AWS Lambda AI streaming

An example on how to stream AI responses from a Lambda function using the AI SDK.

Uses streamText from the AI SDK to stream a response through a Lambda function URL.

{
  streaming: true
}

The handler uses awslambda.streamifyResponse to stream the AI response back to the client as it’s generated.

export const handler = awslambda.streamifyResponse(
  async (_event, responseStream) => {
    const result = streamText({
      model: "amazon/nova-micro",
      prompt: "Write a poem about clouds that is twenty paragraphs long.",
    });

    responseStream.setContentType("text/plain");
    for await (const chunk of result.textStream) {
      responseStream.write(chunk);
    }
    responseStream.end();
  },
);

Set the API key for the AI gateway.

sst secret set AiGatewayApiKey your-api-key-here

Use the “Run Client” dev command in the multiplexer to invoke the server and see the streamed response.

const server = new sst.aws.Function("Server", {
  url: true,
  streaming: true,
  timeout: "15 minutes",
  handler: "index.handler",
  environment: {
    AI_GATEWAY_API_KEY: new sst.Secret("AiGatewayApiKey").value,
  },
});

new sst.x.DevCommand("Client", {
  dev: {
    autostart: false,
    command: $interpolate`curl --no-buffer ${server.url}`,
    title: "Run Client",
  },
});

View the full example.