# Crosswire — Polymarket & Kalshi Arbitrage (remote · api.crosswire-api.com)

Cross-venue Polymarket+Kalshi arbitrage: resolution mismatch, void risk & settlement divergence.

- Trust score: 61/100 (medium)
- Change this week: +5
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-08-03

## Components

- remote · `api.crosswire-api.com`: 61/100 (this document), [markdown](https://verifymcp.io/servers/com-crosswire-api-crosswire-polymarket-kalshi-arbitrage/api.md), [page](https://verifymcp.io/servers/com-crosswire-api-crosswire-polymarket-kalshi-arbitrage/api)

## Channel facts

- Endpoint: `https://api.crosswire-api.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.6.2`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-08-03.

- **Endpoint Security**: 57/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 2 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS is enforced; there's no plaintext access path.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 46/100
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 953 tokens (~476/item across 2 items; 2 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 27/100
  - Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### Claude

```bash
claude mcp add --transport http com-crosswire-api-crosswire-polymarket-kalshi-ar https://api.crosswire-api.com/mcp
```

### Codex

```toml
[mcp_servers.com-crosswire-api-crosswire-polymarket-kalshi-ar]
url = "https://api.crosswire-api.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "com-crosswire-api-crosswire-polymarket-kalshi-ar": {
      "type": "remote",
      "url": "https://api.crosswire-api.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add com-crosswire-api-crosswire-polymarket-kalshi-ar --url https://api.crosswire-api.com/mcp --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  com-crosswire-api-crosswire-polymarket-kalshi-ar:
    url: "https://api.crosswire-api.com/mcp"
```

### Other

```json
{
  "mcpServers": {
    "com-crosswire-api-crosswire-polymarket-kalshi-ar": {
      "type": "http",
      "url": "https://api.crosswire-api.com/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-08-03 (score 61, +1)

No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-31 (score 60, +2)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-30 (score 58, 0)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-29 (score 58, +1)

No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-28 (score 57, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-27 (score 56, 0)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-26 (score 56)

First indexed and scored.

## MCP tools (2)

### `check_resolution_risk` (~612 tokens)

Pre-trade safety check for cross-venue event markets (crypto
oracle-divergence pairs, metered; World Cup football, free). Flags
resolution mismatches, void-rule divergence, scope differences
(e.g. 90-minute vs extra-time; matched vs differing strike),
settlement-source and -timing gaps, stale data, and thin liquidity
between the two Polymarket and Kalshi legs BEFORE you execute both.
Returns a machine-readable verdict — execution_verdict:
safe / caution / block — inside a full Fungibility & Settlement Audit Object
(FSAO) with structured findings, top-level divergence flags, venue
rule overrides, fee-adjusted spread, and verdict reasons. Identify the
pair by EITHER canonical_event_id (a live pair id from
list_covered_events — the metered 'crypto:' inventory rolls daily, so
fetch a current id there rather than reusing an old one; the free 'wc26:'
World Cup pairs are stable) OR market_a + market_b (one Polymarket
conditionId + one Kalshi ticker, order-insensitive). If the pair is not
covered, returns a non-error
coverage reply (covered: false) naming the covered inventories (free
World Cup football + metered crypto pairs) and the coverage cutoff
instead of an FSAO.

Input parameters:

- `api_key`: Crosswire API key (cw_…). Optional. Free for the World Cup graph and the first calls/day on metered crypto pairs; beyond that, metered crypto calls draw down this key's prepaid USDC balance (top up v…
- `canonical_event_id`: A covered pair id — the outcome-suffixed canonical id. Two namespaces: the metered crypto oracle-divergence inventory (shape 'crypto:btc-above:<date>:strike-<n>#above' — $0.02 USDC per call after 3 f…
- `market_a`: First leg of the pair to audit (either venue; order does not matter). Provide market_a AND market_b together, or use canonical_event_id instead.
- `market_b`: Second leg of the pair to audit (the other venue).
- `mode` (string): 'advisory' (default) or 'strict'.
- `notional_usd`: Intended position size in USD. Optional; sizes the thin-liquidity check against live top-of-book depth.

### `list_covered_events` (~163 tokens)

Free discovery of everything check_resolution_risk can audit across
both inventories — the free World Cup football pairs and the metered
crypto oracle-divergence pairs (the 'crypto:' namespace is the paid
surface: $0.02 USDC per call after 3 free calls/day). Returns the
covered canonical events, their per-outcome pair ids (…#home / #draw /
\#away for football), the Polymarket conditionIds and Kalshi tickers
with outcome labels for each pair, match dates, the frozen ruleset_sha
pinning the identity graph, the coverage kickoff cutoff, and snapshot
freshness. Use a returned pair_id (or a pair's two market ids) as input
to check_resolution_risk.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/com-crosswire-api-crosswire-polymarket-kalshi-arbitrage/api#diagnostics

## Score history

- 2026-08-03: 61
- 2026-08-02: 60
- 2026-08-01: 60
- 2026-07-31: 60
- 2026-07-30: 58
- 2026-07-29: 58
- 2026-07-28: 57
- 2026-07-27: 56
- 2026-07-26: 56

## Links

- Remote endpoint: https://api.crosswire-api.com/mcp
- Repository: https://github.com/NicolasDuarte04/crosswire-mcp
- Website: https://crosswire-api.com/
- Changelog RSS feed: https://verifymcp.io/servers/com-crosswire-api-crosswire-polymarket-kalshi-arbitrage/api/changelog.xml
- Changelog JSON feed: https://verifymcp.io/servers/com-crosswire-api-crosswire-polymarket-kalshi-arbitrage/api/changelog.json
- HTML version of this page: https://verifymcp.io/servers/com-crosswire-api-crosswire-polymarket-kalshi-arbitrage/api