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

# Streaming

> Stream responses token-by-token over server-sent events.

Set `stream: true` to receive tokens as they're generated over SSE instead of waiting for the full response.

## Request

```json theme={null}
{
  "model": "gpt-5",
  "messages": [{"role": "user", "content": "Write a haiku about coding"}],
  "stream": true
}
```

## Code examples

<CodeGroup>
  ```python Python theme={null}
  import os, requests, json

  r = requests.post("https://www.ninjachat.ai/api/v1/chat",
      headers={"Authorization": f"Bearer {os.environ['NINJACHAT_API_KEY']}"},
      json={
          "model": "auto",
          "messages": [{"role": "user", "content": "Write a haiku about coding"}],
          "stream": True,
          "include_routing": True,
      },
      stream=True
  )

  for line in r.iter_lines():
      if not line:
          continue
      text = line.decode("utf-8")
      if text.startswith("data: ") and text != "data: [DONE]":
          chunk = json.loads(text[6:])
          if "routing" in chunk:
              print(f"Routed to: {chunk['routing']['resolved']}", flush=True)
          token = chunk.get("choices", [{}])[0].get("delta", {}).get("content", "")
          print(token, end="", flush=True)
  print()
  ```

  ```javascript Node.js theme={null}
  const r = await fetch("https://www.ninjachat.ai/api/v1/chat", {
    method: "POST",
    headers: {
      "Authorization": `Bearer ${process.env.NINJACHAT_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      model: "gpt-5",
      messages: [{ role: "user", content: "Write a haiku about coding" }],
      stream: true,
    }),
  });

  const reader = r.body.getReader();
  const decoder = new TextDecoder();
  while (true) {
    const { done, value } = await reader.read();
    if (done) break;
    for (const line of decoder.decode(value).split("\n")) {
      if (line.startsWith("data: ") && line !== "data: [DONE]") {
        const token = JSON.parse(line.slice(6)).choices?.[0]?.delta?.content || "";
        process.stdout.write(token);
      }
    }
  }
  ```
</CodeGroup>

## SSE format

Each event is a `data:` line containing a JSON chunk. The stream ends with `data: [DONE]`.

```
data: {"choices":[{"delta":{"content":"The"}}]}
data: {"choices":[{"delta":{"content":" capital"}}]}
data: [DONE]
```

When using smart routing (`model: "auto"`), the first chunk includes a `routing` object with the resolved model — before any content tokens arrive.

## Notes

* Streaming works with all models, smart routing variants, and sessions.
* Response caching is automatically disabled for streaming requests.
* Billing is the same as non-streaming — you're charged at the resolved model's rate.