MCP Echo Service

Instructions

Implementation Reference

• src/mcp_echo/server.py:59-83 (handler)

  The main handler function for the `echo_message` tool.

  async def echo_message(
      message: str, uppercase: bool = False, ctx: Context | None = None
  ) -> EchoMessageResponse:
      """Echo back a message with optional formatting.
  
      Args:
          message: The message to echo back
          uppercase: Whether to convert the message to uppercase
          ctx: MCP context
  
      Returns:
          Complete echo response with metadata
      """
      if ctx:
          await ctx.info(f"Echoing message (uppercase={uppercase}): {message[:50]}...")
  
      result_message = message.upper() if uppercase else message
  
      return EchoMessageResponse(
          original_message=message,
          echoed_message=result_message,
          uppercase_applied=uppercase,
          message_length=len(message),
          timestamp=datetime.now(UTC).isoformat(),
      )

• src/mcp_echo/server.py:58-58 (registration)

  Registration of the `echo_message` tool using the `@mcp.tool()` decorator.

  @mcp.tool()

• src/mcp_echo/api_models.py:8-12 (schema)

  Response schema definition for the `echo_message` tool.

  class EchoMessageResponse(BaseModel):
      """Response model for echo_message tool."""
  
      original_message: str = Field(..., description="The original message sent")
      echoed_message: str = Field(..., description="The echoed message (possibly transformed)")