Show Polymarket or Kalshi Odds in the Mac Menu Bar

What you need

Multimeter for macOS 13 or later, $19.99 once.
The market’s slug (Polymarket: the last part of the market’s address) or ticker (Kalshi: shown on the market page).

Polymarket: add a Web Address meter with the slug in the address and the key path 0.outcomePrices. The reply holds the prices as text, like ["0.925", "0.075"]; Multimeter reads the first, the price of Yes.
Web address
```
https://gamma-api.polymarket.com/markets?slug=MARKET-SLUG
```
Kalshi: use the market address with the key path market.last_price_dollars.
Web address
```
https://api.elections.kalshi.com/trade-api/v2/markets/TICKER
```
Set the range to 0 to 1 so a Ring or Pie fills to the odds, and refresh every 5 minutes.

In Customize This Meter… (from the meter’s menu):

Settings for this meter
Setting	Value
Source	Web Address
Web address	one of the two above
Key path	`0.outcomePrices` (Polymarket) or `market.last_price_dollars` (Kalshi)
Refresh every	5 minutes
Range	0 to 1
Label	a short name for the question
Face	Pie, Ring or Sparkline

Tested: Run on October 29, 2026: a Polymarket House control market returned 0.925; Kalshi’s KXWARMING-50 returned 0.70.

More on this source, including every format it reads, in the Web Address guide.

What the meter says, why, and what to do
Symptom	Cause	Fix
No number found in the response	The key path doesn’t match the reply.	Run `curl -s` with the address and read the JSON. Dots walk into objects, numbers pick array items (`items.0.count`).
Couldn’t reach the address	No network, a typo in the host, or the service is down.	Open the address in your browser. Multimeter tries again at the next refresh.
No number found for Polymarket	The slug is an event with several markets, not a single market.	Open the specific outcome on polymarket.com and use the slug from that page.

Why does a Kalshi market show 0?

It has had no trades yet. Use market.yes_bid_dollars for the current bid instead.