010-documentation-context

External Library Documentation Requirements

• ALWAYS Use Context7 Before Using External Libraries

  • The agent MUST retrieve and review documentation via Context7 before implementing any code that uses an external library
  • This applies to ALL libraries not part of the standard language libraries
  • No exceptions - even for commonly known libraries like React, Express, or Lodash

• Two-Step Documentation Retrieval Process

  // ✅ DO: ALWAYS follow this exact two-step process
  // Step 1: Resolve the library name to a Context7-compatible ID
  const libraryIdResponse =
    await mcp_context7_resolve-library-id({
      libraryName: "express",
    });
  
  // Step 2: Get the documentation using the resolved ID
  const docsResponse =
    await mcp_context7_get-library-docs({
      context7CompatibleLibraryID: libraryIdResponse.libraryId,
      tokens: 10000, // Adjust based on documentation needs
      topic: "routing", // Optional: focus on specific area
    });
  
  // ❌ DON'T: Skip the resolution step
  // ❌ DON'T: Use hardcoded library IDs
  // ❌ DON'T: Proceed with implementation without review
  

• Never Skip Documentation Retrieval

  • Documentation MUST be retrieved even for seemingly simple APIs
  • Do not rely on previously cached knowledge for current implementations
  • Never make assumptions about library interfaces, verify with current documentation

• Document First, Implement Second

  // ✅ DO: Review documentation BEFORE writing implementation code
  // 1. Identify library need
  // 2. Retrieve documentation
  // 3. Review relevant sections
  // 4. THEN implement solution
  
  // ❌ DON'T: Implementation without documentation
  const app = express(); // WRONG - Documentation not retrieved first
  app.get("/", (req, res) => res.send("Hello"));
  

• Verify API Compatibility

  • Always check current API version compatibility
  • Validate method signatures against retrieved documentation
  • Verify required dependencies and peer dependencies

• Handle Documentation Response Properly

  // ✅ DO: Properly handle the documentation response
  const docsResponse =
    await mcp_context7_get-library-docs({
      context7CompatibleLibraryID: "vercel/nextjs",
    });
  
  // Extract relevant information
  const sections = docsResponse.content.sections;
  const examples = sections.filter((s) => s.type === "example");
  const apiDocs = sections.filter((s) => s.type === "api");
  
  // Use this for implementation guidance
  // ...
  
  // ❌ DON'T: Ignore retrieved documentation
  // ❌ DON'T: Proceed with implementation based on assumptions
  

• Required Documentation Review Checklist

  • Core API functions and methods must be verified
  • Method signatures and parameters must be validated
  • Return values and types must be confirmed
  • Required configuration must be identified
  • Common patterns and examples must be analyzed

• Example Implementation Flow

  // ✅ DO: Follow this implementation flow
  
  // 1. Identify need for external library
  // "I need to implement JWT authentication in Express"
  
  // 2. Resolve library IDs for ALL needed libraries
  const expressLibrary =
    await mcp_context7_resolve-library-id({
      libraryName: "express",
    });
  
  const jwtLibrary =
    await mcp_context7_resolve-library-id({
      libraryName: "jsonwebtoken",
    });
  
  // 3. Retrieve documentation for ALL libraries
  const expressDocs =
    await mcp_context7_get-library-docs({
      context7CompatibleLibraryID: expressLibrary.libraryId,
    });
  
  const jwtDocs =
    await mcp_context7_get-library -
    docs({
      context7CompatibleLibraryID: jwtLibrary.libraryId,
      topic: "authentication",
    });
  
  // 4. Review documentation and extract implementation details
  // 5. Create implementation with proper reference to documentation
  
  // ❌ DON'T: Skip any library in multi-library implementations
  

• Documentation First for Dependency Resolution