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Pre-trade resolution audit · Cross-venue event markets

The same match is not the same bet.

One venue settles a cancelled match to “No”; the other resolves it to a fair price. One market ends at 90 minutes; another includes extra time. Crosswire is a pre-trade resolution audit for cross-venue event markets: before your agent fires both legs of a hedge, it asks us whether the two contracts actually settle the same way. It gets the exact divergence that would break the trade. SAFE, CAUTION, or BLOCK.

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operator · zsh
$ curl -s https://api.crosswire-api.com/v1/audit \ -H "X-API-Key: $CROSSWIRE_KEY" -H "Content-Type: application/json" \ -d '{"canonical_event_id": "wc26:match:MEX-RSA:2026-06-11:result#home"}' \ | jq '{execution_verdict, findings: [.findings[].code]}' { "execution_verdict": "block", "findings": ["void_rule", "settlement_source", "settlement_timing"] }
What the gate checks

Three ways the “same” market breaks.

Cross-venue price gaps survive because the two legs are not actually the same bet. The audit names the divergence before it costs you the hedge.

01 · Scope

Where does the match end?

A market that pays on the 90-minute result is not a hedge for one that includes extra time and penalties. A draw at 90 that is decided on penalties settles the two legs inconsistently. The spread between them was never capturable.

02 · Void rules

What happens to a cancelled match?

On the matches we cover today, Polymarket resolves a cancelled match to “No” while Kalshi resolves the same cancellation to a fair price. One leg voids while the other settles. This divergence is live on every covered pair. It is the launch finding. The gate blocks on it.

03 · Settlement source & timing

Who declares the result, and when?

fifa.com statistics adjudicated by UMA on one venue; internal settlement with no external source cited on the other, and no stated timing. Contested or late-corrected results can settle differently, or hours apart.

One endpoint. An auditable answer.

Send the two market references; receive a Fungibility & Settlement Audit Object with the verdict and its reasons. Two real responses:

POST/v1/audit Request
request.json
{
  "canonical_event_id":
    "wc26:match:MEX-RSA:2026-06-11:result#home"
}

Authenticated with the X-API-Key header. The pair can also be named by its two venue market ids.

BLOCK Response · 200 · served from production
fsao.json · abridged
{
  "audit_id": "aud_01KTW12YWQ7981AXFX2SFE3JAE",
  "canonical_event_id": "wc26:match:MEX-RSA:2026-06-11:result#home",
  "leg_a": { "venue": "polymarket", "market_id": "0x4cd77d45…10ff" },
  "leg_b": { "venue": "kalshi", "market_id": "KXWCGAME-26JUN11MEXRSA-MEX" },
  "matching_confidence": 0.98,
  "semantically_fungible": false,
  "scope_divergence_flag": false,
  "void_rule_divergence_flag": true,
  "settlement_source_divergence_flag": true,
  "settlement_timing_divergence_flag": true,
  "findings": [
    { "code": "void_rule", "severity": "fatal",
      "detail": "Void conditions differ … A core void asymmetry
                 can void one leg while the other settles.",
      "affects_fungibility": true },
    { "code": "settlement_source", "severity": "warn",
      "detail": "fifa.com (UMA-adjudicated) vs Kalshi internal …" },
    { "code": "settlement_timing", "severity": "warn",
      "detail": "2h statistics fallback vs unspecified …" }
  ],
  "fee_adjusted_true_spread": -0.011,
  "execution_verdict": "block",
  "ruleset_sha": "af11f6c92521…b6029f"
}
Advisory · fail-open by default

The gate advises; it never trades. If Crosswire is unreachable, your bot proceeds exactly as it would without us, and the SDK marks the result degraded=true so you can alert on it. Strict mode (halt on uncertainty) is opt-in. During an outage in advisory mode a trap can slip through. That is the trade, and we state it rather than hide it.

Operating facts · measured, not promised
1.9 ms
server-side p50 per audit
4
matches covered today
12
contract pairs audited
af11f6c92521
frozen ruleset sha

p50 measured on the production serving path over 100 keyed requests, 2026-06-11. The request path is a cache read, not a live recompute, and we make no latency guarantees. Network time from your machine is yours. Every verdict is logged, append-only, and reproducible from {ruleset_sha, snapshot_ts, canonical_event_id}.

Covered now.

The identity graph is curated by hand: equivalence, void rules and resolution sources are read from the venues’ own rules text, then frozen and hashed. Coverage expands daily through the tournament; each freeze bumps the ruleset sha.

As of launch · 2026-06-11 ruleset af11f6c92521
Mexico vs South Africa2026-06-113 pairs · home / draw / away
Korea Republic vs Czechia2026-06-113 pairs · home / draw / away
Canada vs Bosnia-Herzegovina2026-06-123 pairs · home / draw / away
United States vs Paraguay2026-06-123 pairs · home / draw / away

Each match is three contract pairs (home, draw, away), matched across Polymarket and Kalshi at 0.98 confidence. Free endpoints (/v1/health, /v1/events, the MCP tools) are rate-limited at 10 requests per second per IP; /v1/audit requires a key.

For agents

Your agent can wire this in without you.

Crosswire speaks MCP. An agent that discovers the endpoint can list the covered events and run a pre-trade audit on its own. No human in the loop; no key needed for the MCP tools.

MCP · free, no key

  • check_resolution_risk: two market refs in, full FSAO out
  • list_covered_events: coverage, pair ids, ruleset sha
mcp.json
{
  "mcpServers": {
    "crosswire": {
      "url": "https://api.crosswire-api.com/mcp"
    }
  }
}

REST · keyed

Free opening-weekend keys are issued by mail while the program runs. Three lines to a verdict:

quickstart.sh
curl -s https://api.crosswire-api.com/v1/audit \
  -H "X-API-Key: $CROSSWIRE_KEY" -H "Content-Type: application/json" \
  -d '{"canonical_event_id": "wc26:match:USA-PAR:2026-06-12:result#home"}'

What we never do.

The boundary is the trust anchor. It is written into the spec and it does not move.