Polymarket Reference
WS·polymarket_reference·Dev Tier+·
Live Chainlink USD prices for the crypto assets behind Polymarket's up/down markets, including BTC, ETH, SOL, XRP, DOGE, BNB and HYPE. These are the prices those markets settle on, separate from YES contract prices.
Overview
Use case: Compare the live Chainlink price with a Polymarket up/down window's price to beat while tracking contract quotes on prices.
Requirements
- Uses your existing prices entitlement on Dev, Pro, and Enterprise. Subscribe once with no market_ids, group_ids, or event_ids. Each update identifies its index_id (for example btc/usd); filter locally for the symbols you need.
- Each symbol updates about once per second. This is an event-driven feed, not a fixed timer; do not interpolate missing values or assume every second produces a value.
- Wait for POLYMARKET_STREAM_READY, then use the next index_value. POLYMARKET_STREAM_INTERRUPTED means the previous value is stale. Updates are live only; there is no initial snapshot or replay.
- The value is a decimal string in USD, not a contract probability. source_ts_ms is the Chainlink timestamp; the outer ts is Prediction.com delivery time. Compare source timestamps to reject older values.
- A slow consumer is disconnected with code 1013. Reconnect and resubscribe, then wait for a fresh value. Unsubscribe with no IDs to stop the feed.
Send
| Field | Type | Required | Notes |
|---|---|---|---|
| action | string | yes | Must be "subscribe" for this section. |
| channel | string | yes | Must be "polymarket_reference". |
| market_ids | string[] | unsupported | Do not send. Filter index_id in received messages. |
| group_ids | number[] | unsupported | Do not send. |
| event_ids | number[] | unsupported | Do not send. |
| wildcard | behavior | fixed | No IDs: receive all available reference index values. |
Receive
Data messages use the standard envelope: channel, type, ts, data. Types for this channel include: index_value.
Subscribe with {"action":"subscribe","channel":"polymarket_reference"}. For a Polymarket Bitcoin up/down window, filter to index_id=btc/usd and compare it with the window's price to beat: the window resolves Up when the Chainlink price at its end is at or above the price at its start. Kalshi's equivalent windows settle on CF Benchmarks' BRTI on kalshi_reference, so the two can resolve differently when the price barely moves.
Data fields (inside data)
| Field | Type | Description |
|---|---|---|
| type | string | index_value |
| index_id | string | Lowercase symbol pair, for example btc/usd, eth/usd, sol/usd, or xrp/usd. |
| value_usd | string | Current Chainlink price in USD as a decimal string. |
| source_ts_ms | integer | Chainlink price timestamp in Unix milliseconds. |
| source | string | chainlink |