OpenFeature correlation

TL;DR. Stamps every OpenFeature evaluation onto MDC and the active span. "Did this bug only hit users on the new flag?" becomes a one-line query.

Feature flags are the most under-instrumented thing in most production systems. "Did the bug only affect users with the new checkout flow on?" should be a one-line query — but only if every flag evaluation lands on the trace and the log line.

Pulse stamps every OpenFeature evaluation onto MDC and the active span automatically. No SDK calls, no manual hook registration.

What you get

Every log line touched by a flag evaluation carries it:

{
  "message": "rendering checkout",
  "trace_id": "...",
  "feature_flag.key": "new_checkout",
  "feature_flag.variant": "treatment"
}

So "slow checkout requests where new_checkout=treatment" becomes a single LogQL query, instead of grepping log files and joining by trace ID.

Turn it on

Nothing. When dev.openfeature:sdk is on the classpath, Pulse registers the hook automatically.

What it adds

Where	Field
MDC	feature_flag.key, feature_flag.variant, feature_flag.provider_name
Active span	OTel-semconv feature_flag event

If the optional dev.openfeature.contrib.hooks:otel hook is also on the classpath, Pulse registers it too — so consumers don't have to wire it themselves.

When to skip it

pulse:
  open-feature:
    enabled: false

Suppresses both the MDC hook and the OTel hook registration.

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Source: PulseOpenFeatureMdcHook.java · Status: Stable since 1.0.0