ComfyUI MCP Server

Instructions

    Args:
        workflow: Workflow dict to execute

    Returns the prompt_id for tracking.
    Use get_history() or get_prompt_status() to check completion.
    

Implementation Reference

• src/comfy_mcp_server/tools/execution.py:143-172 (handler)

  The handler function for the 'submit_workflow' tool. It submits the workflow to ComfyUI via POST /prompt and returns the prompt_id, number, and any node_errors without waiting for completion. Includes input schema via Pydantic Field descriptions and is registered via @mcp.tool() decorator.

  @mcp.tool()
  def submit_workflow(
      workflow: dict = Field(description="Workflow to submit"),
      ctx: Context = None,
  ) -> dict:
      """Submit a workflow without waiting for completion.
  
      Args:
          workflow: Workflow dict to execute
  
      Returns the prompt_id for tracking.
      Use get_history() or get_prompt_status() to check completion.
      """
      if ctx:
          ctx.info("Submitting workflow...")
  
      status, resp = comfy_post("/prompt", {"prompt": workflow})
  
      if status != 200:
          return ErrorResponse(
              error=f"Submit failed: status {status}",
              code="SUBMIT_FAILED",
              details=resp,
          ).model_dump()
  
      return {
          "prompt_id": resp.get("prompt_id"),
          "number": resp.get("number"),
          "node_errors": resp.get("node_errors", {}),
      }

• src/comfy_mcp_server/tools/__init__.py:27-28 (registration)

  Within register_all_tools, calls register_execution_tools(mcp) which defines and registers the submit_workflow tool using @mcp.tool().

  register_workflow_tools(mcp)
  register_execution_tools(mcp)

• src/comfy_mcp_server/__init__.py:92-92 (registration)

  Top-level registration call to register_all_tools(mcp), which chains to register_execution_tools(mcp) and thus registers the submit_workflow tool.

  register_all_tools(mcp)