buster/CLAUDE.md

# CLAUDE.md

This file provides guidance to Claude Code when working with code in this monorepo.

**Note**: Many packages and apps have their own CLAUDE.md files with specific implementation details and patterns. Always check for a local CLAUDE.md when working in a specific directory.

## Monorepo Structure

This is a pnpm-based monorepo using Turborepo with the following structure:

**Package Naming Convention:**
- All packages are scoped under `@buster/{package-name}` (e.g., `@buster/ai`, `@buster/database`)
- All apps are scoped under `@buster-app/{app-name}` (e.g., `@buster-app/web`, `@buster-app/server`)

### Apps (`@buster-app/*`)
- `apps/web` - Next.js frontend application
- `apps/server` - Node.js/Hono backend server  
- `apps/trigger` - Background job processing with Trigger.dev v3
- `apps/electric-server` - Electric SQL sync server
- `apps/api` - Rust backend API (legacy)
- `apps/cli` - Command-line tools (Rust)

### Packages (`@buster/*`)
- `packages/ai` - AI agents, tools, and workflows using Mastra framework
- `packages/database` - Database schema, migrations, and utilities (Drizzle ORM)
- `packages/data-source` - Data source adapters (PostgreSQL, MySQL, BigQuery, Snowflake, etc.)
- `packages/access-controls` - Permission and access control logic
- `packages/stored-values` - Stored values management
- `packages/rerank` - Document reranking functionality
- `packages/server-shared` - Shared server types and utilities
- `packages/test-utils` - Shared testing utilities
- `packages/vitest-config` - Shared Vitest configuration
- `packages/typescript-config` - Shared TypeScript configuration
- `packages/web-tools` - Web scraping and research tools
- `packages/slack` - Standalone Slack integration (OAuth, messaging, channels)
- `packages/supabase` - Supabase setup and configuration
- `packages/sandbox` - Sandboxed code execution using Daytona SDK

## Development Workflow

When writing code, follow this workflow to ensure code quality:

### 1. Write Modular, Testable Functions
- Create small, focused functions with single responsibilities
- Design functions to be easily testable with clear inputs/outputs
- Use dependency injection for external dependencies
- **IMPORTANT: Write functional, composable code - avoid classes**
- All features should be composed of testable functions
- Follow existing patterns in the codebase

### 2. Build Features by Composing Functions
- Combine modular functions to create complete features
- Keep business logic separate from infrastructure concerns
- Use proper error handling at each level

### 3. Commit Code Frequently
- **Commit frequently** - Make local commits often as you complete logical chunks of work
- **Write descriptive commit messages** - Focus on what and why, not just what changed
- **Keep commits atomic** - Each commit should represent one logical change
- **Use conventional commit format** when possible:
  - `feat:` for new features
  - `fix:` for bug fixes
  - `refactor:` for code changes that neither fix bugs nor add features
  - `docs:` for documentation changes
  - `test:` for test additions or modifications
  - `chore:` for maintenance tasks
- **Do NOT include "Generated by Claude Code"** or similar attribution in commit messages
- Example commit messages:
  - `feat: add OAuth authentication to user service`
  - `fix: resolve race condition in database connection pool`
  - `refactor: extract validation logic into separate functions`

## Environment Variables

This project uses a centralized environment variable system:

1. **All environment variables are defined at the root level** in a single `.env` file
2. **Turbo passes these variables** to all packages via the `globalEnv` configuration in `turbo.json`
3. **Individual packages validate** their required environment variables using the shared `@buster/env-utils` package

### Setting Up Environment Variables

1. Copy `.env.example` to `.env` at the project root:
   ```bash
   cp .env.example .env
   ```

2. Fill in the required values in `.env`

3. All packages will automatically have access to these variables through Turbo

### Adding New Environment Variables

When adding new environment variables:

1. Add the variable to `.env.example` with a descriptive comment
2. Add the variable name to the `globalEnv` array in `turbo.json`
3. Update the package's `validate-env.js` script to include the new variable
4. Update the package's `env.d.ts` file with the TypeScript type definition

### Migrating Packages to Centralized Env

To migrate an existing package to use the centralized environment system:

1. Remove any local `.env` files from the package
2. Add `@buster/env-utils` as a dependency:
   ```json
   "@buster/env-utils": "workspace:*"
   ```
3. Update the package's `scripts/validate-env.js` to use the shared utilities:
   ```javascript
   import { loadRootEnv, validateEnv } from '@buster/env-utils';
   
   loadRootEnv();
   
   const requiredEnv = {
     DATABASE_URL: process.env.DATABASE_URL,
     // ... other required variables
   };
   
   const { hasErrors } = validateEnv(requiredEnv);
   if (hasErrors) process.exit(1);
   ```

### 3. Ensure Type Safety
```bash
# Build entire monorepo to check types
turbo run build:dry-run

# Build specific package/app
turbo run build:dry-run --filter=@buster/ai
turbo run build:dry-run --filter=@buster-app/web

# Or
turbo run build
```

### 4. Run Linting & Formatting
```bash
# Run linting (checks and auto-fixes issues)
turbo run lint
turbo run lint --filter=@buster/ai

# Filter to specific package
turbo run lint --filter=@buster-app/web
```

### 5. Run Tests with Vitest

**Important**: Always run unit tests before completing any task to ensure code changes don't break existing functionality.

```bash
# Run unit tests (always run these when working locally)
turbo run test:unit

# Run unit tests for specific package
turbo run test:unit --filter=@buster/ai

# Run integration tests ONLY for specific features/packages you're working on
turbo run test:integration --filter=@buster/database

# Watch mode for development
turbo run test:watch
```

### 6. Pre-Completion Checklist
**IMPORTANT: Before finishing any task or creating PRs, always run:**
```bash
# 1. Run unit tests for the entire monorepo
turbo run test:unit

# 2. Build dry-run to ensure everything compiles (faster than full build)
turbo run build:dry-run

# 3. Run linting for the entire monorepo
turbo run lint

# Or run all checks simultaneously:
turbo run build:dry-run lint test:unit
```

**Key Testing Guidelines:**
- **Always run unit tests, build:dry-run, and lint** when working locally before considering a task complete
- **Unit tests** should be run for the entire monorepo to catch any breaking changes
- **Build:dry-run** must pass for the entire monorepo to ensure type safety
- **Integration tests** should only be run for specific packages/features you're working on (NOT the entire monorepo)
- **Fix all failing tests, build errors, and lint errors** before completing any task
- **Heavily bias toward unit tests** - they are faster and cheaper to run
- **Mock everything you can** in unit tests for isolation and speed

**Filtering Commands to Specific Packages:**
All turbo commands support filtering to specific packages using the `--filter` flag:
- `turbo run test:unit --filter=@buster/ai`
- `turbo run build:dry-run --filter=@buster-app/web`
- `turbo run lint --filter=packages/database`

## Code Quality Standards

### TypeScript Configuration
- **Strict mode enabled** - All strict checks are on
- **No implicit any** - Always use specific types
- **Strict null checks** - Handle null/undefined explicitly
- **No implicit returns** - All code paths must return
- **Consistent file casing** - Enforced by TypeScript

### Type Safety and Zod Best Practices
- We care deeply about type safety and we use Zod schemas and then export them as types
- We prefer using type abstractions over `.parse()` method calls
- Always export Zod schemas as TypeScript types to leverage static type checking
- Avoid runtime type checking when compile-time type checks are sufficient

### Biome Rules (Key Enforcements)
- **`useImportType: "warn"`** - Use type-only imports when possible
- **`noExplicitAny: "error"`** - Never use `any` type
- **`noUnusedVariables: "error"`** - Remove unused code
- **`noNonNullAssertion: "error"`** - No `!` assertions
- **`noConsoleLog: "warn"`** - Avoid console.log in production
- **`useNodejsImportProtocol: "error"`** - Use `node:` prefix for Node.js imports

### Logging Guidelines
- **Never use `console.log`**
- **Use appropriate console methods**:
  - `console.info` for general information
  - `console.warn` for warning messages
  - `console.error` for error messages

## Error Handling and Logging Philosophy
- We care deeply about error handling and logging
- Key principles for error management:
  - Catch errors effectively and thoughtfully
  - Consider the state errors put the system into
  - Implement comprehensive unit tests for error scenarios
  - Log errors strategically for effective debugging
  - Avoid over-logging while ensuring sufficient context for troubleshooting

## Hono API Development Guidelines

### API Structure and Organization
- **Version-based organization** - APIs are organized under `/api/v2/` directory
- **Feature-based folders** - Each feature gets its own folder (e.g., `chats/`, `security/`)
- **Separate handler files** - Each endpoint handler must be in its own file
- **Functional handlers** - All handlers should be pure functions that accept request data and return response data

### Request/Response Type Safety
- **Use shared types** - All request and response types must be defined in `@buster/server-shared`
- **Zod schemas** - Define schemas in server-shared and export both the schema and inferred types
- **zValidator middleware** - Always use `zValidator` from `@hono/zod-validator` for request validation
- **Type imports** - Import types from server-shared packages for consistency

### Handler Pattern
```typescript
// Handler file (e.g., get-workspace-settings.ts)
import type { GetWorkspaceSettingsResponse } from '@buster/server-shared/security';
import type { User } from '@buster/database';

export async function getWorkspaceSettingsHandler(
  user: User
): Promise<GetWorkspaceSettingsResponse> {
  // Implementation
}

// Route definition (index.ts)
.get('/workspace-settings', async (c) => {
  const user = c.get('busterUser');
  const response = await getWorkspaceSettingsHandler(user);
  return c.json(response);
})
```

### Authentication and User Context
- **Use requireAuth middleware** - Apply to all protected routes
- **Extract user context** - Use `c.get('busterUser')` to get the authenticated user
- **Type as User** - Import `User` type from `@buster/database` for handler parameters

## Database Operations

### Query Organization
- **All database queries must be created as helper functions** in `@packages/database/src/queries/`
- **Organize by table** - Each table should have its own subdirectory (e.g., `assets/`, `chats/`, `users/`)
- **Type all queries** - Every query function must have properly typed parameters and return types
- **Export from index** - Each subdirectory should have an `index.ts` that exports all queries for that table
- **Reusable and composable** - Write queries as small, focused functions that can be composed together

### Soft Delete and Upsert Practices
- In our database, we never hard delete, we always use soft deletes with the `deleted_at` field
- For update operations, we should almost always perform an upsert unless otherwise specified

## Test Running Guidelines
- When running tests, use the following Turbo commands:
  - `turbo run test:unit` for unit tests
  - `turbo run test:integration` for integration tests
  - `turbo run test` for running all tests
  - Add `--filter=<package-name>` to run tests for specific packages

### Database Access for Integration Testing
- **Direct database queries** - You can run queries against the local database using `psql` with the following connection:
  ```bash
  DATABASE_URL="postgresql://postgres:postgres@127.0.0.1:54322/postgres"
  ```
- **Usage example**:
  ```bash
  psql "postgresql://postgres:postgres@127.0.0.1:54322/postgres" -c "SELECT * FROM users LIMIT 5;"
  ```
- **Purpose** - This is primarily for writing and iterating on integration tests to verify database state and test query behavior

## Pre-Completion Workflow
- Always run `turbo run test:unit`, `turbo run lint`, and `turbo run build:dry-run` before making any pull request or finishing a feature, bugfix, etc. to ensure things make it through CI/CD
- You can run all these checks simultaneously with `turbo run build:dry-run lint test:unit`