Rate Limiting

The conversion/rendering/validation endpoints are rate limited with two token buckets — one per client IP and one global — both refilling over a fixed window. Requests over either limit get 429 Too Many Requests.

Configuration

Variable	Default	Meaning
RATE_LIMIT_ENABLED	true	Turn rate limiting on/off
RATE_LIMIT_PER_IP	20	Max requests per client IP per window
RATE_LIMIT_GLOBAL	200	Max requests across the instance per window
RATE_LIMIT_WINDOW_SECONDS	60	Refill window for both buckets
RATE_LIMIT_TRUST_FORWARDED_FOR	false	Resolve the client IP from X-Forwarded-*

Only enable RATE_LIMIT_TRUST_FORWARDED_FOR when running behind a trusted reverse proxy — otherwise clients can spoof their IP via the header and bypass the per-IP limit.

Running with Docker

Tune the limits via environment variables:

docker run -p 8080:8080 \
  -e RATE_LIMIT_PER_IP=60 \
  -e RATE_LIMIT_GLOBAL=600 \
  -e RATE_LIMIT_WINDOW_SECONDS=60 \
  ghcr.io/bambamboole/pdf-ua-api:latest

Disable rate limiting entirely (e.g. a trusted internal deployment):

docker run -p 8080:8080 \
  -e RATE_LIMIT_ENABLED=false \
  ghcr.io/bambamboole/pdf-ua-api:latest

Behind a trusted reverse proxy, key the per-IP limit on the real client address:

docker run -p 8080:8080 \
  -e RATE_LIMIT_TRUST_FORWARDED_FOR=true \
  ghcr.io/bambamboole/pdf-ua-api:latest

When a limit is hit

Requests over either bucket receive 429 Too Many Requests with a Retry-After header telling the client how long to wait before retrying. Stay under both the per-IP and global limits to avoid throttling.