By default, when you make a request to the OpenAI API, we generate the model’s entire output before sending it back in a single HTTP response. When generating long outputs, waiting for a response can take time. Streaming responses lets you start printing or processing the beginning of the model’s output while it continues generating the full response.
This guide focuses on HTTP streaming (stream=true) over server-sent events (SSE). For persistent WebSocket transport with incremental inputs via previous_response_id, see the Responses API WebSocket mode.
To start streaming responses, set stream=True in your request to the Responses endpoint:
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17import { OpenAI } from "openai";
const client = new OpenAI();
const stream = await client.responses.create({
model: "gpt-5.6",
input: [
{
role: "user",
content: "Say 'double bubble bath' ten times fast.",
},
],
stream: true,
});
for await (const event of stream) {
console.log(event);
}
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17from openai import OpenAI
client = OpenAI()
stream = client.responses.create(
model="gpt-5.6",
input=[
{
"role": "user",
"content": "Say 'double bubble bath' ten times fast.",
},
],
stream=True,
)
for event in stream:
print(event)
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23package main
import (
"context"
"fmt"
"github.com/openai/openai-go/v3"
"github.com/openai/openai-go/v3/responses"
)
func main() {
client := openai.NewClient()
stream := client.Responses.NewStreaming(context.Background(), responses.ResponseNewParams{
Model: "gpt-5.6",
Input: responses.ResponseNewParamsInputUnion{OfString: openai.String("Say 'double bubble bath' ten times fast.")},
})
for stream.Next() {
fmt.Println(stream.Current().Type)
}
if err := stream.Err(); err != nil {
panic(err)
}
}
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18using OpenAI.Responses;
#pragma warning disable OPENAI001
string key = Environment.GetEnvironmentVariable("OPENAI_API_KEY")!;
ResponsesClient client = new(key);
var responses = client.CreateResponseStreamingAsync(
"gpt-5.6",
"Say 'double bubble bath' ten times fast."
);
await foreach (StreamingResponseUpdate response in responses)
{
if (response is StreamingResponseOutputTextDeltaUpdate delta)
{
Console.Write(delta.Delta);
}
}
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17require "openai"
openai = OpenAI::Client.new
stream = openai.responses.stream(
model: "gpt-5.6",
input: [
{
role: "user",
content: "Say 'double bubble bath' ten times fast."
}
]
)
stream.each do |event|
puts(event)
end
The Responses API uses semantic events for streaming. Each event is typed with a predefined schema, so you can listen for events you care about.
For a full list of event types, see the API reference for streaming. Here are a few examples:
