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

# Streaming

> Receive answers incrementally over Server-Sent Events.

Set `"stream": true` on [Query](/api-reference/chat/query) or [Send Message](/api-reference/chat/send-message) to receive the response as a `text/event-stream` of named Server-Sent Events.

```bash cURL theme={null}
curl -N -X POST https://api.doctly.ai/api/v1/query \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"collection_ids": ["..."], "query": "What is the warranty period?", "stream": true}'
```

## Events

Each SSE frame carries an `event` name and a JSON `data` payload.

### `status`

Progress updates while the answer is being researched.

```text theme={null}
event: status
data: {"step": "retriever", "heading": "Searching your documents"}
```

### `delta`

Incremental answer text. Concatenate `text` values in order to build the running answer.

```text theme={null}
event: delta
data: {"text": "The warranty period is "}
```

### `complete`

Terminal event with the final answer and citations. For session messages it also carries the stored message `id` and `session_id`.

```text theme={null}
event: complete
data: {"id": 42, "session_id": "b31c9a52-...", "answer": "The warranty period is 24 months [citation:3:12].", "citations": [...]}
```

### `error`

Terminal event when generation fails mid-stream.

```text theme={null}
event: error
data: {"error": {"type": "api_error", "message": "..."}}
```

## Keepalives

During long retrieval steps the stream emits SSE comment lines (`: keepalive`). Standards-compliant SSE parsers discard comments automatically; no handling is needed.

## Consuming the stream

The final `delta`-accumulated text may differ slightly from the `complete` event's `answer` (the complete answer is authoritative). Always end on `complete` or `error`; if the connection drops earlier, the partial assistant message is stored with `status: "partial"` and can be fetched via [Get Messages](/api-reference/chat/get-messages).