All settings are environment variables starting with ANPR_. They can also go in a .env file in
the directory you start the service from; .env.example in the repository lists them all. Settings
are read once at start-up, so restart the service after changing one. anpr dump-config shows the
values in effect.
| Variable |
Default |
Meaning |
ANPR_PLATE_HMAC_PEPPER |
random, with a warning |
The secret plates are hashed with. At least 32 characters; anpr generate-pepper makes one. Set it in production: a random pepper changes on every restart, and then the same plate gets a different hash. |
ANPR_DATABASE_URL |
sqlite+aiosqlite:///data/anpr.db |
Where detections are stored. For PostgreSQL, install asyncpg and use postgresql+asyncpg://user:pass@host/db. |
ANPR_RETENTION_HOURS |
720 (30 days) |
Rows older than this are deleted. The check runs at start-up and then every hour. |
| Variable |
Default |
Meaning |
ANPR_DETECTOR_MODEL |
yolo-v9-t-384-license-plate-end2end |
fast-alpr detector model name, or a path to your own ONNX file. |
ANPR_DETECTOR_CONF_THRESHOLD |
0.4 |
Boxes the detector is less sure about than this are dropped. |
ANPR_OCR_MODEL |
cct-s-v2-global-model |
fast-plate-ocr model name. |
ANPR_DEVICE |
auto |
Where the OCR model runs: auto, cpu, cuda or openvino. |
ANPR_DETECT_EVERY_N_FRAMES |
3 |
On the WebSocket stream, process only every Nth frame. |
ANPR_MIN_TRACK_DWELL |
5 |
Processed frames a plate must be read on before it is confirmed. |
ANPR_SR_MIN_PLATE_WIDTH and ANPR_OCR_FALLBACK_THRESHOLD are read, but nothing uses them yet;
they are reserved for super-resolution and a second OCR engine. See the Roadmap.
| Variable |
Default |
Meaning |
ANPR_API_HOST |
0.0.0.0 |
Address anpr serve listens on. |
ANPR_API_PORT |
8000 |
Port anpr serve listens on. |
ANPR_MAX_UPLOAD_MB |
10 |
Largest file POST /api/v1/infer accepts. |
ANPR_MAX_IMAGE_PIXELS |
40000000 |
Largest decoded image, in pixels, on both the upload and the stream. 40 MP is above 8K. |
ANPR_MAX_WS_FRAME_BYTES |
4194304 (4 MB) |
Largest frame on /ws/stream. |
ANPR_API_KEY |
not set |
When set, /api/v1/* and /ws/stream need this key. At least 16 characters of letters, digits, - and _; anpr generate-api-key makes one. See HTTP API. Since 0.2.5. |
ANPR_CORS_ORIGINS |
* |
Comma-separated origins allowed to call the API from a browser. Narrow it in production. |
| Variable |
Default |
Meaning |
ANPR_LOG_LEVEL |
INFO |
DEBUG, INFO, WARNING or ERROR. |
ANPR_LOG_JSON |
false |
JSON log lines, for Loki, Elasticsearch and the like. |
OTEL_EXPORTER_OTLP_ENDPOINT |
not set |
Turns on OpenTelemetry tracing. Needs the otel extra. |
OTEL_SERVICE_NAME |
anpr |
Service name on the traces. |
