# Common Mistakes

- Do not commit `.env`; it is intentionally ignored and should stay local.
- Use `POST /v1/chat/completions` with JSON only. Multipart upload is not implemented.
- For image input, send either an `http(s)` URL, a data URL, or raw base64 on `image_url.url`.
- For audio input, send base64 on `input_audio.data` with `format: "mp3"` or `"wav"`, or send `input_audio.url` and let the proxy download and convert it to mp3.
- Streamed chat completions are passed through directly, so proxy-hosted media URLs are only added on non-stream responses.
- Proxy-hosted media files are stored in memory and expire after `MEDIA_TTL_SECONDS`.
- The demo UI in `public/chatclient/` assumes the proxy is available on the same origin unless you change the endpoint field manually.
- Keep modules small and focused; this project follows the principle of simple modules with clear responsibility.