| name | live-docs |
| description | Use before writing/reviewing code that calls into any external library, API, or framework. Training data goes stale — fetch version-specific docs before writing. Identify the exact installed version from package.json/Cargo.toml first, then fetch matching docs.
|
Live Documentation Lookup
Training data goes stale. APIs change. Before writing code that depends on any external library, fetch the current docs.
Step 1 — Identify installed versions
Read(file_path: "/absolute/path/to/package.json")
For lock file details:
grep -A 2 '"<package>"' package-lock.json
For Rust crates:
grep -A 2 'name = "<crate>"' Cargo.lock
The version number matters. The same library at v1 and v2 can have completely different APIs.
Step 2 — Find the right docs
| Ecosystem | Doc location |
|---|
| npm (JS/TS) | npmjs.com/package/<n> linked docs |
| crates.io (Rust) | docs.rs/<n>/<version>/ |
For version-pinned docs:
docs.rs/<crate>/<version>/ — Rust, always version-pinned- GitHub releases:
github.com/<org>/<repo>/releases
- GitHub tags:
github.com/<org>/<repo>/tree/v<version>
Step 3 — Fetch before you write
Search specifically — include library name, version, and the exact API:
expo-file-system 55 Directory API
react-native-reanimated 4.x useAnimatedStyle
@tanstack/react-query 5 useMutation options
What to look for
- Function/method signatures — params, types, order, required vs optional
- Return types — especially async or error-returning APIs
- Breaking changes since the version you know
- Required setup — imports, initialization, config
- Deprecations — old way may compile but new way is correct
Step 4 — Apply what you found
- Use exact signatures from docs — don't guess missing params
- Match the installed version — don't write against a different version's API
- Check required setup steps
- Flag outdated versions if significantly behind
High-churn categories — always fetch
- AI/LLM SDKs (OpenAI, Anthropic)
- Mobile platform APIs (Expo, iOS, Android)
- React Native libraries (Reanimated, Gesture Handler, Flash List)
- Any library after a major version bump
When docs are unavailable
- GitHub README, releases, source code
- Read type signatures from
node_modules or the repo directly
- If unverifiable — tell the user, leave a TODO comment
