| `PREVIEW_HOMESERVER` | The homeserver to use for the previews. | `https://matrix.nexy7574.co.uk` | The host name of the request URL. |
| `PREVIEW_HOST` | The host IP/Name to listen to. | `192.168.0.2` | `0.0.0.0` |
| `PREVIEW_PORT` | The port to listen to. | `8080` | `2226` |
| `PREVIEW_PROXY` | A HTTP/HTTPS/SOCKS4/SOCKS5 proxy to use for all network requests. | `http://localhost:1080` | null |
| `PREVIEW_USER_AGENT` | The user agent to use for all network requests. Must be one of `google`, `bing`, `duckduckgo`, `firefox`, `chrome`, `twitter`, `facebook`, `honest` (uses a unique user agent) | `firefox` | `google` |
| `PREVIEW_MAX_MEDIA_MB` | The maximum size of media to proxy in megabytes. Media larger than this downloaded from sites will not be re-uploaded to the homeserver's media repo, and as such cannot be used in the preview response. | `10` | `50` |
| `PREVIEW_DATABASE_URL` | The sqlite://, postgres://, or mysql:// URL to use for the database. | `postgres://user:pass@localhost:5432/dip` | `sqlite:///app/data/db.sqltie3` |
| `FORWARDED_ALLOW_IPS` | The list of reverse proxy IPs to trust. See [Uvicorn docs](https://www.uvicorn.org/settings/#http) | * | `127.0.0.1` |
| `LOG_LEVEL` | The log level to use. One of `DEBUG`, `INFO`, `WARNING`, `ERROR`, `CRITICAL`. | `INFO` | `INFO` |
| `LOG_DEBUG_TIDY` | When `LOG_LEVEL` is `DEBUG`, silences some really noisy loggers (like HTTP request loggers) to help you debug this program, not a dependency). | `true` | `false` |