> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prisminference.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Streaming

> Stream OpenAI Chat Completions or Anthropic Messages from Prism.

Streaming returns model output as it is generated. Set `stream: true`, process
each event in order, and close the response when the terminal event arrives.

## OpenAI Chat Completions

```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.PRISM_API_KEY,
  baseURL: "https://api.prisminference.com/v1",
});

const stream = await client.chat.completions.create({
  model: "prism-glm53",
  messages: [{ role: "user", content: "Review this TypeScript diff: ..." }],
  stream: true,
  stream_options: { include_usage: true },
});

for await (const chunk of stream) {
  const delta = chunk.choices[0]?.delta?.content;
  if (delta != null) {
    process.stdout.write(delta);
  }

  if (chunk.usage != null) {
    console.error(`\n${chunk.usage.total_tokens} tokens`);
  }
}
```

Direct HTTP responses use Server-Sent Events:

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
curl -N "https://api.prisminference.com/v1/chat/completions" \
  -H "Authorization: Bearer $PRISM_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "prism-glm53",
    "messages": [{"role": "user", "content": "Explain this diff: ..."}],
    "stream": true,
    "stream_options": {"include_usage": true}
  }'
```

Each event starts with `data:`. The final event is `data: [DONE]`. A final
usage chunk may have an empty `choices` array.

## Anthropic Messages

```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic({
  apiKey: process.env.PRISM_API_KEY,
  baseURL: "https://api.prisminference.com",
});

const stream = client.messages.stream({
  model: "prism-glm53",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Explain this diff: ..." }],
});

stream.on("text", (text) => {
  process.stdout.write(text);
});

const message = await stream.finalMessage();
console.error(`\n${message.usage.output_tokens} output tokens`);
```

Anthropic streams typed events including `message_start`,
`content_block_delta`, `message_delta`, and `message_stop`. Use the official SDK
to assemble content blocks and tool inputs.

## Disconnects and retries

A disconnected stream may already have produced billable tokens. Do not append
a blind retry to the partial assistant message.

1. Record whether the terminal event was received.
2. If no user-visible output was consumed, retry with exponential backoff and
   jitter.
3. If partial output was consumed, either show it as interrupted or restart the
   turn as a new request.
4. For `429`, honor `Retry-After` before retrying.
5. Do not retry `400` or `401` until the request or credential is corrected.