WebSocket support for OpenAI Responses API live on AI Gateway

AI Gateway now supports WebSocket mode for the OpenAI Responses API. You can keep a persistent connection open and continue each turn by sending only new input items plus previous_response_id, instead of re-sending the full context over a fresh HTTP request every turn.

OpenAI reports up to ~40% faster end-to-end execution on WebSockets for agentic rollouts with 20 or more tool calls.

Copy link to headingRoute Responses API traffic over WebSocket

The Responses route opens at GET /v1/responses and accepts raw response.create frames over a persistent WebSocket connection. The mode is compatible with store=false and Zero Data Retention, and follows OpenAI's WebSocket mode specification upstream.

import WebSocket from 'ws';
const ws = new WebSocket('wss://ai-gateway.vercel.sh/v1/responses', {
  headers: { Authorization: `Bearer ${process.env.AI_GATEWAY_API_KEY}` },
});
ws.on('open', () => ws.send(JSON.stringify({
  type: 'response.create',
  model: 'openai/gpt-5.6-sol',
  store: false,
  input: 'Pick a gemstone.',
})));
ws.on('message', (data) => {
  const event = JSON.parse(data);
  if (event.type === 'response.completed') {
    ws.send(JSON.stringify({
      type: 'response.create',
      model: 'openai/gpt-5.6-sol',
      store: false,
      previous_response_id: event.response.id,
      input: 'Which gemstone did you pick?',
    }));
  }
});

See the AI Gateway documentation for setup and the full route list.