# AOS — Agency Operating System

## Project Overview
Self-hosted platform for German software agencies. Full lifecycle: Lead → Deal → Quote → Project → Invoice → License → Renewal. GoBD-compliant accounting (SKR04, EÜR, UStVA, DATEV). Client Portal. MCP Server for Claude Code.

## Tech Stack
- **Framework**: Next.js 16 (App Router, Turbopack)
- **Language**: TypeScript 5 (strict, 0 errors)
- **Database**: Prisma ORM (SQLite for dev)
- **UI**: shadcn/ui + Tailwind CSS 4 (monochrome design)
- **State**: Zustand + custom useFetch hook
- **AI**: z-ai-web-dev-sdk (server-side only, 3 AI flows)
- **i18n**: DE/EN/TR

## Commands
```bash
bun run dev              # Start dev server (port 3000)
bun run lint             # ESLint check
bun run db:push          # Push Prisma schema to DB
bun run db:generate      # Generate Prisma Client
bun run src/lib/seed.ts  # Seed database with realistic data
```

## Architecture
- **Modular monolith** — one deployable, strict module boundaries
- **Money**: integer cents, tax in basis points (1900 = 19%). No floats.
- **GoBD**: immutable after Festschreibung, corrections via Storno (new row)
- **Audit**: SHA-256 hash-chain on all business operations
- **Auth**: Bearer token (SHA-256 hashed at rest) with scoped permissions
- **No mocks** — real implementations only (TCP mail test, CAMT.053 parser, ELSTER XML)

## Key Directories
```
src/app/api/aos/        # Internal API (28+ endpoints)
src/app/api/v1/         # Public REST API (scoped tokens)
src/app/api/mcp/        # MCP Server (29 JSON-RPC tools)
src/app/api/health/     # Health check endpoint
src/components/aos/      # All UI components (23 views)
src/lib/                 # Shared logic (db, format, i18n, api-auth, webhook)
prisma/                  # Schema (30+ models)
.mcp.json               # Claude Code auto-detection
```

## MCP Server (29 Tools)

Claude Code auto-detects `.mcp.json` and connects with the seed admin token.

### Read Tools (16)
| Tool | Description |
|---|---|
| `search_companies` | Search CRM companies by name/city/website |
| `get_pipeline` | Sales pipeline deals by stage |
| `get_invoice` | Single invoice by number with E-Rechnung status |
| `list_leads` | Leads Finder queue with scores |
| `get_dashboard` | Agency KPIs (pipeline, MRR, projects) |
| `list_tickets` | Support tickets with SLA info |
| `get_buchhaltung` | SKR04 Konten, Journal, EÜR summary |
| `get_anlagen` | Anlagenverzeichnis with AfA depreciation |
| `get_kassenbuch` | Cash book entries, running balance |
| `get_belege` | Receipts with SHA-256 content hashes |
| `get_finanzamt` | VAT returns, Jahreserklärungen, Jahresarchive |
| `get_contracts` | Verträge (AVV, NDA, SLA, Werkvertrag) |
| `get_projects` | Projects with progress, budget, task counts |
| `get_timesheet` | Weekly timesheet grid with lock status |
| `get_notifications` | All alerts (overdue, expiring, SLA breaches) |
| `get_calendar` | Upcoming deadlines (30-day look-ahead) |

### Write Tools (13)
| Tool | Description |
|---|---|
| `approve_lead` | Approve a lead in the review queue |
| `create_ticket` | Create a support ticket |
| `create_deal` | Create a deal with value/stage/probability |
| `update_deal_stage` | Move deal through pipeline |
| `create_task` | Create a task with priority/assignee/estimate |
| `log_time` | Log billable time with rate |
| `create_invoice` | Create draft invoice with line items |
| `finalize_invoice` | Lock + send invoice (GoBD Festschreibung) |
| `run_recurring` | Run recurring invoice scheduler + license suspend |
| `create_buchung` | SKR04 Buchungssatz (Soll an Haben) |
| `create_beleg` | Register receipt (SHA-256, GoBD retention) |
| `create_pauschale` | Homeoffice/Kilometer/Verpflegung (auto-computed) |
| `create_kassenbuch_entry` | Cash book entry (§ 146 AO, immutable) |

### Usage Examples
```jsonc
// Search companies
{"name": "search_companies", "arguments": {"query": "Hamburg"}}

// Create a deal
{"name": "create_deal", "arguments": {"companyId": "abc123", "title": "Website Relaunch", "valueCents": 980000, "stage": "proposal"}}

// Log time
{"name": "log_time", "arguments": {"projectId": "xyz789", "description": "SSO integration", "minutes": 180, "rateCentsPerHour": 9500}}

// Create invoice + finalize
{"name": "create_invoice", "arguments": {"companyId": "abc123", "lines": [{"description": "Website Audit", "quantity": 1, "unitCents": 45000}]}}
{"name": "finalize_invoice", "arguments": {"invoiceId": "inv123", "zugferd": true}}

// Book a Buchungssatz (SKR04)
{"name": "create_buchung", "arguments": {"belegdatum": "2026-10-27", "sollKontoNummer": "4930", "habenKontoNummer": "1200", "betragCents": 89900, "buchungstext": "JetBrains Lizenz"}}

// Create a Kilometerpauschale
{"name": "create_pauschale", "arguments": {"type": "kilometer", "date": "2026-10-27", "km": 140, "vehicleType": "auto", "description": "Kundentermin Berlin"}}
```

## Compliance
- **GoBD**: Festschreibung (SHA-256), immutable Buchungssätze, 8/6 year retention
- **DSGVO**: Art. 15/17/20/30, consent log, data export with checksum
- **E-Rechnung**: ZUGFeRD/XRechnung (EN 16931)
- **SKR04**: Kontenrahmen, doppelte Buchführung, Saldenliste
- **EÜR**: Anlage EÜR with AVEÜR line numbers (§ 4 Abs. 3 EStG)
- **UStVA**: Kennzahlen 81/86/66/83/65/37, ELSTER XML
- **DATEV**: EXTF v5.0 Buchungsstapel export
- **AfA**: GWG (§ 6 Abs. 2), Sammelposten (§ 6 Abs. 2a), lineare AfA (§ 7)
- **Kassenbuch**: § 146 AO, § 22 UStG — immutable
- **Pauschalen**: EStG § 4 Abs. 5, § 9 Abs. 1 (Homeoffice, KM, Verpflegung)
- **Mahnwesen**: § 288 BGB Verzugszinsen, 3-stufig + license suspend

## Important Rules
- No mocks — real implementations only
- No `any` types — all interfaces explicitly typed
- All API routes: try/catch error handling
- All icon-only buttons: `aria-label` (WCAG 2.1 AA)
- Client Portal: no agency-internal details visible to clients
- German UI by default (i18n: DE/EN/TR)
- Money: cents (integer), tax: basis points. Never floats.

## Seed Token
Pre-built admin MCP token for Claude Code:
```
aos_admin_seed_token_for_claude_code_2026
```
Created by `bun run src/lib/seed.ts`. All read + write scopes.