mcp-nixos

Instructions

Implementation Reference

• mcp_nixos/server.py:456-536 (handler)

  The nixos_info tool handler function. It performs an exact lookup for a NixOS package or option using the Elasticsearch API on search.nixos.org, formats the results as plain text with details like version, description, homepage, license (for packages) or type, description, default, example (for options).

  async def nixos_info(name: str, type: str = "package", channel: str = "unstable") -> str:  # pylint: disable=redefined-builtin
      """Get detailed info about a NixOS package or option.
  
      Args:
          name: Name of the package or option to look up
          type: Type of lookup - "package" or "option"
          channel: NixOS channel to search in (e.g., "unstable", "stable", "25.05")
  
      Returns:
          Plain text details about the package/option or error message
      """
      info_type = type  # Avoid shadowing built-in
      if info_type not in ["package", "option"]:
          return error("Type must be 'package' or 'option'")
      channels = get_channels()
      if channel not in channels:
          suggestions = get_channel_suggestions(channel)
          return error(f"Invalid channel '{channel}'. {suggestions}")
  
      try:
          # Exact match query with correct field names
          field = "package_pname" if info_type == "package" else "option_name"
          query = {"bool": {"must": [{"term": {"type": info_type}}, {"term": {field: name}}]}}
          hits = es_query(channels[channel], query, 1)
  
          if not hits:
              return error(f"{info_type.capitalize()} '{name}' not found", "NOT_FOUND")
  
          src = hits[0].get("_source", {})
  
          if info_type == "package":
              info = []
              info.append(f"Package: {src.get('package_pname', '')}")
              info.append(f"Version: {src.get('package_pversion', '')}")
  
              desc = src.get("package_description", "")
              if desc:
                  info.append(f"Description: {desc}")
  
              homepage = src.get("package_homepage", [])
              if homepage:
                  if isinstance(homepage, list):
                      homepage = homepage[0] if homepage else ""
                  info.append(f"Homepage: {homepage}")
  
              licenses = src.get("package_license_set", [])
              if licenses:
                  info.append(f"License: {', '.join(licenses)}")
  
              return "\n".join(info)
  
          # Option type
          info = []
          info.append(f"Option: {src.get('option_name', '')}")
  
          opt_type = src.get("option_type", "")
          if opt_type:
              info.append(f"Type: {opt_type}")
  
          desc = src.get("option_description", "")
          if desc:
              # Strip HTML tags from description
              if "<rendered-html>" in desc:
                  desc = desc.replace("<rendered-html>", "").replace("</rendered-html>", "")
                  desc = re.sub(r"<[^>]+>", "", desc)
                  desc = desc.strip()
              info.append(f"Description: {desc}")
  
          default = src.get("option_default", "")
          if default:
              info.append(f"Default: {default}")
  
          example = src.get("option_example", "")
          if example:
              info.append(f"Example: {example}")
  
          return "\n".join(info)
  
      except Exception as e:
          return error(str(e))