Production Defaults

Nidus production defaults are opt-in composition helpers over Axum and Tower. They return normal routers and layers so applications can inspect, replace, or reorder the boundary.

use nidus::prelude::*;

let app = Nidus::create::<AppModule>()
    .build()
    .await?
    .map_router(|router| {
        ApiDefaults::production("orders-api").apply(router)
    });

Included HTTP Defaults

• request IDs and request context
• health and readiness routes
• Prometheus-style metrics route when enabled
• CORS, body limits, timeout responses, security headers, and structured logging
• production error envelopes
• unmatched-route fallback returning the Nidus not_found JSON envelope
• OpenTelemetry trace-context helpers when the otel feature is enabled

The unmatched-route fallback is installed by default in ApiDefaults::production(...).apply(router). Missing routes therefore receive the same production envelope as handler-created HttpError::not_found(...) responses, including request ID, path, timestamp, JSON content type, and security headers. Use without_not_found_fallback() when an application installs its own Axum fallback before applying defaults.

Observability Defaults

let observability = Observability::production("orders-api")
    .version(env!("CARGO_PKG_VERSION"))
    .environment("prod")
    .prometheus()
    .tracing()
    .otel_from_env();

Automatic instrumentation applies where Nidus owns the integration point: HTTP middleware, ObservedEventBus, ObservedJobRunner, module validation, and official adapter builders. Raw SQLx queries, raw cache clients, ORMs, queues, and HTTP clients remain explicit application instrumentation.