Report Kotlin and Graal runtimes in worker heartbeats

[Quinn-With-Two-Ns]

What changed?

Report Kotlin and Graal runtimes in worker heartbeats — preserve JVM version reporting, add Graal native-image detection, and report Kotlin with its runtime version when a directly registered workflow or activity implementation has Kotlin metadata.

Why?

Report which language runtimes a worker uses alongside its existing JVM environment information. Detection is best effort any failure does not block registration or reporting. Kotlin detection is scoped per worker rather than based on classpath presence. Existing environment-info opt-out and retry-until-accepted behavior are preserved.

Server PR

API dependency: temporalio/api#880. No coordinated server PR is required by the SDK reporting changes; these use the existing worker-heartbeat environment runtime fields.

Validation

• ./gradlew --offline spotlessApply completed.
• All 11 WorkerEnvironmentInfoTest unit tests passed.
• All 67 temporal-kotlin tests passed, including six new registration-to-heartbeat tests.
• SDK WorkerHeartbeat* test invocation completed; 13 existing heartbeat tests were skipped by the default in-memory server configuration.
• git diff --check passed.

---

Note

Low Risk
Telemetry-only additions to worker heartbeats with best-effort detection and existing opt-out; no changes to task execution or public API signatures.

Overview
Worker heartbeats can now include Graal native-image and Kotlin runtimes in the one-shot environment payload, in addition to the existing JVM version.

Graal is detected at client/worker environment probe time via Graal system properties (org.graalvm.nativeimage.imagecode / org.graalvm.version). Kotlin is added per worker when a directly registered workflow or activity implementation class carries kotlin.Metadata; the Kotlin version is resolved reflectively from that class’s loader. Detection is best effort—probe failures are isolated so hosting/platform reporting still works—and setDisableWorkerEnvironmentInfo still suppresses all of this. Kotlin reporting is per worker (not classpath-wide), and the retry-until-accepted / clear-after-accept heartbeat behavior is unchanged.

Docs and changelog are updated; unit and temporal-kotlin integration tests cover Graal properties, Kotlin augmentation, opt-out, and registration paths.

^{Reviewed by Cursor Bugbot for commit b4ca68f. Bugbot is set up for automated code reviews on this repo. Configure here.}

[Sushisource]

Do we have any tests that run under graal/kotin that could be integ tests for verifying the detection?

Not a huge deal either way