Dome API Alternative — the Mapping Layer for Prediction Markets
Dome announced in February 2026 that Polymarket is acquiring it. If that news puts your stack back on the table, the part worth re-deciding is identity: one mapped event ID per game across Polymarket International, Polymarket US, Kalshi and PredictFun, with every venue's own market ID kept native beside it.
Short answer
Dome sells market data: live trades, historical order books and prices, websockets and webhooks, behind one SDK. matchwire sells mapping: one row per game, the same-event ID that joins a Polymarket listing to a Kalshi listing to a PredictFun listing, mapping only, no prices and no order books.
They are different layers, so most teams run both — Dome (or the venue APIs, or pmxt) for the data, matchwire for the join. If you want one vendor for data and trading as well as mapping, pmxt covers more venues and adds prices, history and hosted trading; this page is about the layer Dome never covered.
matchwire vs Dome, by scope
| Point | matchwire | Dome |
|---|---|---|
| What it is | Mapping layer, hosted | Unified market-data API and SDK (domeapi.io) |
| Event identity | One mapped row per game: ev:SPORT:TEAM-A:TEAM-B:YYYY-MM-DD, venue IDs kept native |
Markets and trades per venue through the SDK; no cross-venue event ID to key your data on |
| Carries | Mapping only: no prices, no order books — read the venue with the listing's ready-made request | Granular market data: live trades, historical order books and pricing, webhooks and websockets |
| Venues | Four: Polymarket International, Polymarket US, Kalshi, PredictFun | Polymarket, Kalshi and more, as listed on domeapi.io |
| Market types | Winners, spreads, totals and props matched, line included: over 45.5 is never matched to over 48.5 | Whatever each venue lists, reached through the SDK's own market objects |
| Upkeep | Alias lists maintained for you; the mapped ID keeps working when a venue renames a game | Yours: your code owns the reconciliation when two venues title the same game differently |
| Pricing model | Flat monthly from $99 (unlimited real-time stream, 14-day trial on Starter) | Not published on domeapi.io — free sign-up is advertised; ask them for terms |
| Ownership | Independent of every venue it maps | Being acquired by Polymarket, one of the venues it serves (Dome's own announcement, February 2026) |
Migration is additive, not a rewrite
You do not have to move off Dome to use matchwire. Add the mapped ID beside the IDs you already hold, and keep every existing call.
# your Dome call, unchanged
GET https://api.domeapi.io/v1/polymarket/market-price/...
# add identity from matchwire, once
GET https://api.matchwire.win/api/v1/rows?sport=nfl key: YOUR_KEY
# the row you key on gains a mapped id; venue ids stay native
"id": "ev:nfl:cleveland-browns:pittsburgh-steelers:2026-10-02"
"listings": [ { "venue": "kalshi", "marketId": "KXNFLGAME-26OCT02PITCLE", "request": {...} } ]Three steps
- Swap the key — or add one; the quickstart's first key is one call.
- Swap the ID you key your own data on to the mapped row ID.
- Verify the mapped events against the games you already track.
What stays the same
Your venue calls, your Dome calls, and the market IDs you already store all keep working. The mapped ID is attached alongside, so nothing you hold becomes invalid.
FAQ
- Do I have to drop Dome?
- No. Dome is the data layer; matchwire is the identity layer. Teams run both, and the news about the acquisition does not force a change on your side.
- What does matchwire replace?
- The reconciliation job: the aliases, the "is this the same game" logic, and the line matching. It does not replace prices, order books or history — read those from the venue using each listing's ready-made request.
- Do mapped IDs replace venue IDs?
- No. They are attached alongside, formatted
ev:<sport>:<team-a>:<team-b>:<YYYY-MM-DD>. - How is matchwire priced?
- Flat monthly from $99 for the Starter plan, unlimited real-time stream, 14-day free trial. Personal plans; a commercial licence is needed if you serve others. All plans.
- What about pmxt as the alternative?
- pmxt covers more venues and adds prices, history, an SDK and hosted trading. The full table is on pmxt vs matchwire.
- Trial path?
- Start at the quickstart.