A macOS menu bar app for monitoring and controlling Ohme EV chargers. Live power, charge slots and full charge control from your Mac - plus optional BMW CarData integration that keeps Ohme's battery estimate accurate.
OhmeBar is an unofficial, community project. It is not affiliated with, endorsed by, or supported by Ohme Operations UK Ltd or BMW Group.
Works with any Ohme charger and any EV - no BMW required:
- Menu bar icon that reflects charger state at a glance: charging, plugged in, paused, finished, pending approval, unplugged
- Live power readings: kW, amps, volts, session energy and battery percent
- Tonight's charge slots with per-slot energy
- Pause / resume, Max Charge / Smart mode, and approve-charge controls
- Edit the charge target (percent and ready-by time) inline
- Set the car's state of charge manually so Ohme's target maths stays honest
- Polls every 30 seconds while open, every 2 minutes in the background
- Launch at login, error badge in the menu bar, no Dock icon
Optional extra for BMW and MINI drivers:
- Link a BMW CarData client once, and OhmeBar automatically pushes the car's real battery level into Ohme every time you plug in - restoring the accurate target-based charging that disappeared when BMW cut off third-party API access
Ohme used to read the battery level of many cars (BMW included) through the car makers' unofficial mobile-app APIs. In late 2025 BMW blocked all third-party access to those APIs and Ohme silently dropped BMW from its supported brands, so the Ohme app now relies on a state of charge you typed in at plug-in time, extrapolated as the charge progresses. If that starting figure is stale, your "charge to 80%" target quietly becomes wrong.
BMW's official replacement is BMW CarData, a customer-facing API available in the EU and UK. OhmeBar speaks CarData directly: at plug-in it fetches the car's true state of charge and writes it into your Ohme account, so the Ohme app (and OhmeBar) compute the charge from reality. No Home Assistant, no cloud middleman - the Mac talks to BMW and Ohme directly.
- macOS 13 Ventura or later (Apple Silicon build provided; Intel users can build from source)
- An Ohme account with email/password login. If you signed up with Google or Apple, do a password reset on the Ohme account first - the API only supports email/password (same limitation as the Home Assistant integration).
- For the BMW extra: a BMW or MINI with ConnectedDrive, registered to a BMW ID in the EU or UK, and access to the BMW CarData portal. The BMW ID must be the vehicle's primary driver.
Grab the notarized build from Releases, unzip, drag
OhmeBar.app to Applications and launch. The bolt icon appears in the menu
bar; there is no Dock icon or main window.
brew install xcodegen
git clone https://github.com/beaglemoo/ohmebar.git
cd ohmebar
xcodegen generate
xcodebuild -scheme OhmeBar -configuration Release buildOr ./build.sh for a standalone ad-hoc-signed bundle in build/OhmeBar.app.
Run the tests with xcodebuild -scheme OhmeBar test.
Click the bolt icon and enter your Ohme account email and password. The password goes into the macOS Keychain, nowhere else. Charger status appears within a few seconds. Right-click the icon for Refresh, Launch at Login, Sign Out and Quit.
One-time setup, roughly five minutes:
- Sign in to the BMW CarData portal with the BMW ID that owns the car (the same login as the My BMW app). You can also reach it via your national BMW site -> My BMW -> select the car -> BMW CarData.
- Under "Technical access to BMW CarData", create a CarData client.
- Turn ON "Request access to CarData API". Wait a minute.
- Turn ON "CarData Stream". Wait another minute. (OhmeBar never uses the stream, but BMW's consent check wants both subscriptions enabled.)
- Copy the client ID.
- In OhmeBar's popover, click "Link BMW CarData", paste the client ID and click Link.
- OhmeBar shows a short pairing code and opens the BMW approval page. Make sure the code on the page matches the one in the popover (clear the field and re-enter it if not), then approve. Codes expire after 5 minutes.
- The popover flips to "BMW linked" and does its first sync immediately.
From then on, every time the car is plugged in, OhmeBar fetches the real state of charge from BMW and pushes it into Ohme before the smart charge is calculated. A "Sync from BMW" button is also available any time.
These are real failure modes we hit while building this, with fixes:
"access_denied" immediately after you approve, every time. The CarData
client itself is defective - BMW sometimes issues client credentials that
never propagate to its auth servers. The token endpoint briefly returns an
internal 500 (keymanagement.service.invalid_access_token) when you
approve, and the request is then recorded as "user declined". No amount of
retrying fixes that client. Solution: in the CarData portal, Delete Client,
create a new one, re-enable BOTH toggles (a minute apart), wait a few more
minutes, then link with the new client ID. This fixes it for almost
everyone.
The approval page shows a different code than OhmeBar. BMW's approval page caches the last code it saw. Approving a stale code silently kills the current pairing attempt. OhmeBar passes the code in the URL to defeat this, but if the field still differs, clear it and type the code from the popover. The code is case-sensitive.
The approval page says "Link your BMW ID to your car - please continue in the vehicle". Despite appearances this is also the device-approval page; the wording is shared with BMW's in-car login flow. As long as the code matched, the approval registered. If pairing still fails afterwards, see the defective-client fix above.
Quota. BMW allows 50 CarData API calls per day per account. A sync costs one call (two on the very first, to discover the VIN, and one extra whenever the descriptor container needs recreating). OhmeBar only syncs at plug-in and on demand, so normal use is a handful of calls a day. If you hit 429 errors, you have exhausted the day's quota.
Approving from the wrong BMW account. The approval must come from the same BMW ID that owns the CarData client, and that BMW ID must be the car's primary driver. Approvals from any other account are denied.
- Ohme: authenticates against Ohme's Firebase identity project with
your email/password, then calls
api.ohme.io- the same unofficial API used by the Home Assistant Ohme integration and ohmepy. Endpoints: charge sessions, next session rule, account/device info, pause/resume/approve, max-charge, charge-rule PATCH, state-of-charge PUT. - BMW: OAuth 2.0 Device Code flow with PKCE against BMW's GCDM identity
service, then the official CarData REST API (
api-cardata.bmwgroup.com). OhmeBar registers a small "descriptor container" for the two battery descriptors and pollstelematicDatawith it. Reference implementations: bmw-cardata-ha. - Tokens auto-refresh (Ohme ~45 min, BMW per expiry). All secrets live in the macOS Keychain.
- Credentials are stored only in the macOS Keychain on your Mac.
- OhmeBar talks exclusively to Ohme (
api.ohme.io), Google Identity (Ohme's login provider) and BMW (customer.bmwgroup.com,api-cardata.bmwgroup.com). No telemetry, no analytics, no third-party servers. - The Firebase API key in the source is Ohme's public web client key, shipped in their own apps - it is not a secret.
- The Ohme API is unofficial and can change without notice. If something breaks, check ohmepy and the Home Assistant integration for the current endpoint shapes.
- BMW CarData is EU/UK only and the readings are as fresh as the car's last report to BMW (typically at ignition-off and charging events).
- Price cap, solar mode and multi-vehicle selection are not exposed yet - see the roadmap.
- Charge history with charts
- Price cap and solar mode toggles for chargers that support them
- Multi-vehicle selection
- Sparkle auto-updates and a Homebrew cask
- dan-r for ohmepy and the Home Assistant Ohme integration, which document the Ohme API
- kvanbiesen and JjyKsi for the BMW CarData Home Assistant integrations, which document the CarData device flow
MIT - see LICENSE.