Session replay: attach replay debug properties to events

[ioannisj]

Part of the replay parity tracker PostHog/posthog#30889.

Problem

When replay is active, posthog-js attaches replay debug properties ($recording_status, $sdk_debug_replay_*) to every captured analytics event, so you can tell from an event whether replay was recording. The Android SDK attaches none: buildProperties() in PostHog.kt adds session/window/SDK-info props but no $recording_status / $sdk_debug_*.

Scope

• Attach the replay debug properties to captured (non-snapshot) events while recording, matching the web SDK keys.

Reference: posthog-js packages/browser/src/posthog-core.ts:1558 (extend(properties, this.sessionRecording.sdkDebugProperties)), session-recording.ts, and the keys in constants.ts.

Parity across SDKs

• Android: Session replay: attach replay debug properties to events #640 (this issue)
• iOS: Session replay: attach replay debug properties to events posthog-ios#726
• React Native: Session replay: attach replay debug properties to events posthog-js#4185