Conventions

---
description: Quick reference for n8n patterns. Full docs /AGENTS.md
---

# n8n Quick Reference

**📚 Full Documentation:**
- **General:** `/AGENTS.md` - Architecture, commands, workflows
- **Frontend:** `/packages/frontend/AGENTS.md` - CSS variables, timing

Use this skill when you need quick reminders on critical patterns.

## Critical Rules (Must Follow)

**TypeScript:**
- Never `any` → use `unknown`
- Prefer `satisfies` over `as` (except tests)
- Shared types in `@n8n/api-types`

**Error Handling:**
```typescript
import { UnexpectedError } from 'n8n-workflow';
throw new UnexpectedError('message', { extra: { context } });
// DON'T use deprecated ApplicationError
```

**Frontend:**
- Vue 3 Composition API (`<script setup lang="ts">`)
- CSS variables (never hardcode px) - see `/packages/frontend/AGENTS.md`
- All text via i18n (`$t('key')`)
- `data-testid` for E2E (single value, no spaces)

**Backend:**
- Controller → Service → Repository
- Dependency injection via `@n8n/di`
- Config via `@n8n/config`
- Zod schemas for validation

**Testing:**
- Vitest (unit), Playwright (E2E)
- Mock external dependencies
- Work from package directory: `pushd packages/cli && pnpm test`

**Database:**
- SQLite/PostgreSQL only (app DB)
- Exception: DB nodes (MySQL Node, etc.) can use DB-specific features

**Commands:**
```bash
pnpm build > build.log 2>&1  # Always redirect
pnpm typecheck               # Before commit
pnpm lint                    # Before commit
```

## Key Packages

| Package | Purpose |
|---------|---------|
| `packages/cli` | Backend API |
| `packages/frontend/editor-ui` | Vue 3 frontend |
| `packages/@n8n/api-types` | Shared types |
| `packages/@n8n/db` | TypeORM entities |
| `packages/workflow` | Core interfaces |

## Common Patterns

**Pinia Store:**
```typescript
import { STORES } from '@n8n/stores';
export const useMyStore = defineStore(STORES.MY_STORE, () => {
  const state = shallowRef([]);
  return { state };
});
```

**Vue Component:**
```vue
<script setup lang="ts">
type Props = { title: string };
const props = defineProps<Props>();
</script>
```

**Service:**
```typescript
import { Service } from '@n8n/di';
import { Config } from '@n8n/config';

@Service()
export class MyService {
  constructor(private readonly config: Config) {}
}
```

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📖 **Need more details?** Read `/AGENTS.md` and `/packages/frontend/AGENTS.md`