---
title: Streaming
product: vercel
url: /docs/ai-gateway/sdks-and-apis/openresponses/streaming
type: conceptual
prerequisites:
  - /docs/ai-gateway/sdks-and-apis/openresponses
  - /docs/ai-gateway/sdks-and-apis
related:
  - /docs/ai-gateway/sdks-and-apis/openresponses
summary: Stream responses token by token using the OpenResponses API.
install_vercel_plugin: npx plugins add vercel/vercel-plugin
---

# Streaming

The [OpenResponses API](/docs/ai-gateway/sdks-and-apis/openresponses) supports streaming to receive tokens as they're generated instead of waiting for the complete response. Set `stream: true` in your request, then read the response body as a stream of server-sent events. Each event contains a response chunk that you can display incrementally.

#### \['TypeScript'

```typescript filename="stream.ts"
const apiKey = process.env.AI_GATEWAY_API_KEY;

const response = await fetch('https://ai-gateway.vercel.sh/v1/responses', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    Authorization: `Bearer ${apiKey}`,
  },
  body: JSON.stringify({
    model: 'google/gemini-3.1-pro-preview',
    input: [
      {
        type: 'message',
        role: 'user',
        content: 'Write a haiku about debugging code.',
      },
    ],
    stream: true,
  }),
});

const reader = response.body.getReader();
const decoder = new TextDecoder();

while (true) {
  const { done, value } = await reader.read();
  if (done) break;

  const chunk = decoder.decode(value);
  const lines = chunk.split('\n');

  for (const line of lines) {
    if (line.startsWith('data:')) {
      const data = line.substring(6).trim();
      if (data) {
        const event = JSON.parse(data);
        if (event.type === 'response.output_text.delta') {
          process.stdout.write(event.delta);
        }
      }
    }
  }
}
```

#### 'Python']

```python filename="stream.py"
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.getenv('AI_GATEWAY_API_KEY'),
    base_url='https://ai-gateway.vercel.sh/v1',
)

stream = client.responses.create(
    model='google/gemini-3.1-pro-preview',
    input=[
        {
            'type': 'message',
            'role': 'user',
            'content': 'Write a haiku about debugging code.',
        },
    ],
    stream=True,
)

for event in stream:
    if event.type == 'response.output_text.delta':
        print(event.delta, end='', flush=True)
```

## Streaming events

- `response.created` - Response initialized
- `response.output_text.delta` - Text chunk received
- `response.output_text.done` - Text generation complete
- `response.completed` - Full response complete with usage stats


---

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