Connect the dd-openfeature SDK to the agent

[PerfectSlayer]

What Does This Do

Ships the standalone dd-openfeature SDK in place of the agent-coupled provider:

• New dd-openfeature-connector instrumentation: detects the SDK and plugs the agent backend in through the bootstrap FeatureFlaggingGateway (Remote Configuration documents, event platform proxy, telemetry health metrics, span enrichment).
• Agent backend (feature-flagging-lib) now forwards raw configuration documents and event payloads (FeatureFlagsBackend, EventProxy).
• Removes feature-flagging-api and the agent-side agentless configuration/event code now owned by the SDK, plus their config keys. Removes the feature-flagging-config module, its keys moving to dd-trace-api.
• Publishes :dd-openfeature as com.datadoghq:dd-openfeature; keeps datadog.trace.api.openfeature.Provider as a deprecated alias.
• System tests build the matching dd-openfeature jar.

Motivation

The SDK must not share dd-trace-java internals, and SDK (customer build time) and agent (SSI runtime) versions must be able to differ (APMLP-1512). See dd-openfeature/README.md.

Additional Notes

Most of the diff (~17k lines) deletes agent-side code and tests that now live in the dd-openfeature SDK (#12840–#12843). Review closely the new connector instrumentation, FeatureFlaggingGateway, FeatureFlagsBackend, EventProxy, RemoteConfigServiceImpl and FeatureFlaggingSystem; the rest is mechanical or deletions.

New files

File	Notes
dd-openfeature-connector/build.gradle	New instrumentation module; helpers in a java11 source set compiled against :dd-openfeature (compileOnly). TODO: add a muzzle directive once the SDK is published
DDOpenFeatureInstrumentation	InstrumenterModule("openfeature") for the FEATURE_FLAGS target system, instruments Connectors.detect()
DetectConnectorAdvice	Exit advice replacing the detected connector with JavaAgentConnector.connect(fallback)
JavaAgentConnector	SDK Connector backed by FeatureFlaggingGateway.backend(), falls back to the SDK default without backend
AgentConfigurationSource, AgentEventProxy, AgentHealthMetrics, AgentSpanEnricher	Thin adapters from the SDK connector SPI to the gateway Backend. AgentEventProxy throws EventProxyUnavailableException on definitive rejection so the SDK switches to direct intake
DDOpenFeatureInstrumentationTest, …DisabledForkedTest	Connector detection, fallback, delegation of each SPI; no instrumentation when Feature Flags is disabled
ConfigurationResolutionParityTest	Agent InstrumenterConfig and SDK Settings must resolve enablement and source identically
lib FeatureFlagsBackend	Agent FeatureFlaggingGateway.Backend: settings from Config (agent defaults for API key, site, env, service, version; others from configProvider()), lazy RemoteConfigServiceImpl, event proxy delegation, health metrics through CoreMetricCollector, span enrichment through SpanEnrichmentWriter. start() registers RC early only for the remote_config source
lib EventProxy	One lazy agent EVP proxy client per route; NEVER_RETRY when the SDK can fall back to direct intake. ConnectException / 403 / 404 / 405 mean unavailable, other IOExceptions are rethrown
lib FeatureFlagsBackendTest, EventProxyTest	Unit tests of the above
dd-openfeature/README.md	User documentation and contributor design notes
datadog/trace/api/openfeature/Provider + ProviderTest	@Deprecated alias of com.datadog.openfeature.Provider (and Options) for source compatibility

Significant changes

File	Changes
bootstrap FeatureFlaggingGateway	Static listener hub replaced by a single registered Backend with JDK-only types: setting, isRemoteConfigAvailable, subscribeRemoteConfig(Consumer<byte[]>), isEventProxyAvailable, postEvent(route, json), count, enrichSerialId, enrichRuntimeDefault. Config / activation / exposure / span enrichment listeners, cached configuration, flag evaluation writer and enqueue toggle removed
lib RemoteConfigServiceImpl	No UFC parsing anymore: forwards raw FFE_FLAGS documents (null on removal) to subscribers, replays the current one to late subscribers. Idempotent start() / close()
lib SpanEnrichmentWriter	No longer a gateway listener; exposes serialId(...) / runtimeDefault(...) called by FeatureFlagsBackend
agent FeatureFlaggingSystem	~200 → ~60 lines: builds, starts (rolls back on failure) and registers FeatureFlagsBackend. Agentless activation, writers, kill switch and source factory moved to the SDK
lib FeatureFlagEventType	logName removed
Config, ConfigDefaults, ConfigTest	Configuration source returned as the FeatureFlaggingSource enum. Agentless base URL, poll interval and request timeout removed; the SDK Settings reads and validates them, still resolvable from agent config through Backend.setting()
FeatureFlaggingConfig	Moved from feature-flagging-config to dd-trace-api; span enrichment, evaluation counts and agentless keys removed (owned by the SDK)
dd-openfeature/build.gradle.kts	Publishing enabled (com.datadoghq:dd-openfeature), Automatic-Module-Name, Java 11 javadoc, compareToReferenceJar disabled
Tests: RemoteConfigServiceImplTest, SpanEnrichmentWriterTest, FeatureFlaggingSystemTest, FeatureFlaggingGatewayTest	Rewritten for raw document forwarding, new enrichment entry points, backend registration / rollback

Mechanical changes

• run-system-tests.yaml, .gitlab-ci.yml: build :dd-openfeature:jar so system tests use the matching SDK
• settings.gradle.kts: drops feature-flagging-api, includes dd-openfeature-connector
• .github/CODEOWNERS: adds /dd-java-agent/instrumentation/datadog/openfeature/
• metadata/agent-jar-checks.properties: adds the openfeature integration
• metadata/supported-configurations.json: adds DD_TRACE_OPENFEATURE_ENABLED and aliases
• feature-flagging-{lib,bootstrap,agent} builds: drop unused dependencies (Moshi, JCTools, dd-trace-core, JMH…) and coverage exclusions
• Smoke tests build / app: use the :dd-openfeature jar and com.datadog.openfeature.Provider
• Lockfiles

Deleted files (81 files, moved to the SDK)

Deleted	Now in
feature-flagging-api module (Provider, DDEvaluator, hooks, metrics, benchmark, tests, README, build)	com.datadog.openfeature.* (#12843)
feature-flagging-config module	Keys in dd-trace-api FeatureFlaggingConfig, resolution in InstrumenterConfig (#12845)
api SpanEnrichmentGate	SDK Settings (#12841)
bootstrap ufc/v1/* + ParsedSemverTest	SDK internal/ufc (#12840)
bootstrap exposure/*, flagevaluation/*	SDK internal/exposure, internal/flagevaluation (#12842)
bootstrap SpanEnrichmentEvent + test	Backend.enrichSerialId / enrichRuntimeDefault and the SDK SpanEnricher SPI
lib UniversalFlagConfigParser, JsonApiUfcResponseParser + tests	SDK internal/ufc/UniversalFlagConfigParser (#12840)
lib AgentlessConfigurationSource, AgentlessFeatureFlagBackendApi, ConfigurationSourceService + tests	SDK internal/delivery (#12841)
lib FeatureFlagEvpPublisher, FeatureFlagBackendApiFactory, FeatureFlagEvpContext + tests	SDK FallbackTransport, DirectIntakeTransport (#12841); agent proxy part is now EventProxy
lib exposure writer / caches, flag evaluation writer / aggregator / payloads + tests	SDK pipelines (#12842)
lib JMH benchmarks, remote-config/*.json fixtures	dd-openfeature (#12842, #12840)

Stack

The full change is in #12709. It was split into this stack to ease the review.

1. Resolve Feature Flags enablement from instrumenter config #12845
2. Add dd-openfeature SDK flag configuration and evaluation core #12840
3. Add dd-openfeature SDK settings and configuration delivery #12841
4. Add dd-openfeature SDK exposure and flag evaluation pipelines #12842
5. Add dd-openfeature SDK OpenFeature provider #12843
6. Connect the dd-openfeature SDK to the agent #12844 👈 this PR
7. Add agentless and standalone OpenFeature smoke tests #12846

Jira ticket: APMLP-1512

🤖 Generated with Claude Code

[dd-octo-sts]

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	13.94 s	14.02 s	[-1.3%; +0.3%] (no difference)
startup:insecure-bank:tracing:Agent	12.89 s	12.97 s	[-1.4%; +0.2%] (no difference)
startup:petclinic:appsec:Agent	17.08 s	17.05 s	[-0.9%; +1.2%] (no difference)
startup:petclinic:iast:Agent	16.18 s	16.94 s	[-8.7%; -0.3%] (maybe better)
startup:petclinic:profiling:Agent	16.58 s	16.74 s	[-2.0%; +0.1%] (no difference)
startup:petclinic:sca:Agent	16.95 s	16.97 s	[-1.2%; +0.9%] (no difference)
startup:petclinic:tracing:Agent	16.16 s	16.03 s	[-0.3%; +1.9%] (no difference)

Commit: bfba4592 · CI Pipeline · Benchmarking Platform UI

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Load and DaCapo benchmarks can be triggered manually in the GitLab pipeline. Results will appear in the Benchmarking Platform UI after completion.