Nest.js

You can use the AI SDK in a Nest.js server to generate and stream text and objects to the client.

Examples

The examples show how to implement a Nest.js controller that uses the AI SDK to stream text and objects to the client.

Full example: github.com/vercel/ai/examples/nest

Data Stream

You can use the pipeDataStreamToResponse method to get a data stream from the result and then pipe it to the response.

app.controller.ts
import { Controller, Post, Res } from '@nestjs/common';
import { openai } from '@ai-sdk/openai';
import { streamText } from 'ai';
import { Response } from 'express';
@Controller()
export class AppController {
@Post()
async example(@Res() res: Response) {
const result = await streamText({
model: openai('gpt-4o'),
prompt: 'Invent a new holiday and describe its traditions.',
});
result.pipeDataStreamToResponse(res);
}
}

Data Stream With Stream Data

pipeDataStreamToResponse can be used with StreamData to send additional data to the client.

app.controller.ts
import { Controller, Post, Res } from '@nestjs/common';
import { openai } from '@ai-sdk/openai';
import { StreamData, streamText } from 'ai';
import { Response } from 'express';
@Controller()
export class AppController {
@Post()
async example(@Res() res: Response) {
const data = new StreamData();
data.append('initialized call');
const result = await streamText({
model: openai('gpt-4o'),
prompt: 'Invent a new holiday and describe its traditions.',
onFinish() {
data.append('call completed');
data.close();
},
});
result.pipeDataStreamToResponse(res, { data });
}
}

Text Stream

You can use the pipeTextStreamToResponse method to get a text stream from the result and then pipe it to the response.

app.controller.ts
import { Controller, Post, Res } from '@nestjs/common';
import { openai } from '@ai-sdk/openai';
import { streamText } from 'ai';
import { Response } from 'express';
@Controller()
export class AppController {
@Post()
async example(@Res() res: Response) {
const result = await streamText({
model: openai('gpt-4o'),
prompt: 'Invent a new holiday and describe its traditions.',
});
result.pipeTextStreamToResponse(res);
}
}