Observability Configuration

OpenAPI

Property	Type	Default	Description
wow.openapi.enabled	Boolean	true	Enable OpenAPI spec generation

wow:
  openapi:
    enabled: true

When enabled, Wow builds the OpenAPI specification at runtime from the command and event models registered in the bounded context (RouterSpecs bean built in OpenAPIAutoConfiguration). The wow-compiler module contributes command routing metadata at compile time, but the spec itself — including routes, schemas, and the bundled Swagger UI — is assembled when the application context starts.

OpenTelemetry

Property	Type	Default	Description
wow.opentelemetry.enabled	Boolean	true	Enable OpenTelemetry tracing instrumentation of the command/event pipeline

wow:
  opentelemetry:
    enabled: true

Enabled by default (matchIfMissing = true) when the wow-opentelemetry module and the WowInstrumenter class are on the classpath. Set to false to disable distributed tracing spans across the command bus, event store, projections, and sagas.

Metrics

Property	Type	Default	Description
wow.metrics.enabled	Boolean	true	Enable Micrometer/Prometheus metrics collection

wow:
  metrics:
    enabled: true

Enabled by default (matchIfMissing = true). Governs the export of framework metrics (command processing latency, event store append counts, projection lag, etc.). Disable to suppress Wow-specific meters.

Business Intelligence Scripts

The wow.bi.script.* property tree (ClickHouse/BI script deployment) is documented on the BI Operations page.

Integration Setup

Enabling Metrics Export (Prometheus)

Wow metrics are written to Micrometer's global registry. To expose them via Prometheus, add the Spring Boot Actuator + Prometheus registry dependencies and expose the endpoint:

management:
  endpoint:
    health:
      show-details: always
      probes:
        enabled: true
  endpoints:
    web:
      exposure:
        include:
          - health
          - prometheus    # Micrometer/Prometheus scrape endpoint
          - threaddump
  metrics:
    tags:
      application: ${spring.application.name}   # common tag on all meters

springdoc:
  show-actuator: true   # include actuator endpoints in OpenAPI

implementation("org.springframework.boot:spring-boot-starter-actuator")
implementation("io.micrometer:micrometer-registry-prometheus")

Scrape the /actuator/prometheus endpoint from Prometheus. The Wow-specific meters (wow.command.*, wow.eventstore.*, wow.snapshot.*, wow.projection.*, etc.) appear alongside standard JVM/Reactor meters. See Metrics for the full catalogue.

Enabling Distributed Tracing (OpenTelemetry)

The recommended way to enable tracing is the OpenTelemetry Java Agent, which bootstraps GlobalOpenTelemetry before the Spring context starts:

java -javaagent:opentelemetry-javaagent.jar \
     -Dotel.service.name=${spring.application.name} \
     -Dotel.exporter.otlp.endpoint=http://otel-collector:4317 \
     -jar your-app.jar

Add wow-opentelemetry to your dependencies. You also need wow-spring-boot-starter (with the opentelemetry-support capability) — WowOpenTelemetryAutoConfiguration lives in the starter, not the module. The auto-configuration detects the agent's initialized GlobalOpenTelemetry and registers the Wow tracing filters and decorators automatically. Set wow.opentelemetry.enabled=false only to disable Wow's spans while keeping the agent's other instrumentation.

implementation("me.ahoo.wow:wow-opentelemetry")

See Observability for the instrumentation coverage and OpenTelemetry Extension for the instrumenter list.