Logging

View Logs

systemd / Manual Install

# Module initialization and system logs
sudo journalctl -u nginx

# Nginx error logs (real-time)
sudo tail -f /var/log/nginx/error.log

# Cashu redemption logs
sudo tail -f /var/log/nginx/cashu_redemption.log

Docker

docker logs l402-nginx -f

Log Levels

Control verbosity via the RUST_LOG environment variable:

# Standard info logs (recommended for production)
Environment=RUST_LOG=info

# Detailed debug logs for all modules
Environment=RUST_LOG=debug

# Module-specific debug logs only (reduces noise)
Environment=RUST_LOG=ngx_l402_lib=debug,info

Structured JSON Logs

Set l402_log_format json; on a protected location to emit one JSON line per L402 access event, alongside the usual text logs. Field names match the dry-run line, so the same jq / log-aggregator queries work for both:

{"event":"l402_verify","route":"/api/data","backend":"LND","client_ip":"203.0.113.7","auth_state":"valid","method":"lightning","latency_ms":42}

Events: l402_verify (auth_state valid or invalid, method when known), l402_challenge (a 402 was issued, with price_msat and price_source), l402_challenge_error (error: backend, timeout, or panic), and l402_rate_limited (a 429, with window_secs).

Off by default (text), so existing deployments see no change. The directive is per-location: an inner l402_log_format text; overrides an outer json.