Metrics

Hedwig exposes Prometheus-compatible metrics over HTTP when configured.

Enable metrics

[server.metrics]
bind = "0.0.0.0:9090"  # HTTP listener for /metrics

• Endpoint: GET /metrics
• Protocol: plain HTTP (place behind a firewall or reverse proxy if exposed)

Quick check

curl -s http://localhost:9090/metrics | head

Exported metrics (examples)

• hedwig_queue_depth
• hedwig_emails_received_total
• hedwig_emails_sent_total
• hedwig_worker_jobs_processed_total
• hedwig_send_attempts_total{domain,status} (at most 64 distinct domains; the rest report as domain="other")
• hedwig_send_latency_seconds (one histogram for all destinations, no domain label)
• hedwig_mta_sts_policy_fetch_total{result}
• hedwig_mta_sts_enforcement_total{mode,result}
• hedwig_mta_sts_cache_size