Context7 MCP

Instructions

Implementation Reference

• src/index.ts:89-129 (handler)

  The main handler function implementing the 'resolve-library-id' tool. It searches for libraries using searchLibraries, handles errors, formats results, and returns structured content.
  async ({ libraryName }) => { const searchResponse: SearchResponse = await searchLibraries(libraryName); if (!searchResponse.results || searchResponse.results.length === 0) { return { content: [ { type: "text", text: searchResponse.error ? searchResponse.error : "Failed to retrieve library documentation data from Context7", }, ], }; } const resultsText = formatSearchResults(searchResponse); return { content: [ { type: "text", text: `Available Libraries (top matches): Each result includes: - Library ID: Context7-compatible identifier (format: /org/project) - Name: Library or package name - Description: Short summary - Code Snippets: Number of available code examples - Trust Score: Authority indicator - Versions: List of versions if available. Use one of those versions if and only if the user explicitly provides a version in their query. For best results, select libraries based on name match, trust score, snippet coverage, and relevance to your use case. ---------- ${resultsText}`, }, ], }; }
• src/index.ts:84-88 (schema)

  Zod input schema defining the 'libraryName' parameter for the tool.
  { libraryName: z .string() .describe("Library name to search for and retrieve a Context7-compatible library ID."), },
• src/index.ts:64-130 (registration)

  Registration of the 'resolve-library-id' tool using McpServer.tool() including description, schema, and handler.
  "resolve-library-id", `Resolves a package/product name to a Context7-compatible library ID and returns a list of matching libraries. You MUST call this function before 'get-library-docs' to obtain a valid Context7-compatible library ID UNLESS the user explicitly provides a library ID in the format '/org/project' or '/org/project/version' in their query. Selection Process: 1. Analyze the query to understand what library/package the user is looking for 2. Return the most relevant match based on: - Name similarity to the query (exact matches prioritized) - Description relevance to the query's intent - Documentation coverage (prioritize libraries with higher Code Snippet counts) - Trust score (consider libraries with scores of 7-10 more authoritative) Response Format: - Return the selected library ID in a clearly marked section - Provide a brief explanation for why this library was chosen - If multiple good matches exist, acknowledge this but proceed with the most relevant one - If no good matches exist, clearly state this and suggest query refinements For ambiguous queries, request clarification before proceeding with a best-guess match.`, { libraryName: z .string() .describe("Library name to search for and retrieve a Context7-compatible library ID."), }, async ({ libraryName }) => { const searchResponse: SearchResponse = await searchLibraries(libraryName); if (!searchResponse.results || searchResponse.results.length === 0) { return { content: [ { type: "text", text: searchResponse.error ? searchResponse.error : "Failed to retrieve library documentation data from Context7", }, ], }; } const resultsText = formatSearchResults(searchResponse); return { content: [ { type: "text", text: `Available Libraries (top matches): Each result includes: - Library ID: Context7-compatible identifier (format: /org/project) - Name: Library or package name - Description: Short summary - Code Snippets: Number of available code examples - Trust Score: Authority indicator - Versions: List of versions if available. Use one of those versions if and only if the user explicitly provides a version in their query. For best results, select libraries based on name match, trust score, snippet coverage, and relevance to your use case. ---------- ${resultsText}`, }, ], }; } );
• src/lib/api.ts:11-36 (helper)

  Helper function searchLibraries that performs the API call to Context7 search endpoint, called by the tool handler.
  export async function searchLibraries(query: string): Promise<SearchResponse> { try { const url = new URL(`${CONTEXT7_API_BASE_URL}/v1/search`); url.searchParams.set("query", query); const response = await fetch(url); if (!response.ok) { const errorCode = response.status; if (errorCode === 429) { console.error(`Rate limited due to too many requests. Please try again later.`); return { results: [], error: `Rate limited due to too many requests. Please try again later.`, } as SearchResponse; } console.error(`Failed to search libraries. Please try again later. Error code: ${errorCode}`); return { results: [], error: `Failed to search libraries. Please try again later. Error code: ${errorCode}`, } as SearchResponse; } return await response.json(); } catch (error) { console.error("Error searching libraries:", error); return { results: [], error: `Error searching libraries: ${error}` } as SearchResponse; } }
• src/lib/utils.ts:44-51 (helper)

  Helper function formatSearchResults that formats the search results into readable text, used in the tool handler.
  export function formatSearchResults(searchResponse: SearchResponse): string { if (!searchResponse.results || searchResponse.results.length === 0) { return "No documentation libraries found matching your query."; } const formattedResults = searchResponse.results.map(formatSearchResult); return formattedResults.join("\n----------\n"); }