RTFD (Read The F*****g Docs)

Instructions

        Fetch actual npm package documentation from npm registry README.

        USE THIS WHEN: You need installation instructions, usage examples, API reference, or quickstart guides.

        BEST FOR: Getting complete, formatted documentation for JavaScript/Node.js packages.
        Better than using curl or WebFetch because it:
        - Automatically extracts relevant sections (Installation, Usage, Examples, API)
        - Prioritizes most useful content sections
        - Already in Markdown format (npm requires Markdown READMEs)

        NOT SUITABLE FOR: External documentation sites (use docs_url from npm_metadata + WebFetch)

        Args:
            package: npm package name (e.g., "express", "react", "axios")
            max_bytes: Maximum content size, default 20KB (increase for large packages)

        Returns:
            JSON with actual documentation content, size, truncation status, version

        Example: fetch_npm_docs("express") → Returns formatted README with installation and usage
        

Implementation Reference

• src/RTFD/providers/npm.py:199-223 (handler)

  The main handler function for the 'fetch_npm_docs' MCP tool. It invokes the internal helper and serializes the result into CallToolResult format.

  async def fetch_npm_docs(package: str, max_bytes: int = 20480) -> CallToolResult:
      """
      Fetch actual npm package documentation from npm registry README.
  
      USE THIS WHEN: You need installation instructions, usage examples, API reference, or quickstart guides.
  
      BEST FOR: Getting complete, formatted documentation for JavaScript/Node.js packages.
      Better than using curl or WebFetch because it:
      - Automatically extracts relevant sections (Installation, Usage, Examples, API)
      - Prioritizes most useful content sections
      - Already in Markdown format (npm requires Markdown READMEs)
  
      NOT SUITABLE FOR: External documentation sites (use docs_url from npm_metadata + WebFetch)
  
      Args:
          package: npm package name (e.g., "express", "react", "axios")
          max_bytes: Maximum content size, default 20KB (increase for large packages)
  
      Returns:
          JSON with actual documentation content, size, truncation status, version
  
      Example: fetch_npm_docs("express") → Returns formatted README with installation and usage
      """
      result = await self._fetch_npm_docs(package, max_bytes)
      return serialize_response_with_meta(result)

• src/RTFD/providers/npm.py:100-172 (helper)

  Internal helper method containing the core logic to fetch npm registry data, process README content, extract/prioritize sections, truncate if necessary, and handle errors.

  async def _fetch_npm_docs(self, package: str, max_bytes: int = 20480) -> dict[str, Any]:
      """
      Fetch documentation content for npm package.
  
      Args:
          package: Package name
          max_bytes: Maximum content size in bytes
  
      Returns:
          Dict with content, size, source info
      """
      try:
          url = f"https://registry.npmjs.org/{package}"
  
          async with await self._http_client() as client:
              resp = await client.get(url)
              resp.raise_for_status()
              data = resp.json()
  
          # npm registry includes README in "readme" field (already Markdown)
          content = data.get("readme", "")
  
          # If no README or very short, note it
          source = "npm"
          if not content or len(content.strip()) < 100:
              content = (
                  f"# {package}\n\n{data.get('description', 'No description available.')}\n\n"
              )
              source = "npm_minimal"
  
          # Extract and prioritize sections
          sections = extract_sections(content)
          if sections:
              final_content = prioritize_sections(sections, max_bytes)
          # Fallback: simple truncation
          elif len(content.encode("utf-8")) > max_bytes:
              encoded = content.encode("utf-8")[:max_bytes]
              # Handle multi-byte characters
              while len(encoded) > 0:
                  try:
                      final_content = encoded.decode("utf-8")
                      break
                  except UnicodeDecodeError:
                      encoded = encoded[:-1]
          else:
              final_content = content
  
          return {
              "package": package,
              "content": final_content,
              "size_bytes": len(final_content.encode("utf-8")),
              "source": source,
              "truncated": len(content.encode("utf-8")) > max_bytes,
              "version": data.get("version"),
          }
  
      except httpx.HTTPStatusError as exc:
          return {
              "package": package,
              "content": "",
              "error": f"npm registry returned {exc.response.status_code}",
              "size_bytes": 0,
              "source": None,
          }
      except Exception as exc:
          return {
              "package": package,
              "content": "",
              "error": f"Failed to fetch docs: {exc!s}",
              "size_bytes": 0,
              "source": None,
          }

• src/RTFD/providers/npm.py:19-32 (registration)

  Provider metadata declaration that conditionally includes 'fetch_npm_docs' in the list of available tools.

  def get_metadata(self) -> ProviderMetadata:
      tool_names = ["npm_metadata"]
      if is_fetch_enabled():
          tool_names.append("fetch_npm_docs")
  
      return ProviderMetadata(
          name="npm",
          description="npm package registry metadata and documentation",
          expose_as_tool=True,
          tool_names=tool_names,
          supports_library_search=True,
          required_env_vars=[],
          optional_env_vars=[],
      )

• src/RTFD/providers/npm.py:225-229 (registration)

  Registration of the 'fetch_npm_docs' function in the tools dictionary returned by get_tools() method for MCP integration.

  tools = {"npm_metadata": npm_metadata}
  if is_fetch_enabled():
      tools["fetch_npm_docs"] = fetch_npm_docs
  
  return tools