MastraAI•5d ago

`toUIMessageStreamResponse` also includes tool calls - how to filter out?

Hi all, I'm using AI SDK 5 with NextJS. When I call toUIMessageStreamResponse in /chat endpoint, the function returns all data, like messages and tool calls. As I want to build a public agent, I only want to return text messages, but not tool calls. How can I achieve this? I followed this tutorial here, so I guess my setup is fine: https://mastra.ai/en/examples/agents/ai-sdk-v5-integration This is the code that is relevant:

export async function POST(req: Request) {
  const { messages, id } = (await req.json()) as {
    messages: UIMessage[];
    id: string;
  };
  const testAgent = mastra.getAgent('testAgent');
  const agentResult = await testAgent.stream(messages, {
    format: 'aisdk',
    memory: {
      thread: id,
      resource: 'test',
    },
  });
  return agentResult.toUIMessageStreamResponse();
}

export async function POST(req: Request) {
  const { messages, id } = (await req.json()) as {
    messages: UIMessage[];
    id: string;
  };
  const testAgent = mastra.getAgent('testAgent');
  const agentResult = await testAgent.stream(messages, {
    format: 'aisdk',
    memory: {
      thread: id,
      resource: 'test',
    },
  });
  return agentResult.toUIMessageStreamResponse();
}

installed packages:

"@ai-sdk/openai": "^2.0.52",
"@ai-sdk/react": "^2.0.75",
"@mastra/braintrust": "^0.1.7",
"@mastra/core": "^0.21.1",
"@mastra/libsql": "^0.15.2",
"@mastra/loggers": "^0.10.16",
"@mastra/memory": "^0.15.7",
"ai": "^5.0.75",

"@ai-sdk/openai": "^2.0.52",
"@ai-sdk/react": "^2.0.75",
"@mastra/braintrust": "^0.1.7",
"@mastra/core": "^0.21.1",
"@mastra/libsql": "^0.15.2",
"@mastra/loggers": "^0.10.16",
"@mastra/memory": "^0.15.7",
"ai": "^5.0.75",

6 Replies

hefe.woizaOP•5d ago

I check the implementation, and I guess the reason why all data is included in the toUIMessageStreamResponse is, that it is using fullStream: https://github.com/mastra-ai/mastra/blob/b6a492903f63650e9b7e9d6ce95c232f24a4ce45/packages/core/src/stream/aisdk/v5/output.ts#L121

Guria•5d ago

Mastra Triager•4d ago

📝 Created GitHub issue: https://github.com/mastra-ai/mastra/issues/8966

GitHub

[DISCORD:1428677895936807026] toUIMessageStreamResponse also incl...

This issue was created from Discord post: https://discord.com/channels/1309558646228779139/1428677895936807026 Hi all, I'm using AI SDK 5 with NextJS. When I call toUIMessageStreamResponse in /...

Ward•4d ago

@hefe.woiza why not only filter it out on the frontend? If not you could write a custom transformer in your post to clean the stream

Guria•4d ago

why not only filter it out on the frontend

because:

As I want to build a public agent,

Some implementation details must be hidden I believe

hefe.woizaOP•4d ago

exactly. also, the tool is calling a rag api which is returning quite some data and i don't want to have that massive traffic

Gaming

Programming

`toUIMessageStreamResponse` also includes tool calls - how to filter out?

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