feat(cli): default release mode to event

[ablaszkiewicz]

Related PRs

Event mode is live today, and it is opt-in. These PRs settle where it stays and where it goes.

Deprecating the mobile knobs. The symbol id on these paths is already a content hash, so two releases collide only when they ship a byte-identical artifact. An ordinary release that changes code gets its own symbol set and never collides. The dSYM path also lost release attribution for embedded targets, because one upload covers every target while it creates one release. Review asked for deprecation instead of removal, so every knob stays accepted as a warned no-op.

• chore(cli): deprecate event release mode on the mobile uploads #92401 (merged, released in posthog-cli 0.17.0)
• chore(gradle-plugin): deprecate event release mode posthog-android#747
• chore: deprecate POSTHOG_NO_RELEASE_BIND in the dsym upload posthog-ios#791

Making it the default.

• feat(cli): default release mode to event #91823 ← this PR
• feat(plugins): default release mode to event posthog-js#4705

React Native. Scopes the mode to the Hermes upload and defaults it to event. That is the one path where two releases really do ship the same artifact.

• feat(react-native): scope event release mode to the Hermes upload posthog-js#4717

Problem

• Two releases that ship the same code report their exceptions on one release.
• The release that uploads the symbol set first takes them.

Changes

• --release-mode defaults to event on six commands.
• The commands are sourcemap inject, sourcemap process, sourcemap upload, hermes inject, hermes clone and hermes upload.
• --release-mode symbol-set keeps the old behavior. So does POSTHOG_RELEASE_MODE=symbol-set.
• proguard upload is out of scope here. The base PR deprecates its release mode, so its mapping always binds.
• hermes upload resolves --info-plist before it checks the release coordinates, so an iOS build that supplies them that way no longer gets a false warning.
• The shared event_coordinates_complete check requires name, version and build, because the server packs the build into the version it keys a release on.
• The help text no longer calls event experimental.

How did you test this code?

• Two tests pin the new default and two cover the symbol-set opt-out, across hermes inject, hermes clone and hermes upload.
• event_mode_needs_every_release_coordinate covers the shared predicate.
• Not run: an upload against a real project.

Automatic notifications

• Publish to changelog?

The sampo changeset is cli/.sampo/changesets/release-mode-event-default.md. It asks for a minor bump.

Docs update

The posthog.com docs still call symbol-set the default. They need a separate PR.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Written with Claude Code (Opus 5); restacked and narrowed with Claude Code (Fable 5). Skills invoked: /writing-pr-descriptions, /stacking-prs.

The base PR of the former stack is merged and released, and this branch is rebased onto master, so the diff shows only this layer. proguard upload --release-mode stays a hidden no-op there, so no commit in history defaults proguard to event.

[trunk-io]

😎 Stack merged successfully - details.

[github-actions]

🤖 CI report

✅ Trunk lane — non-backend lane

This PR is assigned to the non-backend lane. It does not run backend Python tests and may merge in parallel with PRs in other lanes.

[posthog]

🦔 PostHog Review reviewed this pull request

Found 2 must fix, 4 should fix, 1 consider.

Published 7 findings (view the review).

[posthog]

PostHog Review alpha 🦔 If you find any issues helpful - please reply "valid", "invalid", etc., for evaluation purposes 🙏

[posthog]

PostHog Review

Found 2 must fix, 4 should fix, 1 consider.

[greptile-apps]

Prompt To Fix All With AI

### Issue 1
cli/src/sourcemaps/plain/upload.rs:74
**Standalone uploads lose releases**

When an existing workflow runs `sourcemap upload` without first applying event-mode injection, the new default uploads release-independent symbol sets without adding or validating `_posthogReleaseId`, causing symbolicated exceptions to lose their release attribution.

### Issue 2
cli/src/sourcemaps/args.rs:98-101
**Release-mode documentation remains stale**

The CLI now defaults these commands to `event`, but the published documentation still describes `symbol-set` as the default, directing users toward behavior that no longer matches the CLI and omitting the coordinates event mode requires.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "fix(cli): correct the event mode release..." | Re-trigger Greptile}

[Copilot]

Pull request overview

This PR updates the PostHog CLI’s error-tracking upload/inject flows to make --release-mode=event the default, so identical artifacts across releases no longer collide on the first uploader’s release attribution and instead resolve release per event.

Changes:

• Default --release-mode to event across sourcemap inject/process/upload, Hermes clone/upload (and Hermes inject via shared args), and proguard upload.
• Update CLI help text and warnings to reflect event mode semantics and the symbol-set opt-out.
• Add a shared “event mode needs full coordinates” predicate plus tests, and record the behavior change in a Sampo changeset.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
cli/src/sourcemaps/plain/upload.rs	Switch default to event for plain sourcemap upload and update help text accordingly.
cli/src/sourcemaps/plain/mod.rs	Switch default to event for sourcemap process args and update help text.
cli/src/sourcemaps/inject.rs	Switch default to event for sourcemap inject and expand help text to cover web vs Hermes behavior.
cli/src/sourcemaps/hermes/upload.rs	Switch default to event, resolve Info.plist before validation, and use shared coordinate-completeness check.
cli/src/sourcemaps/hermes/mod.rs	Update tests to pin the new default and cover symbol-set opt-out, including hermes inject.
cli/src/sourcemaps/hermes/clone.rs	Switch default to event and update help text.
cli/src/sourcemaps/args.rs	Update ReleaseMode docs, refine conflict flag help text, add event_coordinates_complete, and add tests.
cli/src/proguard/upload.rs	Switch default to event, update warnings, and update tests for the new default and opt-out.
cli/.sampo/changesets/release-mode-event-default.md	Add release note for the default change and the updated warning behavior.

Suppressed comments (2)

cli/src/proguard/upload.rs:76

• This warning says event-mode release resolution uses the app's "namespace and version", but the check requires a build number too (event_coordinates_complete). Mentioning build here makes the warning consistent with the required coordinates and reduces confusion.

    if *release_mode == ReleaseMode::Event && !resolved_release.event_coordinates_complete() {
        warn!(
            "--release-mode=event resolves each exception's release from the app's namespace and \
             version. Pass --release-name, --release-version and --build matching the app's \
             applicationId, versionName and versionCode, or exceptions will report no release."

cli/src/sourcemaps/hermes/upload.rs:76

• This warning says event-mode release resolution uses the app's "namespace and version", but the check requires a build number too (event_coordinates_complete). Mentioning build here makes the warning consistent with the required coordinates and reduces confusion.

    if *release_mode == ReleaseMode::Event && !release.event_coordinates_complete() {
        warn!(
            "--release-mode=event resolves each exception's release from the app's namespace and \
             version. Pass --release-name, --release-version and --build matching the app's bundle \
             identifier or applicationId, its version and its build number, or exceptions will \

---

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[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-09-02 14:31 UTC	Run
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