documentation-lookup
Documentation Lookup (Context7)
When the user asks about libraries, frameworks, or APIs, fetch current documentation via the Context7 MCP (tools resolve-library-id and query-docs) instead of relying on training data.
Core Concepts
- Context7: MCP server that exposes live documentation; use it instead of training data for libraries and APIs.
- resolve-library-id: Returns Context7-compatible library IDs (e.g.
/vercel/next.js) from a library name and query. - query-docs: Fetches documentation and code snippets for a given library ID and question. Always call resolve-library-id first to get a valid library ID.
When to use
Activate when the user:
- Asks setup or configuration questions (e.g. "How do I configure Next.js middleware?")
- Requests code that depends on a library ("Write a Prisma query for...")
- Needs API or reference information ("What are the Supabase auth methods?")
- Mentions specific frameworks or libraries (React, Vue, Svelte, Express, Tailwind, Prisma, Supabase, etc.)
Use this skill whenever the request depends on accurate, up-to-date behavior of a library, framework, or API. Applies across harnesses that have the Context7 MCP configured (e.g. Claude Code, Cursor, Codex).
How it works
Step 1: Resolve the Library ID
Call the resolve-library-id MCP tool with:
- libraryName: The library or product name taken from the user's question (e.g.
Next.js,Prisma,Supabase). - query: The user's full question. This improves relevance ranking of results.
You must obtain a Context7-compatible library ID (format /org/project or /org/project/version) before querying docs. Do not call query-docs without a valid library ID from this step.
Step 2: Select the Best Match
From the resolution results, choose one result using:
- Name match: Prefer exact or closest match to what the user asked for.
- Benchmark score: Higher scores indicate better documentation quality (100 is highest).
- Source reputation: Prefer High or Medium reputation when available.
- Version: If the user specified a version (e.g. "React 19", "Next.js 15"), prefer a version-specific library ID if listed (e.g.
/org/project/v1.2.0).
Step 3: Fetch the Documentation
Call the query-docs MCP tool with:
- libraryId: The selected Context7 library ID from Step 2 (e.g.
/vercel/next.js). - query: The user's specific question or task. Be specific to get relevant snippets.
Limit: do not call query-docs (or resolve-library-id) more than 3 times per question. If the answer is unclear after 3 calls, state the uncertainty and use the best information you have rather than guessing.
Step 4: Use the Documentation
- Answer the user's question using the fetched, current information.
- Include relevant code examples from the docs when helpful.
- Cite the library or version when it matters (e.g. "In Next.js 15...").
Examples
Example: Next.js middleware
- Call resolve-library-id with
libraryName: "Next.js",query: "How do I set up Next.js middleware?". - From results, pick the best match (e.g.
/vercel/next.js) by name and benchmark score. - Call query-docs with
libraryId: "/vercel/next.js",query: "How do I set up Next.js middleware?". - Use the returned snippets and text to answer; include a minimal
middleware.tsexample from the docs if relevant.
Example: Prisma query
- Call resolve-library-id with
libraryName: "Prisma",query: "How do I query with relations?". - Select the official Prisma library ID (e.g.
/prisma/prisma). - Call query-docs with that
libraryIdand the query. - Return the Prisma Client pattern (e.g.
includeorselect) with a short code snippet from the docs.
Example: Supabase auth methods
- Call resolve-library-id with
libraryName: "Supabase",query: "What are the auth methods?". - Pick the Supabase docs library ID.
- Call query-docs; summarize the auth methods and show minimal examples from the fetched docs.
Best Practices
- Be specific: Use the user's full question as the query where possible for better relevance.
- Version awareness: When users mention versions, use version-specific library IDs from the resolve step when available.
- Prefer official sources: When multiple matches exist, prefer official or primary packages over community forks.
- No sensitive data: Redact API keys, passwords, tokens, and other secrets from any query sent to Context7. Treat the user's question as potentially containing secrets before passing it to resolve-library-id or query-docs.