fmt.Errorf("dashboard upcoming deadlines: %w", err)
+	}
+
+	// Upcoming appointments (next 7 days)
+	appointmentQuery := `
+		SELECT a.id, a.title, a.start_at, c.case_number, a.location
+		FROM appointments a
+		LEFT JOIN cases c ON c.id = a.case_id AND c.tenant_id = a.tenant_id
+		WHERE a.tenant_id = $1 AND a.start_at >= $2::timestamp AND a.start_at < ($2::date + interval '7 days')
+		ORDER BY a.start_at ASC`
+
+	data.UpcomingAppointments = []UpcomingAppointment{}
+	if err := s.db.SelectContext(ctx, &data.UpcomingAppointments, appointmentQuery, tenantID, now); err != nil {
+		return nil, fmt.Errorf("dashboard upcoming appointments: %w", err)
+	}
+
+	// Recent activity (last 10 case events)
+	activityQuery := `
+		SELECT ce.event_type, ce.title, c.case_number, ce.event_date
+		FROM case_events ce
+		JOIN cases c ON c.id = ce.case_id AND c.tenant_id = ce.tenant_id
+		WHERE ce.tenant_id = $1
+		ORDER BY COALESCE(ce.event_date, ce.created_at) DESC
+		LIMIT 10`
+
+	data.RecentActivity = []RecentActivity{}
+	if err := s.db.SelectContext(ctx, &data.RecentActivity, activityQuery, tenantID); err != nil {
+		return nil, fmt.Errorf("dashboard recent activity: %w", err)
+	}
+
+	return data, nil
+}

backend/internal/services/dashboard_service_test.go

@@ -0,0 +1,33 @@
+package services
+
+import (
+	"testing"
+	"time"
+)
+
+func TestDashboardDateCalculations(t *testing.T) {
+	// Verify the date range logic used in Get()
+	now := time.Date(2026, 3, 25, 14, 0, 0, 0, time.UTC) // Wednesday
+
+	today := now.Format("2006-01-02")
+	endOfWeek := now.AddDate(0, 0, 7-int(now.Weekday())).Format("2006-01-02")
+	endOfNextWeek := now.AddDate(0, 0, 14-int(now.Weekday())).Format("2006-01-02")
+	in7Days := now.AddDate(0, 0, 7).Format("2006-01-02")
+	startOfMonth := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location()).Format("2006-01-02")
+
+	if today != "2026-03-25" {
+		t.Errorf("today = %s, want 2026-03-25", today)
+	}
+	if endOfWeek != "2026-03-29" { // Sunday
+		t.Errorf("endOfWeek = %s, want 2026-03-29", endOfWeek)
+	}
+	if endOfNextWeek != "2026-04-05" {
+		t.Errorf("endOfNextWeek = %s, want 2026-04-05", endOfNextWeek)
+	}
+	if in7Days != "2026-04-01" {
+		t.Errorf("in7Days = %s, want 2026-04-01", in7Days)
+	}
+	if startOfMonth != "2026-03-01" {
+		t.Errorf("startOfMonth = %s, want 2026-03-01", startOfMonth)
+	}
+}

backend/internal/services/deadline_calculator.go

@@ -0,0 +1,99 @@
+package services
+
+import (
+	"time"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+)
+
+// CalculatedDeadline holds a calculated deadline with adjustment info
+type CalculatedDeadline struct {
+	RuleCode        string `json:"rule_code"`
+	RuleID          string `json:"rule_id"`
+	Title           string `json:"title"`
+	DueDate         string `json:"due_date"`
+	OriginalDueDate string `json:"original_due_date"`
+	WasAdjusted     bool   `json:"was_adjusted"`
+}
+
+// DeadlineCalculator calculates deadlines from rules and event dates
+type DeadlineCalculator struct {
+	holidays *HolidayService
+}
+
+// NewDeadlineCalculator creates a new calculator
+func NewDeadlineCalculator(holidays *HolidayService) *DeadlineCalculator {
+	return &DeadlineCalculator{holidays: holidays}
+}
+
+// CalculateEndDate calculates the end date for a single deadline rule based on an event date.
+// Adapted from youpc.org CalculateDeadlineEndDate.
+func (c *DeadlineCalculator) CalculateEndDate(eventDate time.Time, rule models.DeadlineRule) (adjusted time.Time, original time.Time, wasAdjusted bool) {
+	endDate := eventDate
+
+	timing := "after"
+	if rule.Timing != nil {
+		timing = *rule.Timing
+	}
+
+	durationValue := rule.DurationValue
+	durationUnit := rule.DurationUnit
+
+	if timing == "before" {
+		switch durationUnit {
+		case "days":
+			endDate = endDate.AddDate(0, 0, -durationValue)
+		case "weeks":
+			endDate = endDate.AddDate(0, 0, -durationValue*7)
+		case "months":
+			endDate = endDate.AddDate(0, -durationValue, 0)
+		}
+	} else {
+		switch durationUnit {
+		case "days":
+			endDate = endDate.AddDate(0, 0, durationValue)
+		case "weeks":
+			endDate = endDate.AddDate(0, 0, durationValue*7)
+		case "months":
+			endDate = endDate.AddDate(0, durationValue, 0)
+		}
+	}
+
+	original = endDate
+	adjusted, _, wasAdjusted = c.holidays.AdjustForNonWorkingDays(endDate)
+	return adjusted, original, wasAdjusted
+}
+
+// CalculateFromRules calculates deadlines for a set of rules given an event date.
+// Returns a list of calculated deadlines with due dates.
+func (c *DeadlineCalculator) CalculateFromRules(eventDate time.Time, rules []models.DeadlineRule) []CalculatedDeadline {
+	results := make([]CalculatedDeadline, 0, len(rules))
+
+	for _, rule := range rules {
+		var adjusted, original time.Time
+		var wasAdjusted bool
+
+		if rule.DurationValue > 0 {
+			adjusted, original, wasAdjusted = c.CalculateEndDate(eventDate, rule)
+		} else {
+			adjusted = eventDate
+			original = eventDate
+		}
+
+		code := ""
+		if rule.Code != nil {
+			code = *rule.Code
+		}
+
+		results = append(results, CalculatedDeadline{
+			RuleCode:        code,
+			RuleID:          rule.ID.String(),
+			Title:           rule.Name,
+			DueDate:         adjusted.Format("2006-01-02"),
+			OriginalDueDate: original.Format("2006-01-02"),
+			WasAdjusted:     wasAdjusted,
+		})
+	}
+
+	return results
+}

backend/internal/services/deadline_calculator_test.go

@@ -0,0 +1,141 @@
+package services
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+)
+
+func TestCalculateEndDateAfterDays(t *testing.T) {
+	holidays := NewHolidayService(nil)
+	calc := NewDeadlineCalculator(holidays)
+
+	eventDate := time.Date(2026, 3, 25, 0, 0, 0, 0, time.UTC) // Wednesday
+	timing := "after"
+	rule := models.DeadlineRule{
+		ID:            uuid.New(),
+		Name:          "Test 10 days",
+		DurationValue: 10,
+		DurationUnit:  "days",
+		Timing:        &timing,
+	}
+
+	adjusted, original, wasAdjusted := calc.CalculateEndDate(eventDate, rule)
+
+	// 25 March + 10 days = 4 April 2026 (Saturday)
+	// Apr 5 = Easter Sunday (holiday), Apr 6 = Easter Monday (holiday) -> adjusted to 7 April (Tuesday)
+	expectedOriginal := time.Date(2026, 4, 4, 0, 0, 0, 0, time.UTC)
+	expectedAdjusted := time.Date(2026, 4, 7, 0, 0, 0, 0, time.UTC)
+
+	if original != expectedOriginal {
+		t.Errorf("original should be %s, got %s", expectedOriginal, original)
+	}
+	if adjusted != expectedAdjusted {
+		t.Errorf("adjusted should be %s, got %s", expectedAdjusted, adjusted)
+	}
+	if !wasAdjusted {
+		t.Error("should have been adjusted (Saturday)")
+	}
+}
+
+func TestCalculateEndDateBeforeMonths(t *testing.T) {
+	holidays := NewHolidayService(nil)
+	calc := NewDeadlineCalculator(holidays)
+
+	eventDate := time.Date(2026, 6, 15, 0, 0, 0, 0, time.UTC) // Monday
+	timing := "before"
+	rule := models.DeadlineRule{
+		ID:            uuid.New(),
+		Name:          "Test 2 months before",
+		DurationValue: 2,
+		DurationUnit:  "months",
+		Timing:        &timing,
+	}
+
+	adjusted, original, wasAdjusted := calc.CalculateEndDate(eventDate, rule)
+
+	// 15 June - 2 months = 15 April 2026 (Wednesday)
+	expected := time.Date(2026, 4, 15, 0, 0, 0, 0, time.UTC)
+
+	if original != expected {
+		t.Errorf("original should be %s, got %s", expected, original)
+	}
+	if adjusted != expected {
+		t.Errorf("adjusted should be %s (not a holiday/weekend), got %s", expected, adjusted)
+	}
+	if wasAdjusted {
+		t.Error("should not have been adjusted (Wednesday)")
+	}
+}
+
+func TestCalculateEndDateWeeks(t *testing.T) {
+	holidays := NewHolidayService(nil)
+	calc := NewDeadlineCalculator(holidays)
+
+	eventDate := time.Date(2026, 3, 25, 0, 0, 0, 0, time.UTC) // Wednesday
+	timing := "after"
+	rule := models.DeadlineRule{
+		ID:            uuid.New(),
+		Name:          "Test 2 weeks",
+		DurationValue: 2,
+		DurationUnit:  "weeks",
+		Timing:        &timing,
+	}
+
+	adjusted, original, _ := calc.CalculateEndDate(eventDate, rule)
+
+	// 25 March + 14 days = 8 April 2026 (Wednesday)
+	expected := time.Date(2026, 4, 8, 0, 0, 0, 0, time.UTC)
+	if original != expected {
+		t.Errorf("original should be %s, got %s", expected, original)
+	}
+	if adjusted != expected {
+		t.Errorf("adjusted should be %s, got %s", expected, adjusted)
+	}
+}
+
+func TestCalculateFromRules(t *testing.T) {
+	holidays := NewHolidayService(nil)
+	calc := NewDeadlineCalculator(holidays)
+
+	eventDate := time.Date(2026, 3, 25, 0, 0, 0, 0, time.UTC)
+	timing := "after"
+	code := "TEST-1"
+
+	rules := []models.DeadlineRule{
+		{
+			ID:            uuid.New(),
+			Code:          &code,
+			Name:          "Rule A",
+			DurationValue: 7,
+			DurationUnit:  "days",
+			Timing:        &timing,
+		},
+		{
+			ID:            uuid.New(),
+			Name:          "Rule B (zero duration)",
+			DurationValue: 0,
+			DurationUnit:  "days",
+		},
+	}
+
+	results := calc.CalculateFromRules(eventDate, rules)
+	if len(results) != 2 {
+		t.Fatalf("expected 2 results, got %d", len(results))
+	}
+
+	// Rule A: 25 March + 7 = 1 April (Wednesday)
+	if results[0].DueDate != "2026-04-01" {
+		t.Errorf("Rule A due date should be 2026-04-01, got %s", results[0].DueDate)
+	}
+	if results[0].RuleCode != "TEST-1" {
+		t.Errorf("Rule A code should be TEST-1, got %s", results[0].RuleCode)
+	}
+
+	// Rule B: zero duration -> event date
+	if results[1].DueDate != "2026-03-25" {
+		t.Errorf("Rule B due date should be 2026-03-25, got %s", results[1].DueDate)
+	}
+}

backend/internal/services/deadline_rule_service.go

@@ -0,0 +1,175 @@
+package services
+
+import (
+	"fmt"
+
+	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+)
+
+// DeadlineRuleService handles deadline rule queries
+type DeadlineRuleService struct {
+	db *sqlx.DB
+}
+
+// NewDeadlineRuleService creates a new deadline rule service
+func NewDeadlineRuleService(db *sqlx.DB) *DeadlineRuleService {
+	return &DeadlineRuleService{db: db}
+}
+
+// List returns deadline rules, optionally filtered by proceeding type
+func (s *DeadlineRuleService) List(proceedingTypeID *int) ([]models.DeadlineRule, error) {
+	var rules []models.DeadlineRule
+	var err error
+
+	if proceedingTypeID != nil {
+		err = s.db.Select(&rules,
+			`SELECT id, proceeding_type_id, parent_id, code, name, description,
+			        primary_party, event_type, is_mandatory, duration_value, duration_unit,
+			        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
+			        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
+			        created_at, updated_at
+			 FROM deadline_rules
+			 WHERE proceeding_type_id = $1 AND is_active = true
+			 ORDER BY sequence_order`, *proceedingTypeID)
+	} else {
+		err = s.db.Select(&rules,
+			`SELECT id, proceeding_type_id, parent_id, code, name, description,
+			        primary_party, event_type, is_mandatory, duration_value, duration_unit,
+			        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
+			        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
+			        created_at, updated_at
+			 FROM deadline_rules
+			 WHERE is_active = true
+			 ORDER BY proceeding_type_id, sequence_order`)
+	}
+
+	if err != nil {
+		return nil, fmt.Errorf("listing deadline rules: %w", err)
+	}
+	return rules, nil
+}
+
+// RuleTreeNode represents a deadline rule with its children
+type RuleTreeNode struct {
+	models.DeadlineRule
+	Children []RuleTreeNode `json:"children,omitempty"`
+}
+
+// GetRuleTree returns a hierarchical tree of rules for a proceeding type
+func (s *DeadlineRuleService) GetRuleTree(proceedingTypeCode string) ([]RuleTreeNode, error) {
+	// First resolve proceeding type code to ID
+	var pt models.ProceedingType
+	err := s.db.Get(&pt,
+		`SELECT id, code, name, description, jurisdiction, default_color, sort_order, is_active
+		 FROM proceeding_types
+		 WHERE code = $1 AND is_active = true`, proceedingTypeCode)
+	if err != nil {
+		return nil, fmt.Errorf("resolving proceeding type %q: %w", proceedingTypeCode, err)
+	}
+
+	// Get all rules for this proceeding type
+	var rules []models.DeadlineRule
+	err = s.db.Select(&rules,
+		`SELECT id, proceeding_type_id, parent_id, code, name, description,
+		        primary_party, event_type, is_mandatory, duration_value, duration_unit,
+		        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
+		        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
+		        created_at, updated_at
+		 FROM deadline_rules
+		 WHERE proceeding_type_id = $1 AND is_active = true
+		 ORDER BY sequence_order`, pt.ID)
+	if err != nil {
+		return nil, fmt.Errorf("listing rules for type %q: %w", proceedingTypeCode, err)
+	}
+
+	return buildTree(rules), nil
+}
+
+// GetByIDs returns deadline rules by their IDs
+func (s *DeadlineRuleService) GetByIDs(ids []string) ([]models.DeadlineRule, error) {
+	if len(ids) == 0 {
+		return nil, nil
+	}
+
+	query, args, err := sqlx.In(
+		`SELECT id, proceeding_type_id, parent_id, code, name, description,
+		        primary_party, event_type, is_mandatory, duration_value, duration_unit,
+		        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
+		        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
+		        created_at, updated_at
+		 FROM deadline_rules
+		 WHERE id IN (?) AND is_active = true
+		 ORDER BY sequence_order`, ids)
+	if err != nil {
+		return nil, fmt.Errorf("building IN query: %w", err)
+	}
+	query = s.db.Rebind(query)
+
+	var rules []models.DeadlineRule
+	err = s.db.Select(&rules, query, args...)
+	if err != nil {
+		return nil, fmt.Errorf("fetching rules by IDs: %w", err)
+	}
+	return rules, nil
+}
+
+// GetRulesForProceedingType returns all active rules for a proceeding type ID
+func (s *DeadlineRuleService) GetRulesForProceedingType(proceedingTypeID int) ([]models.DeadlineRule, error) {
+	var rules []models.DeadlineRule
+	err := s.db.Select(&rules,
+		`SELECT id, proceeding_type_id, parent_id, code, name, description,
+		        primary_party, event_type, is_mandatory, duration_value, duration_unit,
+		        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
+		        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
+		        created_at, updated_at
+		 FROM deadline_rules
+		 WHERE proceeding_type_id = $1 AND is_active = true
+		 ORDER BY sequence_order`, proceedingTypeID)
+	if err != nil {
+		return nil, fmt.Errorf("listing rules for proceeding type %d: %w", proceedingTypeID, err)
+	}
+	return rules, nil
+}
+
+// ListProceedingTypes returns all active proceeding types
+func (s *DeadlineRuleService) ListProceedingTypes() ([]models.ProceedingType, error) {
+	var types []models.ProceedingType
+	err := s.db.Select(&types,
+		`SELECT id, code, name, description, jurisdiction, default_color, sort_order, is_active
+		 FROM proceeding_types
+		 WHERE is_active = true
+		 ORDER BY sort_order`)
+	if err != nil {
+		return nil, fmt.Errorf("listing proceeding types: %w", err)
+	}
+	return types, nil
+}
+
+// buildTree converts a flat list of rules into a hierarchical tree
+func buildTree(rules []models.DeadlineRule) []RuleTreeNode {
+	nodeMap := make(map[string]*RuleTreeNode, len(rules))
+	var roots []RuleTreeNode
+
+	// Create nodes
+	for _, r := range rules {
+		node := RuleTreeNode{DeadlineRule: r}
+		nodeMap[r.ID.String()] = &node
+	}
+
+	// Build tree
+	for _, r := range rules {
+		node := nodeMap[r.ID.String()]
+		if r.ParentID != nil {
+			parentKey := r.ParentID.String()
+			if parent, ok := nodeMap[parentKey]; ok {
+				parent.Children = append(parent.Children, *node)
+				continue
+			}
+		}
+		roots = append(roots, *node)
+	}
+
+	return roots
+}

backend/internal/services/deadline_service.go

@@ -0,0 +1,180 @@
+package services
+
+import (
+	"database/sql"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+)
+
+// DeadlineService handles CRUD operations for case deadlines
+type DeadlineService struct {
+	db *sqlx.DB
+}
+
+// NewDeadlineService creates a new deadline service
+func NewDeadlineService(db *sqlx.DB) *DeadlineService {
+	return &DeadlineService{db: db}
+}
+
+// ListForCase returns all deadlines for a case, scoped to tenant
+func (s *DeadlineService) ListForCase(tenantID, caseID uuid.UUID) ([]models.Deadline, error) {
+	query := `SELECT id, tenant_id, case_id, title, description, due_date, original_due_date,
+	                 warning_date, source, rule_id, status, completed_at,
+	                 caldav_uid, caldav_etag, notes, created_at, updated_at
+	          FROM deadlines
+	          WHERE tenant_id = $1 AND case_id = $2
+	          ORDER BY due_date ASC`
+
+	var deadlines []models.Deadline
+	err := s.db.Select(&deadlines, query, tenantID, caseID)
+	if err != nil {
+		return nil, fmt.Errorf("listing deadlines for case: %w", err)
+	}
+	return deadlines, nil
+}
+
+// GetByID returns a single deadline by ID, scoped to tenant
+func (s *DeadlineService) GetByID(tenantID, deadlineID uuid.UUID) (*models.Deadline, error) {
+	query := `SELECT id, tenant_id, case_id, title, description, due_date, original_due_date,
+	                 warning_date, source, rule_id, status, completed_at,
+	                 caldav_uid, caldav_etag, notes, created_at, updated_at
+	          FROM deadlines
+	          WHERE tenant_id = $1 AND id = $2`
+
+	var d models.Deadline
+	err := s.db.Get(&d, query, tenantID, deadlineID)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("getting deadline: %w", err)
+	}
+	return &d, nil
+}
+
+// CreateDeadlineInput holds the fields for creating a deadline
+type CreateDeadlineInput struct {
+	CaseID      uuid.UUID  `json:"case_id"`
+	Title       string     `json:"title"`
+	Description *string    `json:"description,omitempty"`
+	DueDate     string     `json:"due_date"`
+	WarningDate *string    `json:"warning_date,omitempty"`
+	Source      string     `json:"source"`
+	RuleID      *uuid.UUID `json:"rule_id,omitempty"`
+	Notes       *string    `json:"notes,omitempty"`
+}
+
+// Create inserts a new deadline
+func (s *DeadlineService) Create(tenantID uuid.UUID, input CreateDeadlineInput) (*models.Deadline, error) {
+	id := uuid.New()
+	source := input.Source
+	if source == "" {
+		source = "manual"
+	}
+
+	query := `INSERT INTO deadlines (id, tenant_id, case_id, title, description, due_date,
+	                                  warning_date, source, rule_id, status, notes,
+	                                  created_at, updated_at)
+	          VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, 'pending', $10, NOW(), NOW())
+	          RETURNING id, tenant_id, case_id, title, description, due_date, original_due_date,
+	                    warning_date, source, rule_id, status, completed_at,
+	                    caldav_uid, caldav_etag, notes, created_at, updated_at`
+
+	var d models.Deadline
+	err := s.db.Get(&d, query, id, tenantID, input.CaseID, input.Title, input.Description,
+		input.DueDate, input.WarningDate, source, input.RuleID, input.Notes)
+	if err != nil {
+		return nil, fmt.Errorf("creating deadline: %w", err)
+	}
+	return &d, nil
+}
+
+// UpdateDeadlineInput holds the fields for updating a deadline
+type UpdateDeadlineInput struct {
+	Title       *string    `json:"title,omitempty"`
+	Description *string    `json:"description,omitempty"`
+	DueDate     *string    `json:"due_date,omitempty"`
+	WarningDate *string    `json:"warning_date,omitempty"`
+	Notes       *string    `json:"notes,omitempty"`
+	Status      *string    `json:"status,omitempty"`
+	RuleID      *uuid.UUID `json:"rule_id,omitempty"`
+}
+
+// Update modifies an existing deadline
+func (s *DeadlineService) Update(tenantID, deadlineID uuid.UUID, input UpdateDeadlineInput) (*models.Deadline, error) {
+	// First check it exists and belongs to tenant
+	existing, err := s.GetByID(tenantID, deadlineID)
+	if err != nil {
+		return nil, err
+	}
+	if existing == nil {
+		return nil, nil
+	}
+
+	query := `UPDATE deadlines SET
+	            title = COALESCE($1, title),
+	            description = COALESCE($2, description),
+	            due_date = COALESCE($3, due_date),
+	            warning_date = COALESCE($4, warning_date),
+	            notes = COALESCE($5, notes),
+	            status = COALESCE($6, status),
+	            rule_id = COALESCE($7, rule_id),
+	            updated_at = NOW()
+	          WHERE id = $8 AND tenant_id = $9
+	          RETURNING id, tenant_id, case_id, title, description, due_date, original_due_date,
+	                    warning_date, source, rule_id, status, completed_at,
+	                    caldav_uid, caldav_etag, notes, created_at, updated_at`
+
+	var d models.Deadline
+	err = s.db.Get(&d, query, input.Title, input.Description, input.DueDate,
+		input.WarningDate, input.Notes, input.Status, input.RuleID,
+		deadlineID, tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("updating deadline: %w", err)
+	}
+	return &d, nil
+}
+
+// Complete marks a deadline as completed
+func (s *DeadlineService) Complete(tenantID, deadlineID uuid.UUID) (*models.Deadline, error) {
+	query := `UPDATE deadlines SET
+	            status = 'completed',
+	            completed_at = $1,
+	            updated_at = NOW()
+	          WHERE id = $2 AND tenant_id = $3
+	          RETURNING id, tenant_id, case_id, title, description, due_date, original_due_date,
+	                    warning_date, source, rule_id, status, completed_at,
+	                    caldav_uid, caldav_etag, notes, created_at, updated_at`
+
+	var d models.Deadline
+	err := s.db.Get(&d, query, time.Now(), deadlineID, tenantID)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("completing deadline: %w", err)
+	}
+	return &d, nil
+}
+
+// Delete removes a deadline
+func (s *DeadlineService) Delete(tenantID, deadlineID uuid.UUID) error {
+	query := `DELETE FROM deadlines WHERE id = $1 AND tenant_id = $2`
+	result, err := s.db.Exec(query, deadlineID, tenantID)
+	if err != nil {
+		return fmt.Errorf("deleting deadline: %w", err)
+	}
+	rows, err := result.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("checking delete result: %w", err)
+	}
+	if rows == 0 {
+		return fmt.Errorf("deadline not found")
+	}
+	return nil
+}

backend/internal/services/document_service.go

@@ -0,0 +1,163 @@
+package services
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"io"
+	"time"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+)
+
+const documentBucket = "kanzlai-documents"
+
+type DocumentService struct {
+	db      *sqlx.DB
+	storage *StorageClient
+}
+
+func NewDocumentService(db *sqlx.DB, storage *StorageClient) *DocumentService {
+	return &DocumentService{db: db, storage: storage}
+}
+
+type CreateDocumentInput struct {
+	Title       string `json:"title"`
+	DocType     string `json:"doc_type"`
+	Filename    string
+	ContentType string
+	Size        int
+	Data        io.Reader
+}
+
+func (s *DocumentService) ListByCase(ctx context.Context, tenantID, caseID uuid.UUID) ([]models.Document, error) {
+	var docs []models.Document
+	err := s.db.SelectContext(ctx, &docs,
+		"SELECT * FROM documents WHERE tenant_id = $1 AND case_id = $2 ORDER BY created_at DESC",
+		tenantID, caseID)
+	if err != nil {
+		return nil, fmt.Errorf("listing documents: %w", err)
+	}
+	return docs, nil
+}
+
+func (s *DocumentService) GetByID(ctx context.Context, tenantID, docID uuid.UUID) (*models.Document, error) {
+	var doc models.Document
+	err := s.db.GetContext(ctx, &doc,
+		"SELECT * FROM documents WHERE id = $1 AND tenant_id = $2", docID, tenantID)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("getting document: %w", err)
+	}
+	return &doc, nil
+}
+
+func (s *DocumentService) Create(ctx context.Context, tenantID, caseID, userID uuid.UUID, input CreateDocumentInput) (*models.Document, error) {
+	// Verify case belongs to tenant
+	var caseExists int
+	if err := s.db.GetContext(ctx, &caseExists,
+		"SELECT COUNT(*) FROM cases WHERE id = $1 AND tenant_id = $2",
+		caseID, tenantID); err != nil {
+		return nil, fmt.Errorf("verifying case: %w", err)
+	}
+	if caseExists == 0 {
+		return nil, fmt.Errorf("case not found")
+	}
+
+	id := uuid.New()
+	storagePath := fmt.Sprintf("%s/%s/%s_%s", tenantID, caseID, id, input.Filename)
+
+	// Upload to Supabase Storage
+	if err := s.storage.Upload(ctx, documentBucket, storagePath, input.ContentType, input.Data); err != nil {
+		return nil, fmt.Errorf("uploading file: %w", err)
+	}
+
+	// Insert metadata record
+	now := time.Now()
+	_, err := s.db.ExecContext(ctx,
+		`INSERT INTO documents (id, tenant_id, case_id, title, doc_type, file_path, file_size, mime_type, uploaded_by, created_at, updated_at)
+		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $10)`,
+		id, tenantID, caseID, input.Title, nilIfEmpty(input.DocType), storagePath, input.Size, input.ContentType, userID, now)
+	if err != nil {
+		// Best effort: clean up uploaded file
+		_ = s.storage.Delete(ctx, documentBucket, []string{storagePath})
+		return nil, fmt.Errorf("inserting document record: %w", err)
+	}
+
+	// Log case event
+	createEvent(ctx, s.db, tenantID, caseID, userID, "document_uploaded",
+		fmt.Sprintf("Document uploaded: %s", input.Title), nil)
+
+	var doc models.Document
+	if err := s.db.GetContext(ctx, &doc, "SELECT * FROM documents WHERE id = $1", id); err != nil {
+		return nil, fmt.Errorf("fetching created document: %w", err)
+	}
+	return &doc, nil
+}
+
+func (s *DocumentService) Download(ctx context.Context, tenantID, docID uuid.UUID) (io.ReadCloser, string, string, error) {
+	doc, err := s.GetByID(ctx, tenantID, docID)
+	if err != nil {
+		return nil, "", "", err
+	}
+	if doc == nil {
+		return nil, "", "", fmt.Errorf("document not found")
+	}
+	if doc.FilePath == nil {
+		return nil, "", "", fmt.Errorf("document has no file")
+	}
+
+	body, contentType, err := s.storage.Download(ctx, documentBucket, *doc.FilePath)
+	if err != nil {
+		return nil, "", "", fmt.Errorf("downloading file: %w", err)
+	}
+
+	// Use stored mime_type if available, fall back to storage response
+	if doc.MimeType != nil && *doc.MimeType != "" {
+		contentType = *doc.MimeType
+	}
+
+	return body, contentType, doc.Title, nil
+}
+
+func (s *DocumentService) Delete(ctx context.Context, tenantID, docID, userID uuid.UUID) error {
+	doc, err := s.GetByID(ctx, tenantID, docID)
+	if err != nil {
+		return err
+	}
+	if doc == nil {
+		return sql.ErrNoRows
+	}
+
+	// Delete from storage
+	if doc.FilePath != nil {
+		if err := s.storage.Delete(ctx, documentBucket, []string{*doc.FilePath}); err != nil {
+			return fmt.Errorf("deleting file from storage: %w", err)
+		}
+	}
+
+	// Delete database record
+	_, err = s.db.ExecContext(ctx,
+		"DELETE FROM documents WHERE id = $1 AND tenant_id = $2", docID, tenantID)
+	if err != nil {
+		return fmt.Errorf("deleting document record: %w", err)
+	}
+
+	// Log case event
+	createEvent(ctx, s.db, tenantID, doc.CaseID, userID, "document_deleted",
+		fmt.Sprintf("Document deleted: %s", doc.Title), nil)
+
+	return nil
+}
+
+func nilIfEmpty(s string) *string {
+	if s == "" {
+		return nil
+	}
+	return &s
+}

backend/internal/services/holidays.go

@@ -0,0 +1,193 @@
+package services
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/jmoiron/sqlx"
+)
+
+// Holiday represents a non-working day
+type Holiday struct {
+	Date       time.Time
+	Name       string
+	IsVacation bool // Part of court vacation period
+	IsClosure  bool // Single-day closure (public holiday)
+}
+
+// HolidayService manages holiday data and non-working day checks
+type HolidayService struct {
+	db *sqlx.DB
+	// Cached holidays by year
+	cache map[int][]Holiday
+}
+
+// NewHolidayService creates a holiday service
+func NewHolidayService(db *sqlx.DB) *HolidayService {
+	return &HolidayService{
+		db:    db,
+		cache: make(map[int][]Holiday),
+	}
+}
+
+// dbHoliday matches the holidays table schema
+type dbHoliday struct {
+	ID          int       `db:"id"`
+	Date        time.Time `db:"date"`
+	Name        string    `db:"name"`
+	Country     string    `db:"country"`
+	State       *string   `db:"state"`
+	HolidayType string    `db:"holiday_type"`
+}
+
+// LoadHolidaysForYear loads holidays from DB for a given year, merges with
+// German federal holidays, and caches the result.
+func (s *HolidayService) LoadHolidaysForYear(year int) ([]Holiday, error) {
+	if cached, ok := s.cache[year]; ok {
+		return cached, nil
+	}
+
+	holidays := make([]Holiday, 0, 30)
+
+	// Load from DB if available
+	if s.db != nil {
+		var dbHolidays []dbHoliday
+		err := s.db.Select(&dbHolidays,
+			`SELECT id, date, name, country, state, holiday_type
+			 FROM holidays
+			 WHERE EXTRACT(YEAR FROM date) = $1
+			 ORDER BY date`, year)
+		if err == nil {
+			for _, h := range dbHolidays {
+				holidays = append(holidays, Holiday{
+					Date:      h.Date,
+					Name:      h.Name,
+					IsClosure: h.HolidayType == "public_holiday" || h.HolidayType == "closure",
+					IsVacation: h.HolidayType == "vacation",
+				})
+			}
+		}
+		// If DB query fails, fall through to hardcoded holidays
+	}
+
+	// Always add German federal holidays (if not already present from DB)
+	federal := germanFederalHolidays(year)
+	existing := make(map[string]bool, len(holidays))
+	for _, h := range holidays {
+		existing[h.Date.Format("2006-01-02")] = true
+	}
+	for _, h := range federal {
+		key := h.Date.Format("2006-01-02")
+		if !existing[key] {
+			holidays = append(holidays, h)
+		}
+	}
+
+	s.cache[year] = holidays
+	return holidays, nil
+}
+
+// IsHoliday checks if a date is a holiday
+func (s *HolidayService) IsHoliday(date time.Time) *Holiday {
+	year := date.Year()
+	holidays, err := s.LoadHolidaysForYear(year)
+	if err != nil {
+		return nil
+	}
+
+	dateStr := date.Format("2006-01-02")
+	for i := range holidays {
+		if holidays[i].Date.Format("2006-01-02") == dateStr {
+			return &holidays[i]
+		}
+	}
+	return nil
+}
+
+// IsNonWorkingDay returns true if the date is a weekend or holiday
+func (s *HolidayService) IsNonWorkingDay(date time.Time) bool {
+	wd := date.Weekday()
+	if wd == time.Saturday || wd == time.Sunday {
+		return true
+	}
+	return s.IsHoliday(date) != nil
+}
+
+// AdjustForNonWorkingDays moves the date to the next working day
+// if it falls on a weekend or holiday.
+// Returns adjusted date, original date, and whether adjustment was made.
+func (s *HolidayService) AdjustForNonWorkingDays(date time.Time) (adjusted time.Time, original time.Time, wasAdjusted bool) {
+	original = date
+	adjusted = date
+
+	// Safety limit: max 30 days forward
+	for i := 0; i < 30 && s.IsNonWorkingDay(adjusted); i++ {
+		adjusted = adjusted.AddDate(0, 0, 1)
+		wasAdjusted = true
+	}
+
+	return adjusted, original, wasAdjusted
+}
+
+// ClearCache clears the holiday cache (useful after DB updates)
+func (s *HolidayService) ClearCache() {
+	s.cache = make(map[int][]Holiday)
+}
+
+// germanFederalHolidays returns all German federal public holidays for a year.
+// These are holidays observed in all 16 German states.
+func germanFederalHolidays(year int) []Holiday {
+	easterMonth, easterDay := CalculateEasterSunday(year)
+	easter := time.Date(year, time.Month(easterMonth), easterDay, 0, 0, 0, 0, time.UTC)
+
+	holidays := []Holiday{
+		{Date: time.Date(year, time.January, 1, 0, 0, 0, 0, time.UTC), Name: "Neujahr", IsClosure: true},
+		{Date: easter.AddDate(0, 0, -2), Name: "Karfreitag", IsClosure: true},
+		{Date: easter, Name: "Ostersonntag", IsClosure: true},
+		{Date: easter.AddDate(0, 0, 1), Name: "Ostermontag", IsClosure: true},
+		{Date: time.Date(year, time.May, 1, 0, 0, 0, 0, time.UTC), Name: "Tag der Arbeit", IsClosure: true},
+		{Date: easter.AddDate(0, 0, 39), Name: "Christi Himmelfahrt", IsClosure: true},
+		{Date: easter.AddDate(0, 0, 49), Name: "Pfingstsonntag", IsClosure: true},
+		{Date: easter.AddDate(0, 0, 50), Name: "Pfingstmontag", IsClosure: true},
+		{Date: time.Date(year, time.October, 3, 0, 0, 0, 0, time.UTC), Name: "Tag der Deutschen Einheit", IsClosure: true},
+		{Date: time.Date(year, time.December, 25, 0, 0, 0, 0, time.UTC), Name: "1. Weihnachtstag", IsClosure: true},
+		{Date: time.Date(year, time.December, 26, 0, 0, 0, 0, time.UTC), Name: "2. Weihnachtstag", IsClosure: true},
+	}
+
+	return holidays
+}
+
+// CalculateEasterSunday computes Easter Sunday using the Anonymous Gregorian algorithm.
+// Returns month (1-12) and day.
+func CalculateEasterSunday(year int) (int, int) {
+	a := year % 19
+	b := year / 100
+	c := year % 100
+	d := b / 4
+	e := b % 4
+	f := (b + 8) / 25
+	g := (b - f + 1) / 3
+	h := (19*a + b - d - g + 15) % 30
+	i := c / 4
+	k := c % 4
+	l := (32 + 2*e + 2*i - h - k) % 7
+	m := (a + 11*h + 22*l) / 451
+	month := (h + l - 7*m + 114) / 31
+	day := ((h + l - 7*m + 114) % 31) + 1
+	return month, day
+}
+
+// GetHolidaysForYear returns all holidays for a year (for API exposure)
+func (s *HolidayService) GetHolidaysForYear(year int) ([]Holiday, error) {
+	return s.LoadHolidaysForYear(year)
+}
+
+// FormatHolidayList returns a simple string representation of holidays for debugging
+func FormatHolidayList(holidays []Holiday) string {
+	var b strings.Builder
+	for _, h := range holidays {
+		fmt.Fprintf(&b, "%s: %s\n", h.Date.Format("2006-01-02"), h.Name)
+	}
+	return b.String()
+}

backend/internal/services/holidays_test.go

@@ -0,0 +1,121 @@
+package services
+
+import (
+	"testing"
+	"time"
+)
+
+func TestCalculateEasterSunday(t *testing.T) {
+	tests := []struct {
+		year      int
+		wantMonth int
+		wantDay   int
+	}{
+		{2024, 3, 31},
+		{2025, 4, 20},
+		{2026, 4, 5},
+		{2027, 3, 28},
+	}
+
+	for _, tt := range tests {
+		m, d := CalculateEasterSunday(tt.year)
+		if m != tt.wantMonth || d != tt.wantDay {
+			t.Errorf("CalculateEasterSunday(%d) = %d-%02d, want %d-%02d",
+				tt.year, m, d, tt.wantMonth, tt.wantDay)
+		}
+	}
+}
+
+func TestGermanFederalHolidays(t *testing.T) {
+	holidays := germanFederalHolidays(2026)
+
+	// Should have 11 federal holidays
+	if len(holidays) != 11 {
+		t.Fatalf("expected 11 federal holidays, got %d", len(holidays))
+	}
+
+	// Check Neujahr
+	if holidays[0].Name != "Neujahr" {
+		t.Errorf("first holiday should be Neujahr, got %s", holidays[0].Name)
+	}
+	if holidays[0].Date != time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC) {
+		t.Errorf("Neujahr should be Jan 1, got %s", holidays[0].Date)
+	}
+
+	// Check Karfreitag 2026 (Easter = Apr 5, so Good Friday = Apr 3)
+	found := false
+	for _, h := range holidays {
+		if h.Name == "Karfreitag" {
+			found = true
+			expected := time.Date(2026, 4, 3, 0, 0, 0, 0, time.UTC)
+			if h.Date != expected {
+				t.Errorf("Karfreitag 2026 should be %s, got %s", expected, h.Date)
+			}
+		}
+	}
+	if !found {
+		t.Error("Karfreitag not found in holidays")
+	}
+}
+
+func TestHolidayServiceIsNonWorkingDay(t *testing.T) {
+	svc := NewHolidayService(nil) // no DB, uses hardcoded holidays
+
+	// Saturday
+	sat := time.Date(2026, 3, 28, 0, 0, 0, 0, time.UTC)
+	if !svc.IsNonWorkingDay(sat) {
+		t.Error("Saturday should be non-working day")
+	}
+
+	// Sunday
+	sun := time.Date(2026, 3, 29, 0, 0, 0, 0, time.UTC)
+	if !svc.IsNonWorkingDay(sun) {
+		t.Error("Sunday should be non-working day")
+	}
+
+	// Regular Monday
+	mon := time.Date(2026, 3, 23, 0, 0, 0, 0, time.UTC)
+	if svc.IsNonWorkingDay(mon) {
+		t.Error("regular Monday should be a working day")
+	}
+
+	// Christmas (Friday Dec 25, 2026)
+	xmas := time.Date(2026, 12, 25, 0, 0, 0, 0, time.UTC)
+	if !svc.IsNonWorkingDay(xmas) {
+		t.Error("Christmas should be non-working day")
+	}
+
+	// New Year
+	newyear := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
+	if !svc.IsNonWorkingDay(newyear) {
+		t.Error("New Year should be non-working day")
+	}
+}
+
+func TestAdjustForNonWorkingDays(t *testing.T) {
+	svc := NewHolidayService(nil)
+
+	// Saturday -> Monday
+	sat := time.Date(2026, 3, 28, 0, 0, 0, 0, time.UTC)
+	adj, orig, adjusted := svc.AdjustForNonWorkingDays(sat)
+	if !adjusted {
+		t.Error("Saturday should be adjusted")
+	}
+	if orig != sat {
+		t.Error("original should be unchanged")
+	}
+	expected := time.Date(2026, 3, 30, 0, 0, 0, 0, time.UTC)
+	if adj != expected {
+		t.Errorf("Saturday should adjust to Monday %s, got %s", expected, adj)
+	}
+
+	// Regular Wednesday -> no adjustment
+	wed := time.Date(2026, 3, 25, 0, 0, 0, 0, time.UTC)
+	adj, _, adjusted = svc.AdjustForNonWorkingDays(wed)
+	if adjusted {
+		t.Error("Wednesday should not be adjusted")
+	}
+	if adj != wed {
+		t.Error("non-adjusted date should be unchanged")
+	}
+}

backend/internal/services/party_service.go

@@ -0,0 +1,152 @@
+package services
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"fmt"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+)
+
+type PartyService struct {
+	db *sqlx.DB
+}
+
+func NewPartyService(db *sqlx.DB) *PartyService {
+	return &PartyService{db: db}
+}
+
+type CreatePartyInput struct {
+	Name           string          `json:"name"`
+	Role           *string         `json:"role,omitempty"`
+	Representative *string         `json:"representative,omitempty"`
+	ContactInfo    json.RawMessage `json:"contact_info,omitempty"`
+}
+
+type UpdatePartyInput struct {
+	Name           *string         `json:"name,omitempty"`
+	Role           *string         `json:"role,omitempty"`
+	Representative *string         `json:"representative,omitempty"`
+	ContactInfo    json.RawMessage `json:"contact_info,omitempty"`
+}
+
+func (s *PartyService) ListByCase(ctx context.Context, tenantID, caseID uuid.UUID) ([]models.Party, error) {
+	var parties []models.Party
+	err := s.db.SelectContext(ctx, &parties,
+		"SELECT * FROM parties WHERE case_id = $1 AND tenant_id = $2 ORDER BY name",
+		caseID, tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("listing parties: %w", err)
+	}
+	return parties, nil
+}
+
+func (s *PartyService) Create(ctx context.Context, tenantID, caseID uuid.UUID, userID uuid.UUID, input CreatePartyInput) (*models.Party, error) {
+	// Verify case exists and belongs to tenant
+	var exists bool
+	err := s.db.GetContext(ctx, &exists,
+		"SELECT EXISTS(SELECT 1 FROM cases WHERE id = $1 AND tenant_id = $2)", caseID, tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("checking case: %w", err)
+	}
+	if !exists {
+		return nil, sql.ErrNoRows
+	}
+
+	id := uuid.New()
+	contactInfo := input.ContactInfo
+	if contactInfo == nil {
+		contactInfo = json.RawMessage("{}")
+	}
+
+	_, err = s.db.ExecContext(ctx,
+		`INSERT INTO parties (id, tenant_id, case_id, name, role, representative, contact_info)
+		 VALUES ($1, $2, $3, $4, $5, $6, $7)`,
+		id, tenantID, caseID, input.Name, input.Role, input.Representative, contactInfo)
+	if err != nil {
+		return nil, fmt.Errorf("creating party: %w", err)
+	}
+
+	// Log event
+	desc := fmt.Sprintf("Party added: %s", input.Name)
+	createEvent(ctx, s.db, tenantID, caseID, userID, "party_added", desc, nil)
+
+	var party models.Party
+	if err := s.db.GetContext(ctx, &party, "SELECT * FROM parties WHERE id = $1", id); err != nil {
+		return nil, fmt.Errorf("fetching created party: %w", err)
+	}
+	return &party, nil
+}
+
+func (s *PartyService) Update(ctx context.Context, tenantID, partyID uuid.UUID, input UpdatePartyInput) (*models.Party, error) {
+	// Verify party exists and belongs to tenant
+	var current models.Party
+	err := s.db.GetContext(ctx, &current,
+		"SELECT * FROM parties WHERE id = $1 AND tenant_id = $2", partyID, tenantID)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("fetching party: %w", err)
+	}
+
+	sets := []string{}
+	args := []interface{}{}
+	argIdx := 1
+
+	if input.Name != nil {
+		sets = append(sets, fmt.Sprintf("name = $%d", argIdx))
+		args = append(args, *input.Name)
+		argIdx++
+	}
+	if input.Role != nil {
+		sets = append(sets, fmt.Sprintf("role = $%d", argIdx))
+		args = append(args, *input.Role)
+		argIdx++
+	}
+	if input.Representative != nil {
+		sets = append(sets, fmt.Sprintf("representative = $%d", argIdx))
+		args = append(args, *input.Representative)
+		argIdx++
+	}
+	if input.ContactInfo != nil {
+		sets = append(sets, fmt.Sprintf("contact_info = $%d", argIdx))
+		args = append(args, input.ContactInfo)
+		argIdx++
+	}
+
+	if len(sets) == 0 {
+		return &current, nil
+	}
+
+	query := fmt.Sprintf("UPDATE parties SET %s WHERE id = $%d AND tenant_id = $%d",
+		joinStrings(sets, ", "), argIdx, argIdx+1)
+	args = append(args, partyID, tenantID)
+
+	if _, err := s.db.ExecContext(ctx, query, args...); err != nil {
+		return nil, fmt.Errorf("updating party: %w", err)
+	}
+
+	var updated models.Party
+	if err := s.db.GetContext(ctx, &updated, "SELECT * FROM parties WHERE id = $1", partyID); err != nil {
+		return nil, fmt.Errorf("fetching updated party: %w", err)
+	}
+	return &updated, nil
+}
+
+func (s *PartyService) Delete(ctx context.Context, tenantID, partyID uuid.UUID) error {
+	result, err := s.db.ExecContext(ctx,
+		"DELETE FROM parties WHERE id = $1 AND tenant_id = $2", partyID, tenantID)
+	if err != nil {
+		return fmt.Errorf("deleting party: %w", err)
+	}
+	rows, _ := result.RowsAffected()
+	if rows == 0 {
+		return sql.ErrNoRows
+	}
+	return nil
+}

backend/internal/services/storage.go

@@ -0,0 +1,112 @@
+package services
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+// StorageClient interacts with Supabase Storage via REST API.
+type StorageClient struct {
+	baseURL    string
+	serviceKey string
+	httpClient *http.Client
+}
+
+func NewStorageClient(supabaseURL, serviceKey string) *StorageClient {
+	return &StorageClient{
+		baseURL:    supabaseURL,
+		serviceKey: serviceKey,
+		httpClient: &http.Client{},
+	}
+}
+
+// Upload stores a file in the given bucket at the specified path.
+func (s *StorageClient) Upload(ctx context.Context, bucket, path, contentType string, data io.Reader) error {
+	url := fmt.Sprintf("%s/storage/v1/object/%s/%s", s.baseURL, bucket, path)
+
+	req, err := http.NewRequestWithContext(ctx, "POST", url, data)
+	if err != nil {
+		return fmt.Errorf("creating upload request: %w", err)
+	}
+
+	req.Header.Set("Authorization", "Bearer "+s.serviceKey)
+	req.Header.Set("Content-Type", contentType)
+	req.Header.Set("x-upsert", "true")
+
+	resp, err := s.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("uploading to storage: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
+		body, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("storage upload failed (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	return nil
+}
+
+// Download retrieves a file from storage. Caller must close the returned ReadCloser.
+func (s *StorageClient) Download(ctx context.Context, bucket, path string) (io.ReadCloser, string, error) {
+	url := fmt.Sprintf("%s/storage/v1/object/%s/%s", s.baseURL, bucket, path)
+
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return nil, "", fmt.Errorf("creating download request: %w", err)
+	}
+
+	req.Header.Set("Authorization", "Bearer "+s.serviceKey)
+
+	resp, err := s.httpClient.Do(req)
+	if err != nil {
+		return nil, "", fmt.Errorf("downloading from storage: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		resp.Body.Close()
+		if resp.StatusCode == http.StatusNotFound {
+			return nil, "", fmt.Errorf("file not found in storage")
+		}
+		body, _ := io.ReadAll(resp.Body)
+		return nil, "", fmt.Errorf("storage download failed (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	ct := resp.Header.Get("Content-Type")
+	return resp.Body, ct, nil
+}
+
+// Delete removes files from storage by their paths.
+func (s *StorageClient) Delete(ctx context.Context, bucket string, paths []string) error {
+	url := fmt.Sprintf("%s/storage/v1/object/%s", s.baseURL, bucket)
+
+	body, err := json.Marshal(map[string][]string{"prefixes": paths})
+	if err != nil {
+		return fmt.Errorf("marshaling delete request: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "DELETE", url, bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("creating delete request: %w", err)
+	}
+
+	req.Header.Set("Authorization", "Bearer "+s.serviceKey)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := s.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("deleting from storage: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNoContent {
+		respBody, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("storage delete failed (status %d): %s", resp.StatusCode, string(respBody))
+	}
+
+	return nil
+}

backend/internal/services/tenant_service.go

@@ -0,0 +1,211 @@
+package services
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+
+	"github.com/google/uuid"
+	"github.com/jmoiron/sqlx"
+
+	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
+)
+
+type TenantService struct {
+	db *sqlx.DB
+}
+
+func NewTenantService(db *sqlx.DB) *TenantService {
+	return &TenantService{db: db}
+}
+
+// Create creates a new tenant and assigns the creator as owner.
+func (s *TenantService) Create(ctx context.Context, userID uuid.UUID, name, slug string) (*models.Tenant, error) {
+	tx, err := s.db.BeginTxx(ctx, nil)
+	if err != nil {
+		return nil, fmt.Errorf("begin transaction: %w", err)
+	}
+	defer tx.Rollback()
+
+	var tenant models.Tenant
+	err = tx.QueryRowxContext(ctx,
+		`INSERT INTO tenants (name, slug) VALUES ($1, $2) RETURNING id, name, slug, settings, created_at, updated_at`,
+		name, slug,
+	).StructScan(&tenant)
+	if err != nil {
+		return nil, fmt.Errorf("insert tenant: %w", err)
+	}
+
+	_, err = tx.ExecContext(ctx,
+		`INSERT INTO user_tenants (user_id, tenant_id, role) VALUES ($1, $2, 'owner')`,
+		userID, tenant.ID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("assign owner: %w", err)
+	}
+
+	if err := tx.Commit(); err != nil {
+		return nil, fmt.Errorf("commit: %w", err)
+	}
+
+	return &tenant, nil
+}
+
+// ListForUser returns all tenants the user belongs to.
+func (s *TenantService) ListForUser(ctx context.Context, userID uuid.UUID) ([]models.TenantWithRole, error) {
+	var tenants []models.TenantWithRole
+	err := s.db.SelectContext(ctx, &tenants,
+		`SELECT t.id, t.name, t.slug, t.settings, t.created_at, t.updated_at, ut.role
+		 FROM tenants t
+		 JOIN user_tenants ut ON ut.tenant_id = t.id
+		 WHERE ut.user_id = $1
+		 ORDER BY t.name`,
+		userID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("list tenants: %w", err)
+	}
+	return tenants, nil
+}
+
+// GetByID returns a single tenant. The caller must verify the user has access.
+func (s *TenantService) GetByID(ctx context.Context, tenantID uuid.UUID) (*models.Tenant, error) {
+	var tenant models.Tenant
+	err := s.db.GetContext(ctx, &tenant,
+		`SELECT id, name, slug, settings, created_at, updated_at FROM tenants WHERE id = $1`,
+		tenantID,
+	)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("get tenant: %w", err)
+	}
+	return &tenant, nil
+}
+
+// GetUserRole returns the user's role in a tenant, or empty string if not a member.
+func (s *TenantService) GetUserRole(ctx context.Context, userID, tenantID uuid.UUID) (string, error) {
+	var role string
+	err := s.db.GetContext(ctx, &role,
+		`SELECT role FROM user_tenants WHERE user_id = $1 AND tenant_id = $2`,
+		userID, tenantID,
+	)
+	if err == sql.ErrNoRows {
+		return "", nil
+	}
+	if err != nil {
+		return "", fmt.Errorf("get user role: %w", err)
+	}
+	return role, nil
+}
+
+// FirstTenantForUser returns the user's first tenant (by name), used as default.
+func (s *TenantService) FirstTenantForUser(ctx context.Context, userID uuid.UUID) (*uuid.UUID, error) {
+	var tenantID uuid.UUID
+	err := s.db.GetContext(ctx, &tenantID,
+		`SELECT t.id FROM tenants t
+		 JOIN user_tenants ut ON ut.tenant_id = t.id
+		 WHERE ut.user_id = $1
+		 ORDER BY t.name LIMIT 1`,
+		userID,
+	)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("first tenant: %w", err)
+	}
+	return &tenantID, nil
+}
+
+// ListMembers returns all members of a tenant.
+func (s *TenantService) ListMembers(ctx context.Context, tenantID uuid.UUID) ([]models.UserTenant, error) {
+	var members []models.UserTenant
+	err := s.db.SelectContext(ctx, &members,
+		`SELECT user_id, tenant_id, role, created_at FROM user_tenants WHERE tenant_id = $1 ORDER BY created_at`,
+		tenantID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("list members: %w", err)
+	}
+	return members, nil
+}
+
+// InviteByEmail looks up a user by email in auth.users and adds them to the tenant.
+func (s *TenantService) InviteByEmail(ctx context.Context, tenantID uuid.UUID, email, role string) (*models.UserTenant, error) {
+	// Look up user in Supabase auth.users
+	var userID uuid.UUID
+	err := s.db.GetContext(ctx, &userID,
+		`SELECT id FROM auth.users WHERE email = $1`,
+		email,
+	)
+	if err == sql.ErrNoRows {
+		return nil, fmt.Errorf("no user found with email %s", email)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("lookup user: %w", err)
+	}
+
+	// Check if already a member
+	var exists bool
+	err = s.db.GetContext(ctx, &exists,
+		`SELECT EXISTS(SELECT 1 FROM user_tenants WHERE user_id = $1 AND tenant_id = $2)`,
+		userID, tenantID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("check membership: %w", err)
+	}
+	if exists {
+		return nil, fmt.Errorf("user is already a member of this tenant")
+	}
+
+	var ut models.UserTenant
+	err = s.db.QueryRowxContext(ctx,
+		`INSERT INTO user_tenants (user_id, tenant_id, role) VALUES ($1, $2, $3)
+		 RETURNING user_id, tenant_id, role, created_at`,
+		userID, tenantID, role,
+	).StructScan(&ut)
+	if err != nil {
+		return nil, fmt.Errorf("invite user: %w", err)
+	}
+
+	return &ut, nil
+}
+
+// RemoveMember removes a user from a tenant. Cannot remove the last owner.
+func (s *TenantService) RemoveMember(ctx context.Context, tenantID, userID uuid.UUID) error {
+	// Check if the user being removed is an owner
+	role, err := s.GetUserRole(ctx, userID, tenantID)
+	if err != nil {
+		return fmt.Errorf("check role: %w", err)
+	}
+	if role == "" {
+		return fmt.Errorf("user is not a member of this tenant")
+	}
+
+	if role == "owner" {
+		// Count owners — prevent removing the last one
+		var ownerCount int
+		err := s.db.GetContext(ctx, &ownerCount,
+			`SELECT COUNT(*) FROM user_tenants WHERE tenant_id = $1 AND role = 'owner'`,
+			tenantID,
+		)
+		if err != nil {
+			return fmt.Errorf("count owners: %w", err)
+		}
+		if ownerCount <= 1 {
+			return fmt.Errorf("cannot remove the last owner of a tenant")
+		}
+	}
+
+	_, err = s.db.ExecContext(ctx,
+		`DELETE FROM user_tenants WHERE user_id = $1 AND tenant_id = $2`,
+		userID, tenantID,
+	)
+	if err != nil {
+		return fmt.Errorf("remove member: %w", err)
+	}
+
+	return nil
+}

frontend/bun.lock

@@ -5,9 +5,15 @@
     "": {
       "name": "frontend",
       "dependencies": {
+        "@supabase/ssr": "^0.9.0",
+        "@supabase/supabase-js": "^2.100.0",
+        "@tanstack/react-query": "^5.95.2",
+        "date-fns": "^4.1.0",
+        "lucide-react": "^1.6.0",
         "next": "15.5.14",
         "react": "19.1.0",
         "react-dom": "19.1.0",
+        "sonner": "^2.0.7",
       },
       "devDependencies": {
         "@eslint/eslintrc": "^3",
@@ -151,6 +157,22 @@
 
     "@rushstack/eslint-patch": ["@rushstack/eslint-patch@1.16.1", "", {}, "sha512-TvZbIpeKqGQQ7X0zSCvPH9riMSFQFSggnfBjFZ1mEoILW+UuXCKwOoPcgjMwiUtRqFZ8jWhPJc4um14vC6I4ag=="],
 
+    "@supabase/auth-js": ["@supabase/auth-js@2.100.0", "", { "dependencies": { "tslib": "2.8.1" } }, "sha512-pdT3ye3UVRN1Cg0wom6BmyY+XTtp5DiJaYnPi6j8ht5i8Lq8kfqxJMJz9GI9YDKk3w1nhGOPnh6Qz5qpyYm+1w=="],
+
+    "@supabase/functions-js": ["@supabase/functions-js@2.100.0", "", { "dependencies": { "tslib": "2.8.1" } }, "sha512-keLg79RPwP+uiwHuxFPTFgDRxPV46LM4j/swjyR2GKJgWniTVSsgiBHfbIBDcrQwehLepy09b/9QSHUywtKRWQ=="],
+
+    "@supabase/phoenix": ["@supabase/phoenix@0.4.0", "", {}, "sha512-RHSx8bHS02xwfHdAbX5Lpbo6PXbgyf7lTaXTlwtFDPwOIw64NnVRwFAXGojHhjtVYI+PEPNSWwkL90f4agN3bw=="],
+
+    "@supabase/postgrest-js": ["@supabase/postgrest-js@2.100.0", "", { "dependencies": { "tslib": "2.8.1" } }, "sha512-xYNvNbBJaXOGcrZ44wxwp5830uo1okMHGS8h8dm3u4f0xcZ39yzbryUsubTJW41MG2gbL/6U57cA4Pi6YMZ9pA=="],
+
+    "@supabase/realtime-js": ["@supabase/realtime-js@2.100.0", "", { "dependencies": { "@supabase/phoenix": "^0.4.0", "@types/ws": "^8.18.1", "tslib": "2.8.1", "ws": "^8.18.2" } }, "sha512-2AZs00zzEF0HuCKY8grz5eCYlwEfVi5HONLZFoNR6aDfxQivl8zdQYNjyFoqN2MZiVhQHD7u6XV/xHwM8mCEHw=="],
+
+    "@supabase/ssr": ["@supabase/ssr@0.9.0", "", { "dependencies": { "cookie": "^1.0.2" }, "peerDependencies": { "@supabase/supabase-js": "^2.97.0" } }, "sha512-UFY6otYV3yqCgV+AyHj80vNkTvbf1Gas2LW4dpbQ4ap6p6v3eB2oaDfcI99jsuJzwVBCFU4BJI+oDYyhNk1z0Q=="],
+
+    "@supabase/storage-js": ["@supabase/storage-js@2.100.0", "", { "dependencies": { "iceberg-js": "^0.8.1", "tslib": "2.8.1" } }, "sha512-d4EeuK6RNIgYNA2MU9kj8lQrLm5AzZ+WwpWjGkii6SADQNIGTC/uiaTRu02XJ5AmFALQfo8fLl9xuCkO6Xw+iQ=="],
+
+    "@supabase/supabase-js": ["@supabase/supabase-js@2.100.0", "", { "dependencies": { "@supabase/auth-js": "2.100.0", "@supabase/functions-js": "2.100.0", "@supabase/postgrest-js": "2.100.0", "@supabase/realtime-js": "2.100.0", "@supabase/storage-js": "2.100.0" } }, "sha512-r0tlcukejJXJ1m/2eG/Ya5eYs4W8AC7oZfShpG3+SIo/eIU9uIt76ZeYI1SoUwUmcmzlAbgch+HDZDR/toVQPQ=="],
+
     "@swc/helpers": ["@swc/helpers@0.5.15", "", { "dependencies": { "tslib": "^2.8.0" } }, "sha512-JQ5TuMi45Owi4/BIMAJBoSQoOJu12oOk/gADqlcUL9JEdHB8vyjUSsxqeNXnmXHjYKMi2WcYtezGEEhqUI/E2g=="],
 
     "@tailwindcss/node": ["@tailwindcss/node@4.2.2", "", { "dependencies": { "@jridgewell/remapping": "^2.3.5", "enhanced-resolve": "^5.19.0", "jiti": "^2.6.1", "lightningcss": "1.32.0", "magic-string": "^0.30.21", "source-map-js": "^1.2.1", "tailwindcss": "4.2.2" } }, "sha512-pXS+wJ2gZpVXqFaUEjojq7jzMpTGf8rU6ipJz5ovJV6PUGmlJ+jvIwGrzdHdQ80Sg+wmQxUFuoW1UAAwHNEdFA=="],
@@ -183,6 +205,10 @@
 
     "@tailwindcss/postcss": ["@tailwindcss/postcss@4.2.2", "", { "dependencies": { "@alloc/quick-lru": "^5.2.0", "@tailwindcss/node": "4.2.2", "@tailwindcss/oxide": "4.2.2", "postcss": "^8.5.6", "tailwindcss": "4.2.2" } }, "sha512-n4goKQbW8RVXIbNKRB/45LzyUqN451deQK0nzIeauVEqjlI49slUlgKYJM2QyUzap/PcpnS7kzSUmPb1sCRvYQ=="],
 
+    "@tanstack/query-core": ["@tanstack/query-core@5.95.2", "", {}, "sha512-o4T8vZHZET4Bib3jZ/tCW9/7080urD4c+0/AUaYVpIqOsr7y0reBc1oX3ttNaSW5mYyvZHctiQ/UOP2PfdmFEQ=="],
+
+    "@tanstack/react-query": ["@tanstack/react-query@5.95.2", "", { "dependencies": { "@tanstack/query-core": "5.95.2" }, "peerDependencies": { "react": "^18 || ^19" } }, "sha512-/wGkvLj/st5Ud1Q76KF1uFxScV7WeqN1slQx5280ycwAyYkIPGaRZAEgHxe3bjirSd5Zpwkj6zNcR4cqYni/ZA=="],
+
     "@tybys/wasm-util": ["@tybys/wasm-util@0.10.1", "", { "dependencies": { "tslib": "^2.4.0" } }, "sha512-9tTaPJLSiejZKx+Bmog4uSubteqTvFrVrURwkmHixBo0G4seD0zUxp98E1DzUBJxLQ3NPwXrGKDiVjwx/DpPsg=="],
 
     "@types/estree": ["@types/estree@1.0.8", "", {}, "sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w=="],
@@ -197,6 +223,8 @@
 
     "@types/react-dom": ["@types/react-dom@19.2.3", "", { "peerDependencies": { "@types/react": "^19.2.0" } }, "sha512-jp2L/eY6fn+KgVVQAOqYItbF0VY/YApe5Mz2F0aykSO8gx31bYCZyvSeYxCHKvzHG5eZjc+zyaS5BrBWya2+kQ=="],
 
+    "@types/ws": ["@types/ws@8.18.1", "", { "dependencies": { "@types/node": "*" } }, "sha512-ThVF6DCVhA8kUGy+aazFQ4kXQ7E1Ty7A3ypFOe0IcJV8O/M511G99AW24irKrW56Wt44yG9+ij8FaqoBGkuBXg=="],
+
     "@typescript-eslint/eslint-plugin": ["@typescript-eslint/eslint-plugin@8.57.2", "", { "dependencies": { "@eslint-community/regexpp": "^4.12.2", "@typescript-eslint/scope-manager": "8.57.2", "@typescript-eslint/type-utils": "8.57.2", "@typescript-eslint/utils": "8.57.2", "@typescript-eslint/visitor-keys": "8.57.2", "ignore": "^7.0.5", "natural-compare": "^1.4.0", "ts-api-utils": "^2.4.0" }, "peerDependencies": { "@typescript-eslint/parser": "^8.57.2", "eslint": "^8.57.0 || ^9.0.0 || ^10.0.0", "typescript": ">=4.8.4 <6.0.0" } }, "sha512-NZZgp0Fm2IkD+La5PR81sd+g+8oS6JwJje+aRWsDocxHkjyRw0J5L5ZTlN3LI1LlOcGL7ph3eaIUmTXMIjLk0w=="],
 
     "@typescript-eslint/parser": ["@typescript-eslint/parser@8.57.2", "", { "dependencies": { "@typescript-eslint/scope-manager": "8.57.2", "@typescript-eslint/types": "8.57.2", "@typescript-eslint/typescript-estree": "8.57.2", "@typescript-eslint/visitor-keys": "8.57.2", "debug": "^4.4.3" }, "peerDependencies": { "eslint": "^8.57.0 || ^9.0.0 || ^10.0.0", "typescript": ">=4.8.4 <6.0.0" } }, "sha512-30ScMRHIAD33JJQkgfGW1t8CURZtjc2JpTrq5n2HFhOefbAhb7ucc7xJwdWcrEtqUIYJ73Nybpsggii6GtAHjA=="],
@@ -319,6 +347,8 @@
 
     "concat-map": ["concat-map@0.0.1", "", {}, "sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg=="],
 
+    "cookie": ["cookie@1.1.1", "", {}, "sha512-ei8Aos7ja0weRpFzJnEA9UHJ/7XQmqglbRwnf2ATjcB9Wq874VKH9kfjjirM6UhU2/E5fFYadylyhFldcqSidQ=="],
+
     "cross-spawn": ["cross-spawn@7.0.6", "", { "dependencies": { "path-key": "^3.1.0", "shebang-command": "^2.0.0", "which": "^2.0.1" } }, "sha512-uV2QOWP2nWzsy2aMp8aRibhi9dlzF5Hgh5SHaB9OiTGEyDTiJJyx0uy51QXdyWbtAHNua4XJzUKca3OzKUd3vA=="],
 
     "csstype": ["csstype@3.2.3", "", {}, "sha512-z1HGKcYy2xA8AGQfwrn0PAy+PB7X/GSj3UVJW9qKyn43xWa+gl5nXmU4qqLMRzWVLFC8KusUX8T/0kCiOYpAIQ=="],
@@ -331,6 +361,8 @@
 
     "data-view-byte-offset": ["data-view-byte-offset@1.0.1", "", { "dependencies": { "call-bound": "^1.0.2", "es-errors": "^1.3.0", "is-data-view": "^1.0.1" } }, "sha512-BS8PfmtDGnrgYdOonGZQdLZslWIeCGFP9tpan0hi1Co2Zr2NKADsvGYA8XxuG/4UWgJ6Cjtv+YJnB6MM69QGlQ=="],
 
+    "date-fns": ["date-fns@4.1.0", "", {}, "sha512-Ukq0owbQXxa/U3EGtsdVBkR1w7KOQ5gIBqdH2hkvknzZPYvBxb/aa6E8L7tmjFtkwZBu3UXBbjIgPo/Ez4xaNg=="],
+
     "debug": ["debug@4.4.3", "", { "dependencies": { "ms": "^2.1.3" } }, "sha512-RGwwWnwQvkVfavKVt22FGLw+xYSdzARwm0ru6DhTVA3umU5hZc28V3kO4stgYryrTlLpuvgI9GiijltAjNbcqA=="],
 
     "deep-is": ["deep-is@0.1.4", "", {}, "sha512-oIPzksmTg4/MriiaYGO+okXDT7ztn/w3Eptv/+gSIdMdKsJo0u4CfYNFJPy+4SKMuCqGw2wxnA+URMg3t8a/bQ=="],
@@ -463,6 +495,8 @@
 
     "hasown": ["hasown@2.0.2", "", { "dependencies": { "function-bind": "^1.1.2" } }, "sha512-0hJU9SCPvmMzIBdZFqNPXWa6dqh7WdH0cII9y+CyS8rG3nL48Bclra9HmKhVVUHyPWNH5Y7xDwAB7bfgSjkUMQ=="],
 
+    "iceberg-js": ["iceberg-js@0.8.1", "", {}, "sha512-1dhVQZXhcHje7798IVM+xoo/1ZdVfzOMIc8/rgVSijRK38EDqOJoGula9N/8ZI5RD8QTxNQtK/Gozpr+qUqRRA=="],
+
     "ignore": ["ignore@5.3.2", "", {}, "sha512-hsBTNUqQTDwkWtcdYI2i06Y/nUBEsNEDJKjWdigLvegy8kDuJAS8uRlpkkcQpyEXL0Z/pjDy5HBmMjRCJ2gq+g=="],
 
     "import-fresh": ["import-fresh@3.3.1", "", { "dependencies": { "parent-module": "^1.0.0", "resolve-from": "^4.0.0" } }, "sha512-TR3KfrTZTYLPB6jUjfx6MF9WcWrHL9su5TObK4ZkYgBdWKPOFoSoQIdEuTuR82pmtxH2spWG9h6etwfr1pLBqQ=="],
@@ -583,6 +617,8 @@
 
     "loose-envify": ["loose-envify@1.4.0", "", { "dependencies": { "js-tokens": "^3.0.0 || ^4.0.0" }, "bin": { "loose-envify": "cli.js" } }, "sha512-lyuxPGr/Wfhrlem2CL/UcnUc1zcqKAImBDzukY7Y5F/yQiNdko6+fRLevlw1HgMySw7f611UIY408EtxRSoK3Q=="],
 
+    "lucide-react": ["lucide-react@1.6.0", "", { "peerDependencies": { "react": "^16.5.1 || ^17.0.0 || ^18.0.0 || ^19.0.0" } }, "sha512-YxLKVCOF5ZDI1AhKQE5IBYMY9y/Nr4NT15+7QEWpsTSVCdn4vmZhww+6BP76jWYjQx8rSz1Z+gGme1f+UycWEw=="],
+
     "magic-string": ["magic-string@0.30.21", "", { "dependencies": { "@jridgewell/sourcemap-codec": "^1.5.5" } }, "sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ=="],
 
     "math-intrinsics": ["math-intrinsics@1.1.0", "", {}, "sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g=="],
@@ -705,6 +741,8 @@
 
     "side-channel-weakmap": ["side-channel-weakmap@1.0.2", "", { "dependencies": { "call-bound": "^1.0.2", "es-errors": "^1.3.0", "get-intrinsic": "^1.2.5", "object-inspect": "^1.13.3", "side-channel-map": "^1.0.1" } }, "sha512-WPS/HvHQTYnHisLo9McqBHOJk2FkHO/tlpvldyrnem4aeQp4hai3gythswg6p01oSoTl58rcpiFAjF2br2Ak2A=="],
 
+    "sonner": ["sonner@2.0.7", "", { "peerDependencies": { "react": "^18.0.0 || ^19.0.0 || ^19.0.0-rc", "react-dom": "^18.0.0 || ^19.0.0 || ^19.0.0-rc" } }, "sha512-W6ZN4p58k8aDKA4XPcx2hpIQXBRAgyiWVkYhT7CvK6D3iAu7xjvVyhQHg2/iaKJZ1XVJ4r7XuwGL+WGEK37i9w=="],
+
     "source-map-js": ["source-map-js@1.2.1", "", {}, "sha512-UXWMKhLOwVKb728IUtQPXxfYU+usdybtUrK/8uGE8CQMvrhOpwvzDBwj0QhSL7MQc7vIsISBG8VQ8+IDQxpfQA=="],
 
     "stable-hash": ["stable-hash@0.0.5", "", {}, "sha512-+L3ccpzibovGXFK+Ap/f8LOS0ahMrHTf3xu7mMLSpEGU0EO9ucaysSylKo9eRDFNhWve/y275iPmIZ4z39a9iA=="],
@@ -779,6 +817,8 @@
 
     "word-wrap": ["word-wrap@1.2.5", "", {}, "sha512-BN22B5eaMMI9UMtjrGd5g5eCYPpCPDUy0FJXbYsaT5zYxjFOckS53SQDE3pWkVoWpHXVb3BrYcEN4Twa55B5cA=="],
 
+    "ws": ["ws@8.20.0", "", { "peerDependencies": { "bufferutil": "^4.0.1", "utf-8-validate": ">=5.0.2" }, "optionalPeers": ["bufferutil", "utf-8-validate"] }, "sha512-sAt8BhgNbzCtgGbt2OxmpuryO63ZoDk/sqaB/znQm94T4fCEsy/yV+7CdC1kJhOU9lboAEU7R3kquuycDoibVA=="],
+
     "yocto-queue": ["yocto-queue@0.1.0", "", {}, "sha512-rVksvsnNCdJ/ohGc6xgPwyN8eheCxsiLM8mxuE/t/mOVqJewPuO1miLpTHQiRgTKCLexL4MeAFVagts7HmNZ2Q=="],
 
     "@eslint-community/eslint-utils/eslint-visitor-keys": ["eslint-visitor-keys@3.4.3", "", {}, "sha512-wpc+LXeiyiisxPlEkUzU6svyS1frIO3Mgxj1fdy7Pm8Ygzguax2N3Fa/D/ag1WqbOprdI+uY6wMUl8/a2G+iag=="],

frontend/next-env.d.ts

@@ -0,0 +1,6 @@
+/// <reference types="next" />
+/// <reference types="next/image-types/global" />
+/// <reference path="./.next/types/routes.d.ts" />
+
+// NOTE: This file should not be edited
+// see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

frontend/package.json

@@ -9,9 +9,15 @@
     "lint": "eslint"
   },
   "dependencies": {
+    "@supabase/ssr": "^0.9.0",
+    "@supabase/supabase-js": "^2.100.0",
+    "@tanstack/react-query": "^5.95.2",
+    "date-fns": "^4.1.0",
+    "lucide-react": "^1.6.0",
+    "next": "15.5.14",
     "react": "19.1.0",
     "react-dom": "19.1.0",
-    "next": "15.5.14"
+    "sonner": "^2.0.7"
   },
   "devDependencies": {
     "typescript": "^5",

frontend/src/app/(app)/cases/[id]/page.tsx

@@ -0,0 +1,267 @@
+"use client";
+
+import { useQuery } from "@tanstack/react-query";
+import { useParams } from "next/navigation";
+import { api } from "@/lib/api";
+import type { Case, CaseEvent, Party, Deadline, Document } from "@/lib/types";
+import { CaseTimeline } from "@/components/cases/CaseTimeline";
+import { PartyList } from "@/components/cases/PartyList";
+import { ArrowLeft, Clock, FileText, Users, Activity } from "lucide-react";
+import { format } from "date-fns";
+import { de } from "date-fns/locale";
+import Link from "next/link";
+import { useState } from "react";
+
+interface CaseDetail extends Case {
+  parties: Party[];
+  recent_events: CaseEvent[];
+  deadlines_count: number;
+}
+
+const STATUS_BADGE: Record<string, string> = {
+  active: "bg-emerald-50 text-emerald-700",
+  pending: "bg-amber-50 text-amber-700",
+  closed: "bg-neutral-100 text-neutral-600",
+  archived: "bg-neutral-100 text-neutral-400",
+};
+
+const TABS = [
+  { key: "timeline", label: "Verlauf", icon: Activity },
+  { key: "deadlines", label: "Fristen", icon: Clock },
+  { key: "documents", label: "Dokumente", icon: FileText },
+  { key: "parties", label: "Parteien", icon: Users },
+] as const;
+
+type TabKey = (typeof TABS)[number]["key"];
+
+export default function CaseDetailPage() {
+  const { id } = useParams<{ id: string }>();
+  const [activeTab, setActiveTab] = useState<TabKey>("timeline");
+
+  const { data: caseDetail, isLoading } = useQuery({
+    queryKey: ["case", id],
+    queryFn: () => api.get<CaseDetail>(`/cases/${id}`),
+  });
+
+  const { data: deadlinesData } = useQuery({
+    queryKey: ["case-deadlines", id],
+    queryFn: () =>
+      api.get<{ deadlines: Deadline[]; total: number }>(
+        `/deadlines?case_id=${id}`,
+      ),
+    enabled: activeTab === "deadlines",
+  });
+
+  const { data: documentsData } = useQuery({
+    queryKey: ["case-documents", id],
+    queryFn: () => api.get<Document[]>(`/cases/${id}/documents`),
+    enabled: activeTab === "documents",
+  });
+
+  if (isLoading) {
+    return (
+      <div className="py-12 text-center text-sm text-neutral-400">
+        Laden...
+      </div>
+    );
+  }
+
+  if (!caseDetail) {
+    return (
+      <div className="py-12 text-center text-sm text-neutral-400">
+        Akte nicht gefunden.
+      </div>
+    );
+  }
+
+  const deadlines = deadlinesData?.deadlines ?? [];
+  const documents = documentsData ?? [];
+
+  return (
+    <div>
+      <Link
+        href="/cases"
+        className="mb-4 inline-flex items-center gap-1 text-sm text-neutral-500 hover:text-neutral-700"
+      >
+        <ArrowLeft className="h-3.5 w-3.5" />
+        Zuruck zu Akten
+      </Link>
+
+      <div className="flex items-start justify-between">
+        <div>
+          <div className="flex items-center gap-3">
+            <h1 className="text-lg font-semibold text-neutral-900">
+              {caseDetail.title}
+            </h1>
+            <span
+              className={`inline-block rounded-full px-2 py-0.5 text-xs font-medium ${STATUS_BADGE[caseDetail.status] ?? "bg-neutral-100 text-neutral-500"}`}
+            >
+              {caseDetail.status}
+            </span>
+          </div>
+          <div className="mt-1 flex gap-4 text-sm text-neutral-500">
+            <span>Az. {caseDetail.case_number}</span>
+            {caseDetail.case_type && <span>{caseDetail.case_type}</span>}
+            {caseDetail.court && <span>{caseDetail.court}</span>}
+            {caseDetail.court_ref && <span>({caseDetail.court_ref})</span>}
+          </div>
+        </div>
+        <div className="text-right text-xs text-neutral-400">
+          <p>
+            Erstellt:{" "}
+            {format(new Date(caseDetail.created_at), "d. MMM yyyy", {
+              locale: de,
+            })}
+          </p>
+          <p>
+            Aktualisiert:{" "}
+            {format(new Date(caseDetail.updated_at), "d. MMM yyyy", {
+              locale: de,
+            })}
+          </p>
+        </div>
+      </div>
+
+      {caseDetail.ai_summary && (
+        <div className="mt-4 rounded-md border border-blue-100 bg-blue-50 px-4 py-3 text-sm text-blue-800">
+          {caseDetail.ai_summary}
+        </div>
+      )}
+
+      <div className="mt-6 border-b border-neutral-200">
+        <nav className="-mb-px flex gap-4">
+          {TABS.map((tab) => (
+            <button
+              key={tab.key}
+              onClick={() => setActiveTab(tab.key)}
+              className={`inline-flex items-center gap-1.5 border-b-2 px-1 pb-2.5 text-sm font-medium transition-colors ${
+                activeTab === tab.key
+                  ? "border-neutral-900 text-neutral-900"
+                  : "border-transparent text-neutral-400 hover:text-neutral-600"
+              }`}
+            >
+              <tab.icon className="h-4 w-4" />
+              {tab.label}
+              {tab.key === "deadlines" && caseDetail.deadlines_count > 0 && (
+                <span className="ml-1 rounded-full bg-neutral-100 px-1.5 py-0.5 text-xs text-neutral-500">
+                  {caseDetail.deadlines_count}
+                </span>
+              )}
+              {tab.key === "parties" && caseDetail.parties.length > 0 && (
+                <span className="ml-1 rounded-full bg-neutral-100 px-1.5 py-0.5 text-xs text-neutral-500">
+                  {caseDetail.parties.length}
+                </span>
+              )}
+            </button>
+          ))}
+        </nav>
+      </div>
+
+      <div className="mt-6">
+        {activeTab === "timeline" && (
+          <CaseTimeline events={caseDetail.recent_events ?? []} />
+        )}
+
+        {activeTab === "deadlines" && (
+          <DeadlinesList deadlines={deadlines} />
+        )}
+
+        {activeTab === "documents" && (
+          <DocumentsList documents={documents} />
+        )}
+
+        {activeTab === "parties" && (
+          <PartyList caseId={id} parties={caseDetail.parties ?? []} />
+        )}
+      </div>
+    </div>
+  );
+}
+
+function DeadlinesList({ deadlines }: { deadlines: Deadline[] }) {
+  if (deadlines.length === 0) {
+    return (
+      <p className="py-8 text-center text-sm text-neutral-400">
+        Keine Fristen vorhanden.
+      </p>
+    );
+  }
+
+  const DEADLINE_STATUS: Record<string, string> = {
+    pending: "bg-amber-50 text-amber-700",
+    completed: "bg-emerald-50 text-emerald-700",
+    overdue: "bg-red-50 text-red-700",
+  };
+
+  return (
+    <div className="space-y-2">
+      {deadlines.map((d) => (
+        <div
+          key={d.id}
+          className="flex items-center justify-between rounded-md border border-neutral-200 bg-white px-4 py-3"
+        >
+          <div>
+            <p className="text-sm font-medium text-neutral-900">{d.title}</p>
+            {d.description && (
+              <p className="mt-0.5 text-sm text-neutral-500">
+                {d.description}
+              </p>
+            )}
+          </div>
+          <div className="flex items-center gap-3">
+            <span
+              className={`rounded-full px-2 py-0.5 text-xs font-medium ${DEADLINE_STATUS[d.status] ?? "bg-neutral-100 text-neutral-500"}`}
+            >
+              {d.status}
+            </span>
+            <span className="text-sm text-neutral-500">
+              {format(new Date(d.due_date), "d. MMM yyyy", { locale: de })}
+            </span>
+          </div>
+        </div>
+      ))}
+    </div>
+  );
+}
+
+function DocumentsList({ documents }: { documents: Document[] }) {
+  if (documents.length === 0) {
+    return (
+      <p className="py-8 text-center text-sm text-neutral-400">
+        Keine Dokumente vorhanden.
+      </p>
+    );
+  }
+
+  return (
+    <div className="space-y-2">
+      {documents.map((doc) => (
+        <div
+          key={doc.id}
+          className="flex items-center justify-between rounded-md border border-neutral-200 bg-white px-4 py-3"
+        >
+          <div className="flex items-center gap-3">
+            <FileText className="h-4 w-4 text-neutral-400" />
+            <div>
+              <p className="text-sm font-medium text-neutral-900">
+                {doc.title}
+              </p>
+              <div className="flex gap-2 text-xs text-neutral-400">
+                {doc.doc_type && <span>{doc.doc_type}</span>}
+                {doc.file_size && (
+                  <span>{(doc.file_size / 1024).toFixed(0)} KB</span>
+                )}
+              </div>
+            </div>
+          </div>
+          <a
+            href={`/api/documents/${doc.id}`}
+            className="text-sm text-neutral-500 hover:text-neutral-700"
+          >
+            Herunterladen
+          </a>
+        </div>
+      ))}
+    </div>
+  );
+}

frontend/src/app/(app)/cases/new/page.tsx

@@ -0,0 +1,49 @@
+"use client";
+
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { useRouter } from "next/navigation";
+import { toast } from "sonner";
+import { api } from "@/lib/api";
+import type { Case } from "@/lib/types";
+import { CaseForm, type CaseFormData } from "@/components/cases/CaseForm";
+import { ArrowLeft } from "lucide-react";
+import Link from "next/link";
+
+export default function NewCasePage() {
+  const router = useRouter();
+  const queryClient = useQueryClient();
+
+  const mutation = useMutation({
+    mutationFn: (data: CaseFormData) => api.post<Case>("/cases", data),
+    onSuccess: (created) => {
+      queryClient.invalidateQueries({ queryKey: ["cases"] });
+      toast.success("Akte angelegt");
+      router.push(`/cases/${created.id}`);
+    },
+    onError: () => {
+      toast.error("Fehler beim Anlegen der Akte");
+    },
+  });
+
+  return (
+    <div className="mx-auto max-w-2xl">
+      <Link
+        href="/cases"
+        className="mb-4 inline-flex items-center gap-1 text-sm text-neutral-500 hover:text-neutral-700"
+      >
+        <ArrowLeft className="h-3.5 w-3.5" />
+        Zuruck zu Akten
+      </Link>
+      <h1 className="text-lg font-semibold text-neutral-900">Neue Akte</h1>
+      <p className="mt-0.5 text-sm text-neutral-500">
+        Neue Akte im System anlegen
+      </p>
+      <div className="mt-6 rounded-md border border-neutral-200 bg-white p-6">
+        <CaseForm
+          onSubmit={(data) => mutation.mutate(data)}
+          isSubmitting={mutation.isPending}
+        />
+      </div>
+    </div>
+  );
+}

frontend/src/app/(app)/cases/page.tsx

@@ -0,0 +1,172 @@
+"use client";
+
+import { useQuery } from "@tanstack/react-query";
+import { api } from "@/lib/api";
+import type { Case } from "@/lib/types";
+import Link from "next/link";
+import { useSearchParams, useRouter } from "next/navigation";
+import { Plus, Search } from "lucide-react";
+import { useState } from "react";
+
+const STATUS_OPTIONS = [
+  { value: "", label: "Alle Status" },
+  { value: "active", label: "Aktiv" },
+  { value: "pending", label: "Anhangig" },
+  { value: "closed", label: "Geschlossen" },
+  { value: "archived", label: "Archiviert" },
+];
+
+const TYPE_OPTIONS = [
+  { value: "", label: "Alle Typen" },
+  { value: "INF", label: "Verletzungsklage" },
+  { value: "REV", label: "Widerruf" },
+  { value: "CCR", label: "Einstweilige Verfugung" },
+  { value: "APP", label: "Berufung" },
+  { value: "PI", label: "Vorlaufiger Rechtsschutz" },
+  { value: "ZPO_CIVIL", label: "ZPO Zivilverfahren" },
+];
+
+const STATUS_BADGE: Record<string, string> = {
+  active: "bg-emerald-50 text-emerald-700",
+  pending: "bg-amber-50 text-amber-700",
+  closed: "bg-neutral-100 text-neutral-600",
+  archived: "bg-neutral-100 text-neutral-400",
+};
+
+export default function CasesPage() {
+  const router = useRouter();
+  const searchParams = useSearchParams();
+
+  const [search, setSearch] = useState(searchParams.get("search") ?? "");
+  const [status, setStatus] = useState(searchParams.get("status") ?? "");
+  const [type, setType] = useState(searchParams.get("type") ?? "");
+
+  const { data, isLoading } = useQuery({
+    queryKey: ["cases", { search, status, type }],
+    queryFn: () => {
+      const params = new URLSearchParams();
+      if (search) params.set("search", search);
+      if (status) params.set("status", status);
+      if (type) params.set("type", type);
+      params.set("limit", "50");
+      const qs = params.toString();
+      return api.get<{ cases: Case[]; total: number }>(
+        `/cases${qs ? `?${qs}` : ""}`,
+      );
+    },
+  });
+
+  const cases = data?.cases ?? [];
+
+  return (
+    <div>
+      <div className="flex items-center justify-between">
+        <div>
+          <h1 className="text-lg font-semibold text-neutral-900">Akten</h1>
+          <p className="mt-0.5 text-sm text-neutral-500">
+            {data ? `${data.total} Akten` : "Laden..."}
+          </p>
+        </div>
+        <Link
+          href="/cases/new"
+          className="inline-flex items-center gap-1.5 rounded-md bg-neutral-900 px-3 py-1.5 text-sm font-medium text-white hover:bg-neutral-800"
+        >
+          <Plus className="h-4 w-4" />
+          Neue Akte
+        </Link>
+      </div>
+
+      <div className="mt-4 flex items-center gap-3">
+        <div className="relative flex-1">
+          <Search className="absolute left-2.5 top-1/2 h-4 w-4 -translate-y-1/2 text-neutral-400" />
+          <input
+            type="text"
+            placeholder="Suchen nach Aktenzeichen, Titel..."
+            value={search}
+            onChange={(e) => setSearch(e.target.value)}
+            className="w-full rounded-md border border-neutral-200 bg-white py-1.5 pl-9 pr-3 text-sm outline-none focus:border-neutral-400 focus:ring-1 focus:ring-neutral-400"
+          />
+        </div>
+        <select
+          value={status}
+          onChange={(e) => setStatus(e.target.value)}
+          className="rounded-md border border-neutral-200 bg-white px-2.5 py-1.5 text-sm outline-none focus:border-neutral-400"
+        >
+          {STATUS_OPTIONS.map((o) => (
+            <option key={o.value} value={o.value}>
+              {o.label}
+            </option>
+          ))}
+        </select>
+        <select
+          value={type}
+          onChange={(e) => setType(e.target.value)}
+          className="rounded-md border border-neutral-200 bg-white px-2.5 py-1.5 text-sm outline-none focus:border-neutral-400"
+        >
+          {TYPE_OPTIONS.map((o) => (
+            <option key={o.value} value={o.value}>
+              {o.label}
+            </option>
+          ))}
+        </select>
+      </div>
+
+      <div className="mt-4">
+        {isLoading ? (
+          <div className="py-12 text-center text-sm text-neutral-400">
+            Laden...
+          </div>
+        ) : cases.length === 0 ? (
+          <div className="py-12 text-center text-sm text-neutral-400">
+            Keine Akten gefunden.
+          </div>
+        ) : (
+          <div className="overflow-hidden rounded-md border border-neutral-200 bg-white">
+            <table className="w-full text-sm">
+              <thead>
+                <tr className="border-b border-neutral-100 text-left text-xs font-medium uppercase tracking-wider text-neutral-400">
+                  <th className="px-4 py-2.5">Aktenzeichen</th>
+                  <th className="px-4 py-2.5">Titel</th>
+                  <th className="px-4 py-2.5">Typ</th>
+                  <th className="px-4 py-2.5">Gericht</th>
+                  <th className="px-4 py-2.5">Status</th>
+                  <th className="px-4 py-2.5">Erstellt</th>
+                </tr>
+              </thead>
+              <tbody className="divide-y divide-neutral-100">
+                {cases.map((c) => (
+                  <tr
+                    key={c.id}
+                    onClick={() => router.push(`/cases/${c.id}`)}
+                    className="cursor-pointer hover:bg-neutral-50"
+                  >
+                    <td className="px-4 py-2.5 font-medium text-neutral-900">
+                      {c.case_number}
+                    </td>
+                    <td className="px-4 py-2.5 text-neutral-700">{c.title}</td>
+                    <td className="px-4 py-2.5 text-neutral-500">
+                      {c.case_type ?? "-"}
+                    </td>
+                    <td className="px-4 py-2.5 text-neutral-500">
+                      {c.court ?? "-"}
+                    </td>
+                    <td className="px-4 py-2.5">
+                      <span
+                        className={`inline-block rounded-full px-2 py-0.5 text-xs font-medium ${STATUS_BADGE[c.status] ?? "bg-neutral-100 text-neutral-500"}`}
+                      >
+                        {c.status}
+                      </span>
+                    </td>
+                    <td className="px-4 py-2.5 text-neutral-400">
+                      {new Date(c.created_at).toLocaleDateString("de-DE")}
+                    </td>
+                  </tr>
+                ))}
+              </tbody>
+            </table>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}

frontend/src/app/(app)/layout.tsx

@@ -0,0 +1,20 @@
+import { Sidebar } from "@/components/layout/Sidebar";
+import { Header } from "@/components/layout/Header";
+
+export const dynamic = "force-dynamic";
+
+export default function AppLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  return (
+    <div className="flex h-screen overflow-hidden bg-neutral-50">
+      <Sidebar />
+      <div className="flex flex-1 flex-col overflow-hidden">
+        <Header />
+        <main className="flex-1 overflow-y-auto p-6">{children}</main>
+      </div>
+    </div>
+  );
+}

frontend/src/app/(app)/page.tsx

@@ -0,0 +1,10 @@
+export default function DashboardPage() {
+  return (
+    <div>
+      <h1 className="text-lg font-semibold text-neutral-900">Dashboard</h1>
+      <p className="mt-1 text-sm text-neutral-500">
+        Willkommen bei KanzlAI
+      </p>
+    </div>
+  );
+}

frontend/src/app/(auth)/callback/page.tsx

@@ -0,0 +1,25 @@
+"use client";
+
+import { createClient } from "@/lib/supabase/client";
+import { useRouter } from "next/navigation";
+import { useEffect } from "react";
+
+export default function CallbackPage() {
+  const router = useRouter();
+  const supabase = createClient();
+
+  useEffect(() => {
+    supabase.auth.onAuthStateChange((event) => {
+      if (event === "SIGNED_IN") {
+        router.push("/");
+        router.refresh();
+      }
+    });
+  }, [router, supabase.auth]);
+
+  return (
+    <div className="flex min-h-screen items-center justify-center bg-neutral-50">
+      <p className="text-sm text-neutral-500">Authentifizierung...</p>
+    </div>
+  );
+}

frontend/src/app/(auth)/layout.tsx

@@ -0,0 +1,9 @@
+export const dynamic = "force-dynamic";
+
+export default function AuthLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  return <>{children}</>;
+}

frontend/src/app/(auth)/login/page.tsx

@@ -0,0 +1,189 @@
+"use client";
+
+import { createClient } from "@/lib/supabase/client";
+import { useRouter } from "next/navigation";
+import { useState } from "react";
+
+export default function LoginPage() {
+  const [email, setEmail] = useState("");
+  const [password, setPassword] = useState("");
+  const [mode, setMode] = useState<"password" | "magic">("password");
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [magicSent, setMagicSent] = useState(false);
+  const router = useRouter();
+  const supabase = createClient();
+
+  async function handlePasswordLogin(e: React.FormEvent) {
+    e.preventDefault();
+    setLoading(true);
+    setError(null);
+
+    const { error } = await supabase.auth.signInWithPassword({
+      email,
+      password,
+    });
+
+    if (error) {
+      setError(error.message);
+      setLoading(false);
+      return;
+    }
+
+    router.push("/");
+    router.refresh();
+  }
+
+  async function handleMagicLink(e: React.FormEvent) {
+    e.preventDefault();
+    setLoading(true);
+    setError(null);
+
+    const { error } = await supabase.auth.signInWithOtp({
+      email,
+      options: {
+        emailRedirectTo: `${window.location.origin}/callback`,
+      },
+    });
+
+    if (error) {
+      setError(error.message);
+      setLoading(false);
+      return;
+    }
+
+    setMagicSent(true);
+    setLoading(false);
+  }
+
+  if (magicSent) {
+    return (
+      <div className="flex min-h-screen items-center justify-center bg-neutral-50">
+        <div className="w-full max-w-sm space-y-6 rounded-lg border border-neutral-200 bg-white p-8">
+          <div className="text-center">
+            <h1 className="text-lg font-semibold text-neutral-900">
+              Link gesendet
+            </h1>
+            <p className="mt-2 text-sm text-neutral-500">
+              Wir haben einen Login-Link an{" "}
+              <span className="font-medium text-neutral-700">{email}</span>{" "}
+              gesendet. Bitte pruefen Sie Ihren Posteingang.
+            </p>
+          </div>
+          <button
+            onClick={() => setMagicSent(false)}
+            className="w-full text-center text-sm text-neutral-500 hover:text-neutral-700"
+          >
+            Zurueck zum Login
+          </button>
+        </div>
+      </div>
+    );
+  }
+
+  return (
+    <div className="flex min-h-screen items-center justify-center bg-neutral-50">
+      <div className="w-full max-w-sm space-y-6 rounded-lg border border-neutral-200 bg-white p-8">
+        <div className="text-center">
+          <h1 className="text-lg font-semibold text-neutral-900">
+            KanzlAI
+          </h1>
+          <p className="mt-1 text-sm text-neutral-500">
+            Melden Sie sich an
+          </p>
+        </div>
+
+        <div className="flex rounded-md border border-neutral-200 bg-neutral-50 p-0.5">
+          <button
+            onClick={() => setMode("password")}
+            className={`flex-1 rounded-md px-3 py-1.5 text-sm font-medium transition-colors ${
+              mode === "password"
+                ? "bg-white text-neutral-900 shadow-sm"
+                : "text-neutral-500 hover:text-neutral-700"
+            }`}
+          >
+            Passwort
+          </button>
+          <button
+            onClick={() => setMode("magic")}
+            className={`flex-1 rounded-md px-3 py-1.5 text-sm font-medium transition-colors ${
+              mode === "magic"
+                ? "bg-white text-neutral-900 shadow-sm"
+                : "text-neutral-500 hover:text-neutral-700"
+            }`}
+          >
+            Magic Link
+          </button>
+        </div>
+
+        <form
+          onSubmit={mode === "password" ? handlePasswordLogin : handleMagicLink}
+          className="space-y-4"
+        >
+          <div>
+            <label
+              htmlFor="email"
+              className="block text-sm font-medium text-neutral-700"
+            >
+              E-Mail
+            </label>
+            <input
+              id="email"
+              type="email"
+              value={email}
+              onChange={(e) => setEmail(e.target.value)}
+              required
+              className="mt-1 block w-full rounded-md border border-neutral-300 px-3 py-2 text-sm placeholder-neutral-400 focus:border-neutral-900 focus:outline-none focus:ring-1 focus:ring-neutral-900"
+              placeholder="anwalt@kanzlei.de"
+            />
+          </div>
+
+          {mode === "password" && (
+            <div>
+              <label
+                htmlFor="password"
+                className="block text-sm font-medium text-neutral-700"
+              >
+                Passwort
+              </label>
+              <input
+                id="password"
+                type="password"
+                value={password}
+                onChange={(e) => setPassword(e.target.value)}
+                required
+                className="mt-1 block w-full rounded-md border border-neutral-300 px-3 py-2 text-sm placeholder-neutral-400 focus:border-neutral-900 focus:outline-none focus:ring-1 focus:ring-neutral-900"
+              />
+            </div>
+          )}
+
+          {error && (
+            <p className="text-sm text-red-600">{error}</p>
+          )}
+
+          <button
+            type="submit"
+            disabled={loading}
+            className="w-full rounded-md bg-neutral-900 px-4 py-2 text-sm font-medium text-white hover:bg-neutral-800 focus:outline-none focus:ring-2 focus:ring-neutral-900 focus:ring-offset-2 disabled:opacity-50"
+          >
+            {loading
+              ? "..."
+              : mode === "password"
+                ? "Anmelden"
+                : "Link senden"}
+          </button>
+        </form>
+
+        <p className="text-center text-sm text-neutral-500">
+          Noch kein Konto?{" "}
+          <a
+            href="/register"
+            className="font-medium text-neutral-900 hover:underline"
+          >
+            Registrieren
+          </a>
+        </p>
+      </div>
+    </div>
+  );
+}

frontend/src/app/(auth)/register/page.tsx

@@ -0,0 +1,151 @@
+"use client";
+
+import { createClient } from "@/lib/supabase/client";
+import { api } from "@/lib/api";
+import { useRouter } from "next/navigation";
+import { useState } from "react";
+
+export default function RegisterPage() {
+  const [email, setEmail] = useState("");
+  const [password, setPassword] = useState("");
+  const [firmName, setFirmName] = useState("");
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const router = useRouter();
+  const supabase = createClient();
+
+  async function handleRegister(e: React.FormEvent) {
+    e.preventDefault();
+    setLoading(true);
+    setError(null);
+
+    // 1. Create auth user
+    const { data, error: authError } = await supabase.auth.signUp({
+      email,
+      password,
+      options: {
+        emailRedirectTo: `${window.location.origin}/callback`,
+      },
+    });
+
+    if (authError) {
+      setError(authError.message);
+      setLoading(false);
+      return;
+    }
+
+    // 2. Create tenant via backend (the backend adds the user as owner)
+    if (data.session) {
+      try {
+        await api.post("/tenants", { name: firmName });
+      } catch (err: unknown) {
+        const apiErr = err as { error?: string };
+        setError(apiErr.error || "Kanzlei konnte nicht erstellt werden");
+        setLoading(false);
+        return;
+      }
+
+      router.push("/");
+      router.refresh();
+    } else {
+      // Email confirmation required
+      router.push("/login");
+    }
+
+    setLoading(false);
+  }
+
+  return (
+    <div className="flex min-h-screen items-center justify-center bg-neutral-50">
+      <div className="w-full max-w-sm space-y-6 rounded-lg border border-neutral-200 bg-white p-8">
+        <div className="text-center">
+          <h1 className="text-lg font-semibold text-neutral-900">
+            KanzlAI
+          </h1>
+          <p className="mt-1 text-sm text-neutral-500">
+            Erstellen Sie Ihr Konto
+          </p>
+        </div>
+
+        <form onSubmit={handleRegister} className="space-y-4">
+          <div>
+            <label
+              htmlFor="firm"
+              className="block text-sm font-medium text-neutral-700"
+            >
+              Kanzleiname
+            </label>
+            <input
+              id="firm"
+              type="text"
+              value={firmName}
+              onChange={(e) => setFirmName(e.target.value)}
+              required
+              className="mt-1 block w-full rounded-md border border-neutral-300 px-3 py-2 text-sm placeholder-neutral-400 focus:border-neutral-900 focus:outline-none focus:ring-1 focus:ring-neutral-900"
+              placeholder="Muster & Partner Rechtsanwaelte"
+            />
+          </div>
+
+          <div>
+            <label
+              htmlFor="email"
+              className="block text-sm font-medium text-neutral-700"
+            >
+              E-Mail
+            </label>
+            <input
+              id="email"
+              type="email"
+              value={email}
+              onChange={(e) => setEmail(e.target.value)}
+              required
+              className="mt-1 block w-full rounded-md border border-neutral-300 px-3 py-2 text-sm placeholder-neutral-400 focus:border-neutral-900 focus:outline-none focus:ring-1 focus:ring-neutral-900"
+              placeholder="anwalt@kanzlei.de"
+            />
+          </div>
+
+          <div>
+            <label
+              htmlFor="password"
+              className="block text-sm font-medium text-neutral-700"
+            >
+              Passwort
+            </label>
+            <input
+              id="password"
+              type="password"
+              value={password}
+              onChange={(e) => setPassword(e.target.value)}
+              required
+              minLength={8}
+              className="mt-1 block w-full rounded-md border border-neutral-300 px-3 py-2 text-sm placeholder-neutral-400 focus:border-neutral-900 focus:outline-none focus:ring-1 focus:ring-neutral-900"
+            />
+            <p className="mt-1 text-xs text-neutral-400">Mindestens 8 Zeichen</p>
+          </div>
+
+          {error && (
+            <p className="text-sm text-red-600">{error}</p>
+          )}
+
+          <button
+            type="submit"
+            disabled={loading}
+            className="w-full rounded-md bg-neutral-900 px-4 py-2 text-sm font-medium text-white hover:bg-neutral-800 focus:outline-none focus:ring-2 focus:ring-neutral-900 focus:ring-offset-2 disabled:opacity-50"
+          >
+            {loading ? "..." : "Konto erstellen"}
+          </button>
+        </form>
+
+        <p className="text-center text-sm text-neutral-500">
+          Bereits registriert?{" "}
+          <a
+            href="/login"
+            className="font-medium text-neutral-900 hover:underline"
+          >
+            Anmelden
+          </a>
+        </p>
+      </div>
+    </div>
+  );
+}

frontend/src/app/globals.css

@@ -1,26 +1,11 @@
 @import "tailwindcss";
 
-:root {
-  --background: #ffffff;
-  --foreground: #171717;
-}
-
 @theme inline {
-  --color-background: var(--background);
-  --color-foreground: var(--foreground);
   --font-sans: var(--font-geist-sans);
   --font-mono: var(--font-geist-mono);
 }
 
-@media (prefers-color-scheme: dark) {
-  :root {
-    --background: #0a0a0a;
-    --foreground: #ededed;
-  }
-}
-
 body {
-  background: var(--background);
+  -webkit-font-smoothing: antialiased;
-  color: var(--foreground);
+  -moz-osx-font-smoothing: grayscale;
-  font-family: Arial, Helvetica, sans-serif;
 }

frontend/src/app/layout.tsx

@@ -1,5 +1,6 @@
 import type { Metadata } from "next";
 import { Geist, Geist_Mono } from "next/font/google";
+import { Providers } from "@/components/Providers";
 import "./globals.css";
 
 const geistSans = Geist({
@@ -13,7 +14,7 @@ const geistMono = Geist_Mono({
 });
 
 export const metadata: Metadata = {
-  title: "KanzlAI-mGMT",
+  title: "KanzlAI",
   description: "Kanzleimanagement online",
 };
 
@@ -23,11 +24,11 @@ export default function RootLayout({
   children: React.ReactNode;
 }>) {
   return (
-    <html lang="en">
+    <html lang="de">
       <body
-        className={`${geistSans.variable} ${geistMono.variable} antialiased`}
+        className={`${geistSans.variable} ${geistMono.variable} font-sans antialiased`}
       >
-        {children}
+        <Providers>{children}</Providers>
       </body>
     </html>
   );

frontend/src/app/page.tsx

@@ -1,7 +0,0 @@
-export default function Home() {
-  return (
-    <main className="flex min-h-screen items-center justify-center">
-      <h1 className="text-4xl font-bold">KanzlAI-mGMT</h1>
-    </main>
-  );
-}

frontend/src/components/Providers.tsx

@@ -0,0 +1,26 @@
+"use client";
+
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { Toaster } from "sonner";
+import { useState } from "react";
+
+export function Providers({ children }: { children: React.ReactNode }) {
+  const [queryClient] = useState(
+    () =>
+      new QueryClient({
+        defaultOptions: {
+          queries: {
+            staleTime: 30 * 1000,
+            retry: 1,
+          },
+        },
+      }),
+  );
+
+  return (
+    <QueryClientProvider client={queryClient}>
+      {children}
+      <Toaster position="bottom-right" richColors />
+    </QueryClientProvider>
+  );
+}

frontend/src/components/cases/CaseForm.tsx

@@ -0,0 +1,165 @@
+"use client";
+
+import { useState } from "react";
+
+const TYPE_OPTIONS = [
+  { value: "", label: "-- Typ wahlen --" },
+  { value: "INF", label: "Verletzungsklage (INF)" },
+  { value: "REV", label: "Widerruf (REV)" },
+  { value: "CCR", label: "Einstweilige Verfugung (CCR)" },
+  { value: "APP", label: "Berufung (APP)" },
+  { value: "PI", label: "Vorlaufiger Rechtsschutz (PI)" },
+  { value: "ZPO_CIVIL", label: "ZPO Zivilverfahren" },
+];
+
+export interface CaseFormData {
+  case_number: string;
+  title: string;
+  case_type?: string;
+  court?: string;
+  court_ref?: string;
+  status: string;
+}
+
+interface CaseFormProps {
+  initialData?: Partial<CaseFormData>;
+  onSubmit: (data: CaseFormData) => void;
+  isSubmitting?: boolean;
+  submitLabel?: string;
+}
+
+export function CaseForm({
+  initialData,
+  onSubmit,
+  isSubmitting,
+  submitLabel = "Akte anlegen",
+}: CaseFormProps) {
+  const [form, setForm] = useState<CaseFormData>({
+    case_number: initialData?.case_number ?? "",
+    title: initialData?.title ?? "",
+    case_type: initialData?.case_type ?? "",
+    court: initialData?.court ?? "",
+    court_ref: initialData?.court_ref ?? "",
+    status: initialData?.status ?? "active",
+  });
+
+  function handleSubmit(e: React.FormEvent) {
+    e.preventDefault();
+    const data: CaseFormData = {
+      ...form,
+      case_type: form.case_type || undefined,
+      court: form.court || undefined,
+      court_ref: form.court_ref || undefined,
+    };
+    onSubmit(data);
+  }
+
+  function update(field: keyof CaseFormData, value: string) {
+    setForm((prev) => ({ ...prev, [field]: value }));
+  }
+
+  const inputClass =
+    "w-full rounded-md border border-neutral-200 bg-white px-3 py-1.5 text-sm outline-none focus:border-neutral-400 focus:ring-1 focus:ring-neutral-400";
+
+  return (
+    <form onSubmit={handleSubmit} className="space-y-4">
+      <div className="grid grid-cols-2 gap-4">
+        <div>
+          <label className="mb-1 block text-sm font-medium text-neutral-700">
+            Aktenzeichen *
+          </label>
+          <input
+            type="text"
+            required
+            value={form.case_number}
+            onChange={(e) => update("case_number", e.target.value)}
+            placeholder="z.B. 2026/001"
+            className={inputClass}
+          />
+        </div>
+        <div>
+          <label className="mb-1 block text-sm font-medium text-neutral-700">
+            Status
+          </label>
+          <select
+            value={form.status}
+            onChange={(e) => update("status", e.target.value)}
+            className={inputClass}
+          >
+            <option value="active">Aktiv</option>
+            <option value="pending">Anhangig</option>
+            <option value="closed">Geschlossen</option>
+          </select>
+        </div>
+      </div>
+
+      <div>
+        <label className="mb-1 block text-sm font-medium text-neutral-700">
+          Titel *
+        </label>
+        <input
+          type="text"
+          required
+          value={form.title}
+          onChange={(e) => update("title", e.target.value)}
+          placeholder="Bezeichnung der Akte"
+          className={inputClass}
+        />
+      </div>
+
+      <div className="grid grid-cols-2 gap-4">
+        <div>
+          <label className="mb-1 block text-sm font-medium text-neutral-700">
+            Verfahrensart
+          </label>
+          <select
+            value={form.case_type}
+            onChange={(e) => update("case_type", e.target.value)}
+            className={inputClass}
+          >
+            {TYPE_OPTIONS.map((o) => (
+              <option key={o.value} value={o.value}>
+                {o.label}
+              </option>
+            ))}
+          </select>
+        </div>
+        <div>
+          <label className="mb-1 block text-sm font-medium text-neutral-700">
+            Gericht
+          </label>
+          <input
+            type="text"
+            value={form.court}
+            onChange={(e) => update("court", e.target.value)}
+            placeholder="z.B. UPC Munich Central Division"
+            className={inputClass}
+          />
+        </div>
+      </div>
+
+      <div>
+        <label className="mb-1 block text-sm font-medium text-neutral-700">
+          Gerichtliches Aktenzeichen
+        </label>
+        <input
+          type="text"
+          value={form.court_ref}
+          onChange={(e) => update("court_ref", e.target.value)}
+          placeholder="z.B. UPC_CFI_123/2026"
+          className={inputClass}
+        />
+      </div>
+
+      <div className="flex justify-end pt-2">
+        <button
+          type="submit"
+          disabled={isSubmitting}
+          className="rounded-md bg-neutral-900 px-4 py-1.5 text-sm font-medium text-white hover:bg-neutral-800 disabled:opacity-50"
+        >
+          {isSubmitting ? "Speichern..." : submitLabel}
+        </button>
+      </div>
+    </form>
+  );
+}

frontend/src/components/cases/CaseTimeline.tsx

@@ -0,0 +1,60 @@
+"use client";
+
+import type { CaseEvent } from "@/lib/types";
+import { format } from "date-fns";
+import { de } from "date-fns/locale";
+
+const EVENT_ICONS: Record<string, string> = {
+  case_created: "bg-emerald-500",
+  status_changed: "bg-amber-500",
+  party_added: "bg-blue-500",
+  case_archived: "bg-neutral-400",
+  document_uploaded: "bg-violet-500",
+  deadline_created: "bg-red-500",
+};
+
+interface CaseTimelineProps {
+  events: CaseEvent[];
+}
+
+export function CaseTimeline({ events }: CaseTimelineProps) {
+  if (events.length === 0) {
+    return (
+      <p className="py-8 text-center text-sm text-neutral-400">
+        Keine Ereignisse vorhanden.
+      </p>
+    );
+  }
+
+  return (
+    <div className="relative space-y-0">
+      {events.map((event, i) => (
+        <div key={event.id} className="relative flex gap-3 pb-6">
+          {i < events.length - 1 && (
+            <div className="absolute left-[7px] top-4 h-full w-px bg-neutral-200" />
+          )}
+          <div
+            className={`mt-1 h-[15px] w-[15px] shrink-0 rounded-full border-2 border-white ${EVENT_ICONS[event.event_type ?? ""] ?? "bg-neutral-300"}`}
+          />
+          <div className="min-w-0 flex-1">
+            <p className="text-sm font-medium text-neutral-900">
+              {event.title}
+            </p>
+            {event.description && (
+              <p className="mt-0.5 text-sm text-neutral-500">
+                {event.description}
+              </p>
+            )}
+            <p className="mt-1 text-xs text-neutral-400">
+              {format(
+                new Date(event.event_date ?? event.created_at),
+                "d. MMM yyyy, HH:mm",
+                { locale: de },
+              )}
+            </p>
+          </div>
+        </div>
+      ))}
+    </div>
+  );
+}

frontend/src/components/cases/PartyList.tsx

@@ -0,0 +1,182 @@
+"use client";
+
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { useState } from "react";
+import { toast } from "sonner";
+import { api } from "@/lib/api";
+import type { Party } from "@/lib/types";
+import { Plus, Trash2, X } from "lucide-react";
+
+interface PartyListProps {
+  caseId: string;
+  parties: Party[];
+}
+
+interface PartyFormData {
+  name: string;
+  role: string;
+  representative: string;
+}
+
+const ROLE_OPTIONS = [
+  "Klager",
+  "Beklagter",
+  "Nebenintervenient",
+  "Patentinhaber",
+  "Streithelfer",
+];
+
+export function PartyList({ caseId, parties }: PartyListProps) {
+  const queryClient = useQueryClient();
+  const [showForm, setShowForm] = useState(false);
+  const [form, setForm] = useState<PartyFormData>({
+    name: "",
+    role: "",
+    representative: "",
+  });
+
+  const addMutation = useMutation({
+    mutationFn: (data: PartyFormData) =>
+      api.post<Party>(`/cases/${caseId}/parties`, {
+        name: data.name,
+        role: data.role || undefined,
+        representative: data.representative || undefined,
+      }),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["case", caseId] });
+      toast.success("Partei hinzugefugt");
+      setShowForm(false);
+      setForm({ name: "", role: "", representative: "" });
+    },
+    onError: () => toast.error("Fehler beim Hinzufugen"),
+  });
+
+  const deleteMutation = useMutation({
+    mutationFn: (partyId: string) => api.delete(`/parties/${partyId}`),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["case", caseId] });
+      toast.success("Partei entfernt");
+    },
+    onError: () => toast.error("Fehler beim Entfernen"),
+  });
+
+  const inputClass =
+    "w-full rounded-md border border-neutral-200 bg-white px-3 py-1.5 text-sm outline-none focus:border-neutral-400 focus:ring-1 focus:ring-neutral-400";
+
+  return (
+    <div>
+      <div className="flex items-center justify-between">
+        <h3 className="text-sm font-medium text-neutral-700">
+          Parteien ({parties.length})
+        </h3>
+        {!showForm && (
+          <button
+            onClick={() => setShowForm(true)}
+            className="inline-flex items-center gap-1 text-sm text-neutral-500 hover:text-neutral-700"
+          >
+            <Plus className="h-3.5 w-3.5" />
+            Hinzufugen
+          </button>
+        )}
+      </div>
+
+      {parties.length === 0 && !showForm && (
+        <p className="mt-4 py-4 text-center text-sm text-neutral-400">
+          Keine Parteien vorhanden.
+        </p>
+      )}
+
+      <div className="mt-3 space-y-2">
+        {parties.map((party) => (
+          <div
+            key={party.id}
+            className="flex items-center justify-between rounded-md border border-neutral-200 bg-white px-4 py-2.5"
+          >
+            <div>
+              <p className="text-sm font-medium text-neutral-900">
+                {party.name}
+              </p>
+              <div className="mt-0.5 flex gap-3 text-xs text-neutral-500">
+                {party.role && <span>{party.role}</span>}
+                {party.representative && (
+                  <span>Vertreter: {party.representative}</span>
+                )}
+              </div>
+            </div>
+            <button
+              onClick={() => deleteMutation.mutate(party.id)}
+              className="rounded p-1 text-neutral-300 hover:bg-neutral-100 hover:text-red-500"
+              title="Partei entfernen"
+            >
+              <Trash2 className="h-3.5 w-3.5" />
+            </button>
+          </div>
+        ))}
+      </div>
+
+      {showForm && (
+        <div className="mt-3 rounded-md border border-neutral-200 bg-neutral-50 p-4">
+          <div className="flex items-center justify-between">
+            <span className="text-sm font-medium text-neutral-700">
+              Neue Partei
+            </span>
+            <button
+              onClick={() => setShowForm(false)}
+              className="text-neutral-400 hover:text-neutral-600"
+            >
+              <X className="h-4 w-4" />
+            </button>
+          </div>
+          <form
+            onSubmit={(e) => {
+              e.preventDefault();
+              addMutation.mutate(form);
+            }}
+            className="mt-3 space-y-3"
+          >
+            <input
+              type="text"
+              required
+              placeholder="Name der Partei"
+              value={form.name}
+              onChange={(e) => setForm({ ...form, name: e.target.value })}
+              className={inputClass}
+            />
+            <div className="grid grid-cols-2 gap-3">
+              <select
+                value={form.role}
+                onChange={(e) => setForm({ ...form, role: e.target.value })}
+                className={inputClass}
+              >
+                <option value="">-- Rolle --</option>
+                {ROLE_OPTIONS.map((r) => (
+                  <option key={r} value={r}>
+                    {r}
+                  </option>
+                ))}
+              </select>
+              <input
+                type="text"
+                placeholder="Vertreter / Anwalt"
+                value={form.representative}
+                onChange={(e) =>
+                  setForm({ ...form, representative: e.target.value })
+                }
+                className={inputClass}
+              />
+            </div>
+            <div className="flex justify-end">
+              <button
+                type="submit"
+                disabled={addMutation.isPending}
+                className="rounded-md bg-neutral-900 px-3 py-1.5 text-sm font-medium text-white hover:bg-neutral-800 disabled:opacity-50"
+              >
+                {addMutation.isPending ? "..." : "Hinzufugen"}
+              </button>
+            </div>
+          </form>
+        </div>
+      )}
+    </div>
+  );
+}

frontend/src/components/layout/Header.tsx

@@ -0,0 +1,44 @@
+"use client";
+
+import { createClient } from "@/lib/supabase/client";
+import { TenantSwitcher } from "./TenantSwitcher";
+import { LogOut } from "lucide-react";
+import { useRouter } from "next/navigation";
+import { useEffect, useState } from "react";
+
+export function Header() {
+  const [email, setEmail] = useState<string | null>(null);
+  const router = useRouter();
+  const supabase = createClient();
+
+  useEffect(() => {
+    supabase.auth.getUser().then(({ data: { user } }) => {
+      setEmail(user?.email ?? null);
+    });
+  }, [supabase.auth]);
+
+  async function handleLogout() {
+    await supabase.auth.signOut();
+    router.push("/login");
+    router.refresh();
+  }
+
+  return (
+    <header className="flex h-14 items-center justify-between border-b border-neutral-200 bg-white px-4">
+      <div />
+      <div className="flex items-center gap-3">
+        <TenantSwitcher />
+        {email && (
+          <span className="text-sm text-neutral-500">{email}</span>
+        )}
+        <button
+          onClick={handleLogout}
+          title="Abmelden"
+          className="rounded-md p-1.5 text-neutral-400 hover:bg-neutral-100 hover:text-neutral-600"
+        >
+          <LogOut className="h-4 w-4" />
+        </button>
+      </div>
+    </header>
+  );
+}

frontend/src/components/layout/Sidebar.tsx

@@ -0,0 +1,55 @@
+"use client";
+
+import Link from "next/link";
+import { usePathname } from "next/navigation";
+import {
+  LayoutDashboard,
+  FolderOpen,
+  Clock,
+  Calendar,
+  Brain,
+  Settings,
+} from "lucide-react";
+
+const navigation = [
+  { name: "Dashboard", href: "/", icon: LayoutDashboard },
+  { name: "Akten", href: "/cases", icon: FolderOpen },
+  { name: "Fristen", href: "/fristen", icon: Clock },
+  { name: "Termine", href: "/termine", icon: Calendar },
+  { name: "AI Analyse", href: "/ai", icon: Brain },
+  { name: "Einstellungen", href: "/einstellungen", icon: Settings },
+];
+
+export function Sidebar() {
+  const pathname = usePathname();
+
+  return (
+    <aside className="flex h-full w-56 flex-col border-r border-neutral-200 bg-white">
+      <div className="flex h-14 items-center border-b border-neutral-200 px-4">
+        <span className="text-sm font-semibold text-neutral-900">KanzlAI</span>
+      </div>
+      <nav className="flex-1 space-y-0.5 p-2">
+        {navigation.map((item) => {
+          const isActive =
+            item.href === "/"
+              ? pathname === "/"
+              : pathname.startsWith(item.href);
+          return (
+            <Link
+              key={item.href}
+              href={item.href}
+              className={`flex items-center gap-2.5 rounded-md px-2.5 py-1.5 text-sm transition-colors ${
+                isActive
+                  ? "bg-neutral-100 font-medium text-neutral-900"
+                  : "text-neutral-600 hover:bg-neutral-50 hover:text-neutral-900"
+              }`}
+            >
+              <item.icon className="h-4 w-4 shrink-0" />
+              {item.name}
+            </Link>
+          );
+        })}
+      </nav>
+    </aside>
+  );
+}

frontend/src/components/layout/TenantSwitcher.tsx

@@ -0,0 +1,79 @@
+"use client";
+
+import { api } from "@/lib/api";
+import type { TenantWithRole } from "@/lib/types";
+import { ChevronsUpDown } from "lucide-react";
+import { useEffect, useRef, useState } from "react";
+
+export function TenantSwitcher() {
+  const [tenants, setTenants] = useState<TenantWithRole[]>([]);
+  const [current, setCurrent] = useState<TenantWithRole | null>(null);
+  const [open, setOpen] = useState(false);
+  const ref = useRef<HTMLDivElement>(null);
+
+  useEffect(() => {
+    api.get<TenantWithRole[]>("/tenants").then((data) => {
+      setTenants(data);
+      const savedId = localStorage.getItem("kanzlai_tenant_id");
+      const match = data.find((t) => t.id === savedId) || data[0];
+      if (match) {
+        setCurrent(match);
+        localStorage.setItem("kanzlai_tenant_id", match.id);
+      }
+    }).catch(() => {
+      // Not authenticated or no tenants
+    });
+  }, []);
+
+  useEffect(() => {
+    function handleClick(e: MouseEvent) {
+      if (ref.current && !ref.current.contains(e.target as Node)) {
+        setOpen(false);
+      }
+    }
+    document.addEventListener("mousedown", handleClick);
+    return () => document.removeEventListener("mousedown", handleClick);
+  }, []);
+
+  function switchTenant(tenant: TenantWithRole) {
+    setCurrent(tenant);
+    localStorage.setItem("kanzlai_tenant_id", tenant.id);
+    setOpen(false);
+    window.location.reload();
+  }
+
+  if (!current) return null;
+
+  return (
+    <div ref={ref} className="relative">
+      <button
+        onClick={() => setOpen(!open)}
+        className="flex items-center gap-1.5 rounded-md border border-neutral-200 bg-white px-2.5 py-1.5 text-sm text-neutral-700 hover:bg-neutral-50"
+      >
+        <span className="max-w-[160px] truncate">{current.name}</span>
+        <ChevronsUpDown className="h-3.5 w-3.5 text-neutral-400" />
+      </button>
+
+      {open && tenants.length > 1 && (
+        <div className="absolute right-0 top-full z-50 mt-1 w-56 rounded-md border border-neutral-200 bg-white py-1 shadow-lg">
+          {tenants.map((tenant) => (
+            <button
+              key={tenant.id}
+              onClick={() => switchTenant(tenant)}
+              className={`flex w-full items-center px-3 py-1.5 text-left text-sm transition-colors ${
+                tenant.id === current.id
+                  ? "bg-neutral-50 font-medium text-neutral-900"
+                  : "text-neutral-600 hover:bg-neutral-50"
+              }`}
+            >
+              <span className="truncate">{tenant.name}</span>
+              <span className="ml-auto text-xs text-neutral-400">
+                {tenant.role}
+              </span>
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}

frontend/src/lib/api.ts

@@ -0,0 +1,77 @@
+import { createClient } from "@/lib/supabase/client";
+import type { ApiError } from "@/lib/types";
+
+class ApiClient {
+  private baseUrl = "/api";
+
+  private async getHeaders(): Promise<HeadersInit> {
+    const supabase = createClient();
+    const {
+      data: { session },
+    } = await supabase.auth.getSession();
+
+    const headers: HeadersInit = {
+      "Content-Type": "application/json",
+    };
+
+    if (session?.access_token) {
+      headers["Authorization"] = `Bearer ${session.access_token}`;
+    }
+
+    const tenantId = typeof window !== "undefined"
+      ? localStorage.getItem("kanzlai_tenant_id")
+      : null;
+    if (tenantId) {
+      headers["X-Tenant-ID"] = tenantId;
+    }
+
+    return headers;
+  }
+
+  private async request<T>(
+    path: string,
+    options: RequestInit = {},
+  ): Promise<T> {
+    const headers = await this.getHeaders();
+    const res = await fetch(`${this.baseUrl}${path}`, {
+      ...options,
+      headers: { ...headers, ...options.headers },
+    });
+
+    if (!res.ok) {
+      const body = await res.json().catch(() => ({}));
+      const err: ApiError = {
+        error: body.error || res.statusText,
+        status: res.status,
+      };
+      throw err;
+    }
+
+    if (res.status === 204) return undefined as T;
+    return res.json();
+  }
+
+  get<T>(path: string) {
+    return this.request<T>(path, { method: "GET" });
+  }
+
+  post<T>(path: string, body?: unknown) {
+    return this.request<T>(path, {
+      method: "POST",
+      body: body ? JSON.stringify(body) : undefined,
+    });
+  }
+
+  put<T>(path: string, body?: unknown) {
+    return this.request<T>(path, {
+      method: "PUT",
+      body: body ? JSON.stringify(body) : undefined,
+    });
+  }
+
+  delete<T>(path: string) {
+    return this.request<T>(path, { method: "DELETE" });
+  }
+}
+
+export const api = new ApiClient();

frontend/src/lib/supabase/client.ts

@@ -0,0 +1,8 @@
+import { createBrowserClient } from "@supabase/ssr";
+
+export function createClient() {
+  return createBrowserClient(
+    process.env.NEXT_PUBLIC_SUPABASE_URL!,
+    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
+  );
+}

frontend/src/lib/supabase/server.ts

@@ -0,0 +1,29 @@
+import { createServerClient } from "@supabase/ssr";
+import { cookies } from "next/headers";
+
+export async function createClient() {
+  const cookieStore = await cookies();
+
+  return createServerClient(
+    process.env.NEXT_PUBLIC_SUPABASE_URL!,
+    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
+    {
+      cookies: {
+        getAll() {
+          return cookieStore.getAll();
+        },
+        setAll(cookiesToSet) {
+          try {
+            cookiesToSet.forEach(({ name, value, options }) =>
+              cookieStore.set(name, value, options),
+            );
+          } catch {
+            // setAll is called from Server Components where cookies
+            // cannot be set. This is safe to ignore when middleware
+            // handles the session refresh.
+          }
+        },
+      },
+    },
+  );
+}

frontend/src/lib/types.ts

@@ -0,0 +1,117 @@
+export interface Tenant {
+  id: string;
+  name: string;
+  slug: string;
+  settings: Record<string, unknown>;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface TenantWithRole extends Tenant {
+  role: string;
+}
+
+export interface UserTenant {
+  user_id: string;
+  tenant_id: string;
+  role: string;
+  created_at: string;
+}
+
+export interface Case {
+  id: string;
+  tenant_id: string;
+  case_number: string;
+  title: string;
+  case_type?: string;
+  court?: string;
+  court_ref?: string;
+  status: string;
+  ai_summary?: string;
+  metadata: Record<string, unknown>;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface Party {
+  id: string;
+  tenant_id: string;
+  case_id: string;
+  name: string;
+  role?: string;
+  representative?: string;
+  contact_info: Record<string, unknown>;
+}
+
+export interface Deadline {
+  id: string;
+  tenant_id: string;
+  case_id: string;
+  title: string;
+  description?: string;
+  due_date: string;
+  original_due_date?: string;
+  warning_date?: string;
+  source: string;
+  rule_id?: string;
+  status: string;
+  completed_at?: string;
+  notes?: string;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface Appointment {
+  id: string;
+  tenant_id: string;
+  case_id?: string;
+  title: string;
+  description?: string;
+  start_at: string;
+  end_at?: string;
+  location?: string;
+  appointment_type?: string;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface CaseEvent {
+  id: string;
+  tenant_id: string;
+  case_id: string;
+  event_type?: string;
+  title: string;
+  description?: string;
+  event_date?: string;
+  created_by?: string;
+  metadata: Record<string, unknown>;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface Document {
+  id: string;
+  tenant_id: string;
+  case_id: string;
+  title: string;
+  doc_type?: string;
+  file_path?: string;
+  file_size?: number;
+  mime_type?: string;
+  ai_extracted?: Record<string, unknown>;
+  uploaded_by?: string;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface ApiError {
+  error: string;
+  status: number;
+}
+
+export interface PaginatedResponse<T> {
+  data: T[];
+  total: number;
+  page: number;
+  per_page: number;
+}

frontend/src/middleware.ts

@@ -0,0 +1,60 @@
+import { createServerClient } from "@supabase/ssr";
+import { NextResponse, type NextRequest } from "next/server";
+
+export async function middleware(request: NextRequest) {
+  let supabaseResponse = NextResponse.next({ request });
+
+  const supabase = createServerClient(
+    process.env.NEXT_PUBLIC_SUPABASE_URL!,
+    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
+    {
+      cookies: {
+        getAll() {
+          return request.cookies.getAll();
+        },
+        setAll(cookiesToSet) {
+          cookiesToSet.forEach(({ name, value }) =>
+            request.cookies.set(name, value),
+          );
+          supabaseResponse = NextResponse.next({ request });
+          cookiesToSet.forEach(({ name, value, options }) =>
+            supabaseResponse.cookies.set(name, value, options),
+          );
+        },
+      },
+    },
+  );
+
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+
+  const { pathname } = request.nextUrl;
+
+  // Auth pages — redirect to app if already logged in
+  if (user && (pathname === "/login" || pathname === "/register")) {
+    const url = request.nextUrl.clone();
+    url.pathname = "/";
+    return NextResponse.redirect(url);
+  }
+
+  // Protected routes — redirect to login if not authenticated
+  if (
+    !user &&
+    !pathname.startsWith("/login") &&
+    !pathname.startsWith("/register") &&
+    !pathname.startsWith("/callback")
+  ) {
+    const url = request.nextUrl.clone();
+    url.pathname = "/login";
+    return NextResponse.redirect(url);
+  }
+
+  return supabaseResponse;
+}
+
+export const config = {
+  matcher: [
+    "/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)",
+  ],
+};