Context7 MCP

Instructions

Implementation Reference

• packages/mcp/src/index.ts:142-190 (handler)

  The handler function that executes the 'resolve-library-id' tool logic: searches for libraries using searchLibraries, formats results with formatSearchResults, and returns formatted text response.
  async ({ libraryName }) => { const ctx = requestContext.getStore(); const searchResponse: SearchResponse = await searchLibraries( libraryName, ctx?.clientIp, ctx?.apiKey ); 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); const responseText = `Available Libraries: 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 - Source Reputation: Authority indicator (High, Medium, Low, or Unknown) - Benchmark Score: Quality indicator (100 is the highest score) - Versions: List of versions if available. Use one of those versions if the user provides a version in their query. The format of the version is /org/project/version. For best results, select libraries based on name match, source reputation, snippet coverage, benchmark score, and relevance to your use case. ---------- ${resultsText}`; return { content: [ { type: "text", text: responseText, }, ], }; }
• packages/mcp/src/index.ts:112-191 (registration)

  Registration of the 'resolve-library-id' tool with server.registerTool, including title, description, and input schema.
  server.registerTool( "resolve-library-id", { title: "Resolve Context7 Library ID", description: `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) - Source reputation (consider libraries with High or Medium reputation more authoritative) - Benchmark Score: Quality indicator (100 is the highest score) 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.`, inputSchema: { libraryName: z .string() .describe("Library name to search for and retrieve a Context7-compatible library ID."), }, }, async ({ libraryName }) => { const ctx = requestContext.getStore(); const searchResponse: SearchResponse = await searchLibraries( libraryName, ctx?.clientIp, ctx?.apiKey ); 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); const responseText = `Available Libraries: 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 - Source Reputation: Authority indicator (High, Medium, Low, or Unknown) - Benchmark Score: Quality indicator (100 is the highest score) - Versions: List of versions if available. Use one of those versions if the user provides a version in their query. The format of the version is /org/project/version. For best results, select libraries based on name match, source reputation, snippet coverage, benchmark score, and relevance to your use case. ---------- ${resultsText}`; return { content: [ { type: "text", text: responseText, }, ], }; } );
• packages/mcp/src/index.ts:136-140 (schema)

  Zod input schema definition for the tool: requires 'libraryName' string.
  inputSchema: { libraryName: z .string() .describe("Library name to search for and retrieve a Context7-compatible library ID."), },
• packages/mcp/src/lib/api.ts:91-119 (helper)

  Helper function that performs the actual API search for libraries matching the query and handles errors.
  export async function searchLibraries( query: string, clientIp?: string, apiKey?: string ): Promise<SearchResponse> { try { const url = new URL(`${CONTEXT7_API_BASE_URL}/v2/search`); url.searchParams.set("query", query); const headers = generateHeaders(clientIp, apiKey); const response = await fetch(url, { headers }); if (!response.ok) { const errorCode = response.status; const errorMessage = createErrorMessage(errorCode, apiKey); console.error(errorMessage); return { results: [], error: errorMessage, } as SearchResponse; } const searchData = await response.json(); return searchData as SearchResponse; } catch (error) { const errorMessage = `Error searching libraries: ${error}`; console.error(errorMessage); return { results: [], error: errorMessage } as SearchResponse; } }
• packages/mcp/src/lib/utils.ts:62-69 (helper)

  Utility function to format the search results into readable text for the tool response.
  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"); }