feat: setup AGENTS.md file

AGENTS.md

@@ -0,0 +1,315 @@
+# AGENTS.md
+
+## Project Overview
+
+Kan is an open-source project management tool (Trello alternative) built with:
+
+- **Frontend**: Next.js, React, TypeScript, Tailwind CSS
+- **Backend**: tRPC, Node.js
+- **Database**: PostgreSQL with Drizzle ORM
+- **Monorepo**: pnpm workspaces with Turbo
+- **Auth**: Better Auth
+- **Internationalization**: Lingui
+
+## Setup Commands
+
+- Install deps: `pnpm install`
+- Start dev server: `pnpm dev`
+- Create migrations: `cd packages/db && pnpm drizzle-kit generate --name "AddFieldToTable"`
+- Run database migrations: `pnpm db:migrate`
+- Run linter: `pnpm lint`
+- Run type check: `pnpm typecheck`
+- Format code: `pnpm format:fix`
+- Extract i18n strings: `pnpm lingui:extract`
+
+## Project Structure
+
+- `apps/web/` - Next.js web application
+- `packages/api/` - tRPC API routers
+- `packages/db/` - Database schema, migrations, and repositories
+- `packages/auth/` - Authentication package
+- `packages/shared/` - Shared utilities
+- `packages/email/` - Email templates and sending
+- `packages/stripe/` - Stripe integration
+- `tooling/` - Shared tooling configs (ESLint, Prettier, TypeScript)
+
+## Code Style
+
+### TypeScript
+
+- Use TypeScript strictly - avoid `any` types
+- Prefer explicit types over inference when it improves clarity
+- Use `as const` for literal types when appropriate
+- Follow existing patterns for type definitions
+
+### Naming Conventions
+
+- **Files**: kebab-case for files (e.g., `card-repo.ts`)
+- **Components**: PascalCase for React components
+- **Functions**: camelCase for functions
+- **Constants**: UPPER_SNAKE_CASE for constants
+- **Types/Interfaces**: PascalCase
+
+### Database Layer (`packages/db/`)
+
+- **Schema**: Define schemas in `src/schema/` using Drizzle ORM
+- **Migrations**: Create migrations with `cd packages/db && pnpm drizzle-kit generate --name "MigrationName"`, then run with `pnpm db:migrate`
+- **Repositories**: Put database queries in `src/repository/` files
+- **Soft Deletes**: Use `deletedAt` timestamp for soft deletion (not hard deletes)
+- **Index Management**: Cards have `index` fields that must be maintained sequentially per list
+- **Activity Logging**: Use `card_activity` table to track all card changes
+
+### API Layer (`packages/api/`)
+
+- **Routers**: Create tRPC routers in `src/routers/`
+- **Procedures**: Use `protectedProcedure` for authenticated endpoints, `publicProcedure` for public
+- **Validation**: Use Zod schemas for input validation
+- **Error Handling**: Use `TRPCError` with appropriate error codes
+- **OpenAPI**: Add OpenAPI metadata for all endpoints
+- **Authorization**: Always check workspace membership with `assertUserInWorkspace`
+
+### Frontend (`apps/web/`)
+
+- **Components**: React components in `src/components/`
+- **Views**: Page-level components in `src/views/`
+- **Hooks**: Custom hooks in `src/hooks/`
+- **i18n**: Use `t` template literal for translations (Lingui)
+- **Styling**: Use Tailwind CSS classes
+- **State Management**: Use tRPC React Query hooks for server state
+- **Modals**: Use `useModal` hook for modal management
+- **Popups**: Use `usePopup` hook for toast notifications
+
+## Key Concepts
+
+### Cards
+
+- Cards are the main entity in Kan
+- Cards belong to Lists, which belong to Boards
+- Cards have: title, description, labels, members, checklists, comments, attachments, due dates
+- Cards use soft deletion (`deletedAt` field)
+- Cards have an `index` field that must be maintained sequentially per list
+- All card changes are tracked in `card_activity` table
+
+### Activity Tracking
+
+- Every significant card change creates an activity record
+- Activity types include: created, updated (various fields), etc.
+- Activities are displayed in card activity feeds
+
+### Workspaces & Boards
+
+- Users belong to Workspaces
+- Boards belong to Workspaces
+- Workspace members have different permission levels
+- Boards can be public or private
+
+### Soft Deletion Pattern
+
+- Entities use `deletedAt` timestamp for soft deletion
+- Queries filter with `isNull(table.deletedAt)` to exclude deleted items
+
+## File Locations Reference
+
+### Database
+
+- Schema: `packages/db/src/schema/*.ts`
+- Repositories: `packages/db/src/repository/*.repo.ts`
+- Migrations: `packages/db/migrations/`
+
+### API
+
+- Routers: `packages/api/src/routers/*.ts`
+- Utils: `packages/api/src/utils/`
+- Types: `packages/api/src/types/`
+
+### Frontend
+
+- Components: `apps/web/src/components/`
+- Views: `apps/web/src/views/`
+- Pages: `apps/web/src/pages/`
+- Hooks: `apps/web/src/hooks/`
+- Utils: `apps/web/src/utils/`
+- Locales: `apps/web/src/locales/`
+
+## Database Patterns
+
+- **Soft Deletes**: Always filter with `isNull(table.deletedAt)` in queries
+- **Public IDs**: Use 12-character public IDs (`publicId`) for all user-facing entities
+- **Internal IDs**: Never expose internal database IDs (e.g., `id`, `cardId`, `listId`) in API responses or URLs - always use `publicId` externally
+- **Transactions**: Use database transactions for multi-step operations
+- **Index Management**: When deleting/moving cards, maintain sequential indices
+- **Activity Tracking**: Create activity records for all significant changes
+
+## API Patterns
+
+- **Input Validation**: Always validate inputs with Zod
+- **Error Messages**: Provide clear, user-friendly error messages
+- **Optimistic Updates**: Use tRPC's `onMutate` for optimistic UI updates
+- **Cache Invalidation**: Properly invalidate queries after mutations
+- **ID Exposure**: Never expose internal database IDs (`id`, `cardId`, `listId`, etc.) in API responses, URLs, or frontend code - always use `publicId` for external communication
+
+## Important Patterns
+
+### Card Index Management
+
+When cards are created, moved, or deleted, their indices must be maintained:
+
+- New cards: Append to end (max index + 1) or insert at position
+- Moving cards: Adjust indices of affected cards
+- Deleting cards: Decrement indices of cards after deleted one
+- Always use transactions for index updates
+
+### Activity Logging
+
+Create activity records for:
+
+- Card creation
+- Card updates (title, description, list, etc.)
+- Label/member additions/removals
+- Comments
+- Checklists and items
+- Attachments
+- Due dates
+
+### Authorization
+
+Always check:
+
+1. User is authenticated
+2. User has access to workspace
+3. User has permission for the operation
+
+Use `assertUserInWorkspace` helper for workspace checks.
+
+### Error Handling
+
+- Use TRPCError with appropriate codes (UNAUTHORIZED, NOT_FOUND, etc.)
+- Provide user-friendly error messages
+- Log errors appropriately
+- Show popup notifications for user-facing errors
+
+## Common Patterns
+
+### Creating a Card
+
+1. Create card in repository with proper index management
+2. Create `card.created` activity
+3. Handle label/member relationships if provided
+4. Return the created card
+
+### Updating a Card
+
+1. Validate user has workspace access
+2. Update card fields
+3. Create appropriate activity records
+4. Invalidate relevant queries
+
+### Querying Cards
+
+- Always filter by `isNull(cards.deletedAt)` in queries
+- Include related data (labels, members, checklists) via Drizzle relations
+- Order by `index` for proper card ordering
+
+## Adding a New Feature
+
+1. **Database**: Update schema in `packages/db/src/schema/`
+2. **Migration**: Create migration with `cd packages/db && pnpm drizzle-kit generate --name "MigrationName"`, then run with `pnpm db:migrate`
+3. **Repository**: Add repository functions in `packages/db/src/repository/`
+4. **API**: Add tRPC router procedures in `packages/api/src/routers/`
+5. **Frontend**: Add UI components in `apps/web/src/`
+6. **i18n**: Add translations for new strings
+
+## Database Changes
+
+- Always create migrations (never modify existing migrations)
+- Create migrations with: `cd packages/db && pnpm drizzle-kit generate --name "MigrationName"`
+- Run migrations with: `pnpm db:migrate`
+- Update schema files in `packages/db/src/schema/`
+- Test migrations on development database first
+- Update TypeScript types after schema changes
+- Consider index management for card operations
+
+## API Endpoints
+
+- Use tRPC procedures (not REST)
+- Add OpenAPI metadata for documentation
+- Validate inputs with Zod
+- Check workspace permissions
+- Create activity records for significant changes
+
+## Frontend Components
+
+- Use Tailwind for styling
+- Follow existing component patterns
+- Use tRPC hooks for data fetching
+- Implement optimistic updates where appropriate
+- Add proper loading and error states
+
+## Testing Instructions
+
+- Test database operations in transactions that rollback
+- Test authorization checks
+- Test index management when moving/deleting cards
+- Test activity logging
+- Test UI interactions
+- Run `pnpm lint` and `pnpm typecheck` before committing
+
+## Performance Considerations
+
+- Use database indexes appropriately
+- Batch operations when possible
+- Avoid N+1 queries
+- Use transactions for related operations
+- Implement optimistic updates in UI
+
+## Security
+
+- Always check workspace membership before operations
+- Validate all inputs
+- Never expose internal database IDs (`id`, `cardId`, `listId`, etc.) in API responses, URLs, or frontend code - always use `publicId` externally
+- Sanitize user input
+
+## Internationalization
+
+- All user-facing strings must use `t` template literal
+- Add translations to locale files in `apps/web/src/locales/`
+- Run `pnpm lingui:extract` to update translation files
+- Update locale files for all languages
+
+## Dependencies
+
+- Use workspace dependencies (`workspace:*`) for internal packages
+- Keep dependencies up to date
+- Use catalog for shared dependency versions
+
+## When Implementing Features
+
+### Adding New Card Fields
+
+1. Update schema in `packages/db/src/schema/cards.ts`
+2. Create migration
+3. Update repository functions
+4. Add API endpoints
+5. Update frontend components
+6. Add activity tracking if needed
+
+### Adding New Activity Types
+
+1. Add to `activityTypes` array in schema
+2. Create migration to update enum
+3. Use in activity creation code
+4. Update activity display components if needed
+
+## Git & Commits
+
+- Use conventional commits: `feat:`, `fix:`, `refactor:`, `docs:`, etc.
+- Keep commits focused on single changes
+- Reference issue numbers when applicable
+
+## PR Instructions
+
+- Title format: `feat: description` or `fix: description`
+- Always run `pnpm lint` and `pnpm typecheck` before committing
+- Provide clear description of changes
+- Include screenshots for UI changes
+- Keep PRs focused on a single feature/fix