## What kind of change does this PR introduce?
Feature
## What is the current behavior?
The dev toolbar is only discoverable via `window.devToolbar()` in the
browser console, or by having your email on the `devToolbarDefaultOn`
ConfigCat flag. Once enabled, Studio shows a floating trigger button.
## What is the new behavior?
In local and staging Studio, the account/settings dropdown (avatar menu)
includes a **Local tools** section above **Theme** with a **Dev
toolbar** checkbox toggle.
- **On**: shows the floating orb (persists via localStorage, same as
`window.devToolbar()`)
- **Off**: hides the orb and dismisses the toolbar
Open the panel itself via the orb once it is visible. Production builds
are unchanged (`isAvailable` is false and the menu item is hidden).
| After |
| --- |
| <img width="226" height="204" alt="CleanShot 2026-08-20 at 12 46
38@2x"
src="https://github.com/user-attachments/assets/c846b119-626d-48f5-9a02-aef4d006326c"
/> |
| <img width="558" height="1024" alt="CleanShot 2026-08-20 at 12 47
04@2x"
src="https://github.com/user-attachments/assets/4b3dd22b-537b-4874-821d-c202033c4ad7"
/> |
## Manual testing
Run `pnpm dev:studio` and open http://localhost:8082.
1. **Find the entry point:** top-right avatar/settings menu → **Local
tools** → **Dev toolbar** (above **Theme**). Should not appear in
production builds.
2. **Turn it on:** check **Dev toolbar**. A green floating orb should
appear (default bottom-right).
3. **Open the panel:** click the orb. The **Dev Toolbar** sheet should
open with Events and Flags tabs.
4. **Event count:** navigate around Studio (e.g. open a project, switch
pages). The orb badge should increment and stay readable in light and
dark mode.
5. **Turn it off:** reopen the avatar menu and uncheck **Dev toolbar**.
The orb and panel should disappear.
6. **Close vs hide:** with the toolbar on, open the sheet and use
**Close** (X). The orb should remain; only the sheet closes.
Optional: confirm `window.devToolbar()` in the browser console still
enables the orb.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added a Local tools option to enable the development toolbar when
available.
* Toolbar activation and dismissal preferences now persist between
sessions.
* Added clearer event-count badges with responsive sizing for larger
counts.
* **Improvements**
* Simplified toolbar controls by removing the separate hide option.
* Improved toolbar availability handling across local and production
environments.
* **Tests**
* Expanded coverage for activation, persistence, visibility, and
event-count badges.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Danny White <dnywh@users.noreply.github.com>
Co-authored-by: Sean Oliver <882952+seanoliver@users.noreply.github.com>
## Problem
We need a local-only UI to inspect client and server telemetry events
and override flags during development without touching non-local env
behavior. This work is intended to be shared across Studio, Docs, and
WWW.
## Changes
- Introduced a shared `dev-tools` package with the Dev Telemetry Toolbar
UI, trigger, and provider.
- Wired the toolbar into Studio, Docs, and WWW app shells (local-only
gating).
- Added a local-only `devTelemetry()` opt-in with storage gating and SSE
subscription.
- Wired client PostHog events into a local listener and re-exported
types.
- Added local flag override cookie support in the UI and CODEOWNERS for
the new package.
- Added unit tests covering local/non-local behavior and flag utilities.
## Testing
Manual (local only):
- Start each app locally: `pnpm dev:studio`, `pnpm dev:docs`, `pnpm
dev:www`
- Open the app, run `devTelemetry()` in the browser console
- Click around and confirm both client and server events appear (client
will be page views only)
- Verify feature flag overrides (PostHog + ConfigCat) persist and
restore correctly
- Confirm dismissing the toolbar clears local storage and hides the
trigger
Unblocked by https://github.com/supabase/platform/pull/29172
Resolves GROWTH-591
Demo:
[github.com/user-attachments/assets/60b376db-7440-4ada-82f5-d1bd4af4db3b](https://github.com/user-attachments/assets/60b376db-7440-4ada-82f5-d1bd4af4db3b)
Screenshots:
<img width="1368" height="972" alt="1"
src="https://github.com/user-attachments/assets/d2f20a0c-191f-4118-bb5e-15b25f5a54a9"
/>
<img width="1423" height="790" alt="2"
src="https://github.com/user-attachments/assets/115598e2-7287-49bf-9ed7-71ecc679dee3"
/>
<img width="1433" height="882" alt="3"
src="https://github.com/user-attachments/assets/51f666f2-9efc-410f-baec-378bdee9dbfe"
/>
<img width="608" height="483" alt="4"
src="https://github.com/user-attachments/assets/584d6cf5-1b2f-4cee-9e6a-d55ce2e3bae5"
/>
<img width="628" height="305" alt="5"
src="https://github.com/user-attachments/assets/991a9b39-578a-4565-b110-537a02040a53"
/>
<img width="659" height="447" alt="6"
src="https://github.com/user-attachments/assets/95ef405c-fffa-44af-bf6a-f974b780e3fc"
/>
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Developer Toolbar (local only): view client/server telemetry, inspect
events, and manage/override feature flags with persistent overrides,
filtering, and clear/reload.
* Client-side telemetry hooks: surface structured events to dev tooling
for realtime inspection.
* **Bug Fixes**
* Fixed end-of-file newline in shared code.
* **Chores**
* Added dev-tools package, integrated provider and trigger across
Studio, Docs, and marketing sites, and added CODEOWNERS entry.
* **Tests**
* Added comprehensive tests and test setup for the DevToolbar.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Charis Lam <26616127+charislam@users.noreply.github.com>
Danny White