WeMo MCP Server

Instructions

Dictionary containing:
- exists: Whether cache file exists
- path: Path to cache file
- age_seconds: Age of cache in seconds
- expired: Whether cache has expired
- device_count: Number of devices in cache
- ttl_seconds: Time-to-live for cache entries

Implementation Reference

• src/wemo_mcp_server/server.py:580-604 (handler)

  The get_cache_info MCP tool handler, which calls the cache manager's get_cache_info method.

  async def get_cache_info() -> dict[str, Any]:
      """Get information about the persistent device cache.
  
      Returns information about the cache file including age, expiration status,
      and device count. Useful for determining if a rescan is needed.
  
      Returns
      -------
          Dictionary containing:
          - exists: Whether cache file exists
          - path: Path to cache file
          - age_seconds: Age of cache in seconds
          - expired: Whether cache has expired
          - device_count: Number of devices in cache
          - ttl_seconds: Time-to-live for cache entries
  
      """
      try:
          cache_info = _cache_manager.get_cache_info()
          cache_info["memory_cache_size"] = len(_device_cache)
          return cache_info
      except Exception as e:
          logger.error(f"Error getting cache info: {e}", exc_info=True)
          return build_error_response(e, "Get cache info")

• src/wemo_mcp_server/cache.py:164-202 (handler)

  The DeviceCache method that performs the actual logic for getting cache information from the file system.

  def get_cache_info(self) -> dict[str, Any]:
      """Get information about the current cache.
  
      Returns
      -------
          Dictionary with cache metadata
  
      """
      if not self.cache_file.exists():
          return {
              "exists": False,
              "path": str(self.cache_file),
              "ttl_seconds": self.ttl_seconds,
          }
  
      try:
          with self.cache_file.open() as f:
              data = json.load(f)
  
          cache_age = time.time() - data.get("timestamp", 0)
          return {
              "exists": True,
              "path": str(self.cache_file),
              "version": data.get("version"),
              "device_count": data.get("device_count", 0),
              "age_seconds": round(cache_age, 2),
              "ttl_seconds": self.ttl_seconds,
              "expired": cache_age > self.ttl_seconds,
              "created": data.get("timestamp"),
          }
  
      except (json.JSONDecodeError, OSError, KeyError) as e:
          return {
              "exists": True,
              "path": str(self.cache_file),
              "error": str(e),
              "ttl_seconds": self.ttl_seconds,
          }