Observability
Metrics, tracing, and monitoring for your AI gateway.
Metrics Extension
The built-in metrics extension tracks operational counters:
import "github.com/xraph/nexus/observability"
metrics := observability.NewMetricsExtension()
gw := nexus.New(
nexus.WithExtension(metrics),
)
// Read counters
metrics.RequestsCompleted.Value() // int64
metrics.ProviderFailures.Value()
metrics.GuardrailBlocks.Value()Tracing
Add OpenTelemetry spans to every request:
nexus.WithTracer(otelTracer)The tracing middleware (priority 10) creates spans with:
- Request model and provider
- Tenant ID
- Token counts
- Cache hit/miss status
Response Headers
Every response includes diagnostic headers:
| Header | Value |
|---|---|
X-Nexus-Request-ID | Unique request identifier |
X-Nexus-Provider | Provider that served the request |
X-Nexus-Cache | HIT or MISS |
X-Nexus-Latency | Processing time in milliseconds |