Query ClickHouse databases using the chcli CLI tool. Use when the user wants to run SQL queries against ClickHouse, explore database schemas, inspect tables, or extract data from ClickHouse.

Code architecture patterns. Use when organizing code, refactoring classes, designing service structure, or extracting/moving code to new files. Enforces function ordering, service functions over classes, dependency injection.

Environment variable management patterns. CRITICAL use when adding new environment variables (secrets, API keys, config), debugging "X not defined" or missing env var errors, tests passing locally but failing in CI, Turborepo not passing env vars to tasks, or troubleshooting deployment configuration errors.

CRITICAL - Fetch real-time, official library documentation instead of relying on potentially outdated training data. Use WHENEVER working with ANY external library, framework, or package (React, Vue, Express, etc.) to get the latest APIs, usage patterns, and best practices directly from authoritative sources. Essential for accurate implementation - your training data may be months or years old, but this fetches current docs.

Use when creating a pull request. Runs verification, reviews changes, and creates the PR with correct metadata. Invoke BEFORE pushing code.

CRITICAL - Invoke BEFORE writing ANY test code. Use when creating new tests, adding test cases, modifying existing tests, writing `it()` or `describe()` blocks, or touching any `*.test.ts` or `*.spec.ts` file. Enforces no try-catch in positive tests, no early returns, no test skipping.

TypeScript coding standards. Use when writing TypeScript, reviewing code, or refactoring. Enforces named exports, no dynamic imports, discriminated unions, proper type safety.