Redis MCP Server

Instructions

Implementation Reference

• src/tools/json.py:9-45 (handler)

  The json_set tool handler: an async function decorated with @mcp.tool() that sets a JSON value in Redis at a specified path, with optional expiration. Handles JSON parsing, Redis operations, and error handling.

  @mcp.tool()
  async def json_set(
      name: str,
      path: str,
      value: str,
      expire_seconds: Optional[int] = None,
  ) -> str:
      """Set a JSON value in Redis at a given path with an optional expiration time.
  
      Args:
          name: The Redis key where the JSON document is stored.
          path: The JSON path where the value should be set.
          value: The JSON value to store (as JSON string, or will be auto-converted).
          expire_seconds: Optional; time in seconds after which the key should expire.
  
      Returns:
          A success message or an error message.
      """
      # Try to parse the value as JSON, if it fails, treat it as a plain string
      try:
          parsed_value = json.loads(value)
      except (json.JSONDecodeError, TypeError):
          parsed_value = value
  
      try:
          r = RedisConnectionManager.get_connection()
          r.json().set(name, path, parsed_value)
  
          if expire_seconds is not None:
              r.expire(name, expire_seconds)
  
          return f"JSON value set at path '{path}' in '{name}'." + (
              f" Expires in {expire_seconds} seconds." if expire_seconds else ""
          )
      except RedisError as e:
          return f"Error setting JSON value at path '{path}' in '{name}': {str(e)}"