MCP Echo Service

Instructions

Implementation Reference

• src/mcp_echo/server.py:87-117 (handler)

  The handler function for the 'echo_with_delay' tool, which performs a sleep and returns timing data.

  async def echo_with_delay(
      message: str, delay_seconds: float = 1.0, ctx: Context | None = None
  ) -> EchoDelayResponse:
      """Echo back a message after a simulated delay.
  
      Args:
          message: The message to echo back
          delay_seconds: Delay duration in seconds (max 5.0 seconds)
          ctx: MCP context
  
      Returns:
          Echo response with timing information
      """
      # Limit delay to maximum of 5 seconds for safety
      delay_seconds = min(float(delay_seconds), 5.0)
  
      if ctx:
          await ctx.info(f"Echoing with {delay_seconds}s delay: {message[:50]}...")
  
      start_time = datetime.now(UTC)
      time.sleep(delay_seconds)
      end_time = datetime.now(UTC)
  
      return EchoDelayResponse(
          original_message=message,
          echoed_message=message,
          requested_delay=delay_seconds,
          actual_delay=(end_time - start_time).total_seconds(),
          start_time=start_time.isoformat(),
          end_time=end_time.isoformat(),
          timestamp=end_time.isoformat(),

• src/mcp_echo/server.py:86-86 (registration)

  Registration of 'echo_with_delay' tool using the @mcp.tool() decorator.

  @mcp.tool()

• src/mcp_echo/api_models.py:19-28 (schema)

  Pydantic model defining the response schema for the 'echo_with_delay' tool.

  """Response model for echo_with_delay tool."""
  
  original_message: str = Field(..., description="The original message sent")
  echoed_message: str = Field(..., description="The echoed message")
  requested_delay: float = Field(..., description="Requested delay in seconds")
  actual_delay: float = Field(..., description="Actual delay experienced in seconds")
  start_time: str = Field(..., description="ISO 8601 timestamp when delay started")
  end_time: str = Field(..., description="ISO 8601 timestamp when delay ended")
  timestamp: str = Field(..., description="ISO 8601 timestamp of the operation")