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

# Streaming & Artifacts

> Real-time streaming and artifact preview in the Playground.

## Streaming

The Playground streams responses token-by-token using Server-Sent Events (SSE). As the response is generated:

* **Tokens** appear in real-time as they're produced
* **Tool calls** are displayed inline with their name and status (`success` / `error`)
* **Model info** shows which Theo engine was selected and the resolved mode
* **Cost** updates in real-time as tokens are consumed

### Event Types

The streaming display corresponds to the SSE event types from the API:

| Event      | What You See                                   |
| ---------- | ---------------------------------------------- |
| `meta`     | Model name, resolved mode, active skills       |
| `token`    | Text appearing character by character          |
| `tool`     | Tool call badge with status                    |
| `artifact` | Preview card for generated files               |
| `done`     | Final cost, token count, follow-up suggestions |

## Artifacts

Generated files (images, code, documents) are displayed as interactive preview cards:

* **Images** — inline preview with full-resolution download link
* **Code** — syntax-highlighted with copy button and language detection
* **Documents** — download link with format badge (PDF, DOCX, PPTX, XLSX, CSV)

Artifacts are hosted on `artifacts.hitheo.ai` and the download URLs are presigned for secure access.