Mastra•4d ago

Streaming Workflow Run in Chat

Hey- I am still a little confused how I can stream a workflow with in a chat when my agent triggers is. I have looked into AI SDK and Copilot kit. As I see it rn, both those platofrms have their version of a useChat hook which connects an agent to the frontend. They provide hooks for rendering uis when tools are called wtc. In mastra I have an agent with 2 workflows attached to it, and my end goal is that I want to be able to trigger a workflow, have the user accept the workflow, then stream teh workflow progress within the chat as a ui, and then produce an output that can be iterated on. I have a useWorkflowExecution hook that I ahve made to handle workflow streaming when ran in isolation, but I am still struggling how to run workflows properly within chat. Are there any working examples of this?

_roamin_•12/15/25, 9:25 PM

Hey @wiz2202 ! How do you call your agent? Are you using

writer.write

writer.write

in your workflow steps to stream data to your frontend?

wiz2202OP•12/15/25, 9:46 PM

Hey @_roamin_

I am using the agent.stream and I have a workflwo atached to that agent. I currently have an api that connects with copilot kit

mport {
CopilotRuntime,
ExperimentalEmptyAdapter,
copilotRuntimeNextJSAppRouterEndpoint,
} from "@copilotkit/runtime";
import { MastraAgent } from "@ag-ui/mastra";
import { NextRequest } from "next/server";
import { mastra } from "@/mastra";

// Use ExperimentalEmptyAdapter for agent-only mode (no direct LLM calls from CopilotKit)
// The Mastra agents handle all LLM interactions
const serviceAdapter = new ExperimentalEmptyAdapter();

export const POST = async (req: NextRequest) => {
// Create the CopilotRuntime instance with Mastra agents via AG-UI protocol
// This exposes all registered Mastra agents to the CopilotKit frontend
const runtime = new CopilotRuntime({
agents: MastraAgent.getLocalAgents({ mastra }),
});

const { handleRequest } = copilotRuntimeNextJSAppRouterEndpoint({
runtime,
serviceAdapter,
endpoint: "/api/copilotkit",
});

return handleRequest(req);
};

wiz2202OP•12/15/25, 9:48 PM

I just want to be able to render the step start and step end in the ui so I can render progress bars like I have rn as stand alone values buti in the chat for a better ux

_roamin_•12/15/25, 10:14 PM

When you attach a workflow to an agent, the workflow is basically converted into a "tool", so if you want to get info about the workflow you need to look at the tooltool related chunks in your stream. For example, if my agent calls a workflow, you can see the workflow status in the tool-outputtool-output chunks like below:

{
  type: 'tool-output',
  runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
  from: 'USER',
  payload: {
    output: {
      type: 'workflow-step-start',
      runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
      from: 'WORKFLOW',
      payload: [Object]
    },
    toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2',
    toolName: 'workflow-calculateWorkflow'
  }
}
{
  type: 'tool-output',
  runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
  from: 'USER',
  payload: {
    output: {
      type: 'workflow-step-result',
      runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
      from: 'WORKFLOW',
      payload: [Object]
    },
    toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2',
    toolName: 'workflow-calculateWorkflow'
  }
}
{
  type: 'tool-output',
  runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
  from: 'USER',
  payload: {
    output: {
      type: 'workflow-finish',
      runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
      from: 'WORKFLOW',
      payload: [Object]
    },
    toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2',
    toolName: 'workflow-calculateWorkflow'
  }
}

{
  type: 'tool-output',
  runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
  from: 'USER',
  payload: {
    output: {
      type: 'workflow-step-start',
      runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
      from: 'WORKFLOW',
      payload: [Object]
    },
    toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2',
    toolName: 'workflow-calculateWorkflow'
  }
}
{
  type: 'tool-output',
  runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
  from: 'USER',
  payload: {
    output: {
      type: 'workflow-step-result',
      runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
      from: 'WORKFLOW',
      payload: [Object]
    },
    toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2',
    toolName: 'workflow-calculateWorkflow'
  }
}
{
  type: 'tool-output',
  runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
  from: 'USER',
  payload: {
    output: {
      type: 'workflow-finish',
      runId: '105e042e-f1db-4b5b-93b8-31b2592651e3',
      from: 'WORKFLOW',
      payload: [Object]
    },
    toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2',
    toolName: 'workflow-calculateWorkflow'
  }
}

Do you have access to the stream chunks?

wiz2202OP•12/15/25, 10:18 PM

ohh yes- this might be more of a question for the copilot kit team then. Right now I have their useCoAgent hook and my own custom useWorkflowExecution hook for running workflow in isolation, but I need to figure out how to combine these, which may require me doing so with their useActions tool call to render different steps

wiz2202OP•12/15/25, 10:18 PM

thanks @_roamin_

_roamin_•12/15/25, 10:26 PM

Hmm, you're right, it could also be something that's not being handled in the ag-ui package at the moment, although it's a tool call in the end

wiz2202OP•12/15/25, 10:37 PM

yep- thats helpful. Thank you. Will report back if I get it working

{ type: 'tool-output', runId: '105e042e-f1db-4b5b-93b8-31b2592651e3', from: 'USER', payload: { output: { type: 'workflow-step-start', runId: '105e042e-f1db-4b5b-93b8-31b2592651e3', from: 'WORKFLOW', payload: [Object] }, toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2', toolName: 'workflow-calculateWorkflow' } } { type: 'tool-output', runId: '105e042e-f1db-4b5b-93b8-31b2592651e3', from: 'USER', payload: { output: { type: 'workflow-step-result', runId: '105e042e-f1db-4b5b-93b8-31b2592651e3', from: 'WORKFLOW', payload: [Object] }, toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2', toolName: 'workflow-calculateWorkflow' } } { type: 'tool-output', runId: '105e042e-f1db-4b5b-93b8-31b2592651e3', from: 'USER', payload: { output: { type: 'workflow-finish', runId: '105e042e-f1db-4b5b-93b8-31b2592651e3', from: 'WORKFLOW', payload: [Object] }, toolCallId: 'call_Xs3EwiGAOh8jMxqG7oWt7Vf2', toolName: 'workflow-calculateWorkflow' } }