https://2s.io/api/predict/matched-pairs
Cross-venue equivalent-market pairs for arbitrage / relative-value spotting. We fuzzy-match open Polymarket vs Kalshi markets by title-token overlap and return candidate pairs with both venues' YES prices and the implied-probability spread (Polymarket YES minus Kalshi YES). Tune with minScore (0-1 title-similarity floor) and limit. Heuristic — a high score is a strong candidate, not a guaranteed identical contract. Read-only, keyless. No public source maps these directly; the pairing is derived by 2s.io.
Start with a quote-only recipe. Payment signing stays in your project.
const response = await fetch("https://2s.io/api/predict/matched-pairs", {
method: "GET",
});
console.log(response.status);
console.log(Object.fromEntries(response.headers));
console.log((await response.text()).slice(0, 1000));
// A valid 402 is a quote, not a completed paid call.This sends no payment. Inspect the 402 response before adding a wallet-enabled client.
- Live 402 quote confirmed
GET returned a protocol-valid 402 quote (402). No payment was made.
- Origin reachable
HEAD https://2s.io/ returned 200.
- Observed in cdp-bazaar
The registry record was observed and retained with provenance.
- Observed in 402-index
Discovered through bazaar.
- Registry record checked
Registry health: healthy.
EVIDENCE
Each record has an exact-route quote outcome. Unresolved templates and potentially mutating methods are labeled instead of being invoked without provider-specific test input. A quote is still separate from a settled paid call.