toAISdkStream()

将 Mastra 流（代理、网络或工作流）转换为与 AI SDK 兼容的流。当需要手动转换 Mastra 流以用于 AI SDK 的 createUIMessageStream() 和 createUIMessageStreamResponse() 时，请使用此函数。

🌐 Converts Mastra streams (agent, network, or workflow) to AI SDK-compatible streams. Use this function when you need to manually transform Mastra streams for use with AI SDK's createUIMessageStream() and createUIMessageStreamResponse().

当在 Mastra 提供的路由辅助功能（如 chatRoute() 或 workflowRoute()）之外构建自定义流端点时，这很有用。

🌐 This is useful when building custom streaming endpoints outside Mastra's provided route helpers such as chatRoute() or workflowRoute().

使用示例

🌐 Usage example

Next.js 应用路由示例：

🌐 Next.js App Router example:

app/api/chat/route.ts

import { mastra } from "../../mastra";
import { createUIMessageStream, createUIMessageStreamResponse } from "ai";
import { toAISdkStream } from "@mastra/ai-sdk";

export async function POST(req: Request) {
  const { messages } = await req.json();
  const myAgent = mastra.getAgent("weatherAgent");
  const stream = await myAgent.stream(messages);

  const uiMessageStream = createUIMessageStream({
    originalMessages: messages,
    execute: async ({ writer }) => {
      for await (const part of toAISdkStream(stream, { from: "agent" })) {
        await writer.write(part);
      }
    },
  });

  return createUIMessageStreamResponse({
    stream: uiMessageStream,
  });
}

tip

在 createUIMessageStream() 中将 messages 传递给 originalMessages，以避免在界面中出现重复的助手消息。详情请参见 故障排除：重复的助手消息 。

🌐 Pass messages to originalMessages in createUIMessageStream() to avoid duplicated assistant messages in the UI. See Troubleshooting: Repeated Assistant Messages for details.

参数

🌐 Parameters

第一个参数是要转换的 Mastra 流。它可以是以下之一：

🌐 The first parameter is the Mastra stream to convert. It can be one of:

• MastraModelOutput - 来自 agent.stream() 的代理流
• MastraAgentNetworkStream - 来自 agent.network() 的网络流
• MastraWorkflowStream 或 WorkflowRunOutput - 一个工作流流

第二个参数是一个选项对象：

🌐 The second parameter is an options object:

from:

'agent' | 'network' | 'workflow'

= 'agent'

The type of Mastra stream being converted.

lastMessageId?:

string

(Agent only) The ID of the last message in the conversation.

sendStart?:

boolean

= true

(Agent only) Whether to send start events in the stream.

sendFinish?:

boolean

= true

(Agent only) Whether to send finish events in the stream.

sendReasoning?:

boolean

= false

(Agent only) Whether to include reasoning-delta chunks in the stream. Set to true to stream reasoning content from models that support extended thinking.

sendSources?:

boolean

= false

(Agent only) Whether to include source citations in the output.

includeTextStreamParts?:

boolean

= true

(Workflow only) Whether to include text stream parts in the output.

messageMetadata?:

(options: { part: UIMessageStreamPart }) => Record<string, unknown> | undefined

(Agent only) A function that receives the current stream part and returns metadata to attach to start and finish chunks.

onError?:

(error: unknown) => string

(Agent only) A function to handle errors during stream conversion. Receives the error and should return a string representation.

示例

🌐 Examples

转换工作流流

🌐 Converting a workflow stream

app/api/workflow/route.ts

import { mastra } from "../../mastra";
import { createUIMessageStream, createUIMessageStreamResponse } from "ai";
import { toAISdkStream } from "@mastra/ai-sdk";

export async function POST(req: Request) {
  const { input } = await req.json();
  const workflow = mastra.getWorkflow("myWorkflow");
  const run = workflow.createRun();
  const stream = await run.stream({ inputData: input });

  const uiMessageStream = createUIMessageStream({
    execute: async ({ writer }) => {
      for await (const part of toAISdkStream(stream, { from: "workflow" })) {
        await writer.write(part);
      }
    },
  });

  return createUIMessageStreamResponse({
    stream: uiMessageStream,
  });
}

转换网络流

🌐 Converting a network stream

app/api/network/route.ts

import { mastra } from "../../mastra";
import { createUIMessageStream, createUIMessageStreamResponse } from "ai";
import { toAISdkStream } from "@mastra/ai-sdk";

export async function POST(req: Request) {
  const { messages } = await req.json();
  const routingAgent = mastra.getAgent("routingAgent");
  const stream = await routingAgent.network(messages);

  const uiMessageStream = createUIMessageStream({
    execute: async ({ writer }) => {
      for await (const part of toAISdkStream(stream, { from: "network" })) {
        await writer.write(part);
      }
    },
  });

  return createUIMessageStreamResponse({
    stream: uiMessageStream,
  });
}

转换启用推断的代理流

🌐 Converting an agent stream with reasoning enabled

app/api/reasoning/route.ts

import { mastra } from "../../mastra";
import { createUIMessageStream, createUIMessageStreamResponse } from "ai";
import { toAISdkStream } from "@mastra/ai-sdk";

export async function POST(req: Request) {
  const { messages } = await req.json();
  const reasoningAgent = mastra.getAgent("reasoningAgent");
  const stream = await reasoningAgent.stream(messages, {
    providerOptions: {
      openai: { reasoningEffort: "high" },
    },
  });

  const uiMessageStream = createUIMessageStream({
    originalMessages: messages,
    execute: async ({ writer }) => {
      for await (const part of toAISdkStream(stream, {
        from: "agent",
        sendReasoning: true,
      })) {
        await writer.write(part);
      }
    },
  });

  return createUIMessageStreamResponse({
    stream: uiMessageStream,
  });
}

使用消息元数据

🌐 Using messageMetadata

app/api/chat-with-metadata/route.ts

import { mastra } from "../../mastra";
import { createUIMessageStream, createUIMessageStreamResponse } from "ai";
import { toAISdkStream } from "@mastra/ai-sdk";

export async function POST(req: Request) {
  const { messages } = await req.json();
  const myAgent = mastra.getAgent("weatherAgent");
  const stream = await myAgent.stream(messages);

  const uiMessageStream = createUIMessageStream({
    originalMessages: messages,
    execute: async ({ writer }) => {
      for await (const part of toAISdkStream(stream, {
        from: "agent",
        messageMetadata: ({ part }) => ({
          timestamp: Date.now(),
          partType: part.type,
        }),
      })) {
        await writer.write(part);
      }
    },
  });

  return createUIMessageStreamResponse({
    stream: uiMessageStream,
  });
}

客户端流转换

🌐 Client-side stream transformation

如果你在客户端使用 Mastra 客户端 SDK（@mastra/client-js）并且想将流转换为 AI SDK 格式：

🌐 If you're using the Mastra client SDK (@mastra/client-js) on the client side and want to convert streams to AI SDK format:

client-stream-to-ai-sdk.ts

import { MastraClient } from "@mastra/client-js";
import { createUIMessageStream } from "ai";
import { toAISdkStream } from "@mastra/ai-sdk";
import type { ChunkType, MastraModelOutput } from "@mastra/core/stream";

const client = new MastraClient({
  baseUrl: "http://localhost:4111",
});

const agent = client.getAgent("weatherAgent");
const response = await agent.stream("What is the weather in Tokyo?");

// Convert the client SDK stream to a ReadableStream<ChunkType>
const chunkStream = new ReadableStream<ChunkType>({
  async start(controller) {
    await response.processDataStream({
      onChunk: async (chunk) => {
        controller.enqueue(chunk);
      },
    });
    controller.close();
  },
});

// Transform to AI SDK format
const uiMessageStream = createUIMessageStream({
  execute: async ({ writer }) => {
    for await (const part of toAISdkStream(
      chunkStream as unknown as MastraModelOutput,
      { from: "agent" }
    )) {
      await writer.write(part);
    }
  },
});

for await (const part of uiMessageStream) {
  console.log(part);
}