# Claw Routing Service - Development Rules

## Service Overview

Routing microservice for the Claw platform. Manages AI routing decisions and policies. Runs on port 4004 with its own PostgreSQL database (claw_routing).

## Tech Stack

- **Runtime**: NestJS 10 with TypeScript (strict mode enabled)
- **Database**: PostgreSQL with Prisma ORM (claw_routing database, port 5444)
- **Cache**: Redis (ioredis)
- **Messaging**: RabbitMQ (amqplib)
- **Validation**: Zod (NOT class-validator, NOT class-transformer)
- **Auth**: JWT (jsonwebtoken) for token verification
- **Logging**: nestjs-pino / pino structured logging

## Absolute Rules

1. **NEVER use `any`** -- use `unknown`, generics, or proper types.
2. **NEVER disable ESLint rules** -- no `eslint-disable`, `@ts-ignore`, `@ts-expect-error`.
3. **NEVER use `console.log`** -- use the NestJS `Logger` service.
4. **NEVER use `!` non-null assertion** -- handle nullability explicitly.
5. **NEVER use `process.env` directly** -- use `AppConfig` from `src/app/config/app.config.ts`.
6. **NEVER put business logic in controllers** -- controllers call exactly ONE service method.
7. **NEVER put Prisma calls outside repositories** -- repositories are the sole data-access layer.
8. **EVERY function must have an explicit return type**.
9. **Service methods max 30 lines**.
10. **Controllers are 3-line methods**: extract params, call ONE service, return result.
11. **All errors use BusinessException with a code**.
12. **No default exports** -- use named exports exclusively.

## No Inline Declarations Rule

**NEVER** define `type`, `interface`, `enum`, or module-level `const` inline in service, controller, repository, manager, adapter, utility, guard, filter, interceptor, pipe, or module files. Extract to dedicated files:

- Types/interfaces → `src/modules/<domain>/types/<name>.types.ts`
- Enums → `src/common/enums/<name>.enum.ts`
- Constants → `src/modules/<domain>/constants/<name>.constants.ts`
  Only exception: `private readonly logger = new Logger(...)` inside NestJS classes.

## Library Wrapping Rule

Every third-party library MUST be wrapped in a utility file under `src/common/utilities/`. Services and controllers NEVER import third-party packages directly — they import the wrapper. Example: `src/common/utilities/jwt.utility.ts` wraps `jsonwebtoken`, and services import `{ signToken, verifyToken }` from the wrapper.

## Architecture

```
Controller -> Service -> Repository
```

## Owned Tables

- RoutingDecision
- RoutingPolicy

## Commands

```bash
npm run dev          # Start with hot reload
npm run build        # Production build
npm run typecheck    # TypeScript type check
npm run validate     # typecheck + lint:strict + format:check
npm run test         # Run unit tests
npm run migrate:dev  # Create and run migration
npm run prisma:generate  # Regenerate Prisma client
```

## Docker Container Rebuild Procedure

When rebuilding this service (especially after shared package changes):

```bash
./scripts/claw.sh stop routing-service
./scripts/claw.sh rm -f routing-service
docker rmi claw-routing-service
./scripts/claw.sh up -d --build routing-service
```

**NEVER skip steps.** See root CLAUDE.md for full explanation.

## Workflow Phase Requirements

All work on this service MUST follow the phases defined in the root `CLAUDE.md`:

- **Phase 0** (Planning Gate): Document impacted areas, risks, acceptance criteria before coding
- **Phase 0g** (Business Framing): Define user problem, success metrics, UAT seed for user-facing changes
- **Phase 1-3** (Implementation): Follow backend architecture rules above
- **Phase 4** (SSE rules if applicable): Apply SSE-specific patterns from root CLAUDE.md
- **Phase 5** (Error handling): All async errors stored + SSE emitted
- **Phase 8** (Validation): typecheck + lint + test + build before any commit
- **Phase 9** (API testing): Verify all new endpoints with curl/Postman before claiming done
- **Phase 12** (QE Gates): All phases from docs/16-quality-engineering/ must pass

## Pre-Implementation Checklist (this service)

Before writing code for this service:

- [ ] Read root CLAUDE.md
- [ ] Read this service CLAUDE.md
- [ ] Read existing service code for the area being changed
- [ ] Read current Prisma schema (if DB changes)
- [ ] Identify all RabbitMQ events published/consumed by this service
- [ ] Check if shared packages need updating

## Post-Implementation Checklist (this service)

After implementing any change to this service:

- [ ] `npm run typecheck` → 0 errors
- [ ] `npm run lint` → 0 errors
- [ ] `npm run test` → all pass
- [ ] `npm run build` → success
- [ ] All new Zod DTOs have: max() on strings, max() on arrays, required fields explicit
- [ ] All new service methods are ≤ 30 lines
- [ ] All new manager methods are ≤ 80 lines
- [ ] All new controllers are 3-line methods
- [ ] No try/catch in controllers
- [ ] No Prisma calls outside repositories
- [ ] All new events published using RabbitMQService
- [ ] All new messageKeys added to error catalog
- [ ] All background tasks use fire-and-forget with `void`
- [ ] All fire-and-forget error paths: `emitError` → `storeErrorMessage` in nested try-catch
- [ ] All poll-detected flows store metadata `{ error: true }` on failure

## Required Output Format

After completing any implementation task on this service, produce:

1. **Files changed** (list with purpose of each change)
2. **Tests added/updated** (list with what each test covers)
3. **API changes** (new endpoints, changed contracts)
4. **Infrastructure changes** (env vars, Docker, Nginx, CI)
5. **Known gaps or follow-up items**
6. **Evidence**: typecheck output, lint output, test output

## Llamacpp runtime health

`LlamacppHealthManager` (`src/modules/routing/managers/llamacpp-health.manager.ts`) polls `${LLAMACPP_SERVICE_URL}/api/v1/health` every 30 s and subscribes to `llamacpp.model.{loaded,unloaded,crashed}` events. Populates `runtimeHealthCache.set(LLAMACPP_RUNTIME, ...)` consumed by `RoutingManager.isRuntimeHealthy()` for fallback decisions. NEVER call the manager directly from a controller — use the cache via `RoutingService.evaluateRoute()`. Uses the existing `httpRequest` utility (do NOT add `undici` as a dep here).
