GitHub - frenchie4111/midterms-watcher: macOS menu bar app: Polymarket odds + live AP vote counts for the 2026 US midterms

A small macOS menu bar app for watching the 2026 US midterms on election night. It puts Polymarket odds next to live AP vote counts in one panel.

Menu bar: House and Senate control odds at a glance (🏛 H D95 S D76)
Header: chamber control odds with 24h change, live seats won vs. seats needed, and balance-of-power scenarios
Race list: every Senate, Governor and House race on Polymarket, sorted by volume, with candidate photos, odds bars and "% in" vote counts once counting starts
Race detail: all outcomes, today's odds chart, the AP vote count with % of expected vote, and a vote-share-over-time chart
Notifications: 5-point odds swings, a new favorite, and AP race calls
Refreshes every 60 seconds. Single Swift file with no dependencies, universal binary (Apple Silicon and Intel).

Install

Requires macOS 14 (Sonoma) or later.

Option 1: download. Grab MidtermsWatcher.dmg, open it, and drag Midterms Watcher into Applications. Launch it from Applications or Spotlight. It's signed and notarized, so it opens without Gatekeeper warnings.

Option 2: one-line install.

curl -fsSL https://raw.githubusercontent.com/frenchie4111/midterms-watcher/main/install.sh | bash

This downloads the latest release into /Applications and launches it.

Option 3: build from source (needs Xcode Command Line Tools: xcode-select --install):

git clone https://github.com/frenchie4111/midterms-watcher.git
cd midterms-watcher
./install.sh --from-source

After launching, look for the 🏛 in your menu bar and allow notifications when asked. Click Open at login in the panel footer to start it automatically.

Uninstall: quit it from the ⏻ button, then delete the app. Or run curl -fsSL https://raw.githubusercontent.com/frenchie4111/midterms-watcher/main/install.sh | bash -s -- --uninstall.

Data sources

What	Source
Odds, 24h change, volume	Polymarket Gamma API (events tagged `midterms`)
Today's odds chart	Polymarket CLOB `prices-history`
Vote counts, % expected vote, race calls, seat tallies	AP results via the New York Times' public results JSON

Neither source publishes a vote-count history. The app records a snapshot each time a race's count changes, to ~/Library/Application Support/MidtermsWatcher/. The vote-share chart only covers the time the app has been running, so leave it open.

Polymarket races are matched to results by state for Senate and Governor races. House district races show odds only.

Development

./build.sh                                   # ad-hoc signed build in build/
"build/Midterms Watcher.app/Contents/MacOS/MidtermsWatcher" --window   # panel in a regular window

Debug environment variables:

MIDTERMS_RESULTS_DATE=2024-11-05 exercises the vote UI against 2024's results.
MIDTERMS_SELECT=<polymarket-event-slug> preselects a race.

Releasing: bump CFBundleShortVersionString in Info.plist, then run ./release.sh. It builds, signs with Developer ID, and notarizes. Notarization needs APPLE_ID, APPLE_APP_SPECIFIC_PASSWORD and APPLE_TEAM_ID in the environment, or a keychain profile from ./release.sh --setup-notary. Then run the gh release create command it prints.

License

MIT. Not affiliated with Polymarket, the AP or the New York Times. Odds are not predictions or advice.