# crosscheck (remote · crosscheckapi.com)

Checks for AI agents over x402: review drafts, accept-check handoffs, scan skills before install.

- Trust score: 57/100 (low)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-26

## Components

- remote · `crosscheckapi.com`: 57/100 (this document), [markdown](https://verifymcp.io/servers/com-crosscheckapi-crosscheck/crosscheckapi-2.md), [page](https://verifymcp.io/servers/com-crosscheckapi-crosscheck/crosscheckapi-2)
- npm · `crosscheckapi`: 72/100, [markdown](https://verifymcp.io/servers/com-crosscheckapi-crosscheck/crosscheckapi.md), [page](https://verifymcp.io/servers/com-crosscheckapi-crosscheck/crosscheckapi)

## Channel facts

- Endpoint: `https://crosscheckapi.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.5.4`

## 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 2026-09-26.

- **Endpoint Security**: 46/100
  - 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 6 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 enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
  - 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**: 64/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1301 tokens (~216/item across 6 items; 6 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 3/100
  - Stability observed for 1 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 99/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 96% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 6 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 7 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 60/100
  - Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28.

## Install

### How do I install the crosscheck MCP server?

crosscheck is a hosted endpoint at https://crosscheckapi.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http com-crosscheckapi-crosscheck 'https://crosscheckapi.com/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "com-crosscheckapi-crosscheck": {
      "url": "https://crosscheckapi.com/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "com-crosscheckapi-crosscheck": {
      "type": "http",
      "url": "https://crosscheckapi.com/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.com-crosscheckapi-crosscheck]
url = "https://crosscheckapi.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "com-crosscheckapi-crosscheck": {
      "type": "remote",
      "url": "https://crosscheckapi.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add com-crosscheckapi-crosscheck --url 'https://crosscheckapi.com/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  com-crosscheckapi-crosscheck:
    url: "https://crosscheckapi.com/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "com-crosscheckapi-crosscheck": {
      "Transport": "http",
      "Url": "https://crosscheckapi.com/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add com-crosscheckapi-crosscheck -t streamable-http -u 'https://crosscheckapi.com/mcp'
```

### Other

```json
{
  "mcpServers": {
    "com-crosscheckapi-crosscheck": {
      "type": "http",
      "url": "https://crosscheckapi.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.

### 2026-09-26 (score 57, 0)

- [functional regression] Schema quality: 194 → 216
- [functional improvement] Stability: unverified → 0.03
- [functional] New tool “verify_receipt”
- [cosmetic] “check” added an optional parameter “open_review”
- [cosmetic] “check” added an optional parameter “moltbook_identity”

### 2026-09-25 (score 57)

First indexed and scored.

## MCP tools (6)

### `check` (~297 tokens)

Review a draft

Independent review of a draft (email, report, summary, PR description) before its human sees it. Returns pass or specific issues with fixes; arithmetic is recomputed in code. With sources, each claim is checked against them and quotes are verified. $0.02. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.

Input parameters:

- `draft` (string, required): The draft text to review
- `moltbook_identity` (string): Optional: a Moltbook identity token for the free tier, when it is on (a verified Moltbook agent gets free checks with no payment). Not stored. Without a free check left, the price comes back as usual
- `open_review` (boolean): Optional: let a qualified outside reviewer take the job (not routed yet; crosscheck's reviewer does it and the receipt says so)
- `ref` (string): Optional: the hash of a crosscheck receipt that brought you here. Its wallet earns check credits from your first 90 days of spend.
- `sources` (array): Optional texts the draft relies on; turns on grounding

### `accept` (~269 tokens)

Check a deliverable against its task

Checks work another agent handed back against the task it was given, before you pay, release escrow, or pass it on. Returns accept, reject, or verify_externally with every requirement judged; counts, required JSON fields, and sums are checked in code. Optional payment_tx is verified on chain. $0.03 base. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.

Input parameters:

- `deliverable` (string, required): What came back
- `payment_network` (string): Network of payment_tx, for example eip155:8453
- `payment_tx` (string): Optional transaction hash of the payment for this work
- `ref` (string): Optional: the hash of a crosscheck receipt that brought you here. Its wallet earns check credits from your first 90 days of spend.
- `reference` (string): Optional reference material the task points to
- `task` (string, required): The task as given to the other agent

### `skillcheck` (~220 tokens)

Security review of a skill or MCP server

Security review of a skill or MCP server's files before you install or connect it: read, never run. Free when these exact files were scanned before (looked up by bundle hash); otherwise paid, $0.03 base. Never says safe. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.

Input parameters:

- `files` (array, required): Every text file of the skill or server, docs included; code rules read all of them
- `fresh` (boolean): Scan again even when a past scan of these exact files exists
- `ref` (string): Optional: the hash of a crosscheck receipt that brought you here. Its wallet earns check credits from your first 90 days of spend.

### `skillcheck_lookup` (~58 tokens)

Look up a past skillcheck

Free. The latest skillcheck of an exact bundle, by its bundle_sha256 (SHA-256 of the canonical JSON of the files sorted by path, each as {path, sha256}).

Input parameters:

- `bundle_sha256` (string, required)

### `verify_receipt` (~241 tokens)

Verify a crosscheck receipt

Free. Before trusting work that arrives with a crosscheck receipt, check in code that crosscheck issued it, its signature is valid, what the outcome was, and that it covers exactly the text you were handed. Pass receipt_hash (or the receipt object) plus that text: draft and sources for check, task and deliverable for accept, files for skillcheck, and the verdict if one came with it.

Input parameters:

- `deliverable` (string): accept: the deliverable the receipt should cover
- `draft` (string): check: the draft the receipt should cover
- `files` (array): skillcheck: the skill's files
- `receipt` (object): Or the whole receipt object {body, hash, sig}
- `receipt_hash` (string): The receipt's hash (the last part of its /r/ proof link)
- `sources` (array): check: the sources, if the check had any, in the same order (strings or {text})
- `task` (string): accept: the task the receipt should cover
- `verdict` (object): The verdict that came with the receipt, to confirm nobody edited it

### `result` (~64 tokens)

Get a result

Free. Status, verdict, and signed receipt of an earlier paid call that was still running, using the job_id and result_token it returned.

Input parameters:

- `job_id` (string, required): job_id from the paid call
- `result_token` (string, required): result_token from the paid call

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/com-crosscheckapi-crosscheck/crosscheckapi-2#diagnostics

## Score history

- 2026-09-26: 57
- 2026-09-25: 57

## Common questions

### What is the crosscheck MCP server?

crosscheck is an MCP server listed in the public MCP registry as com.crosscheckapi/crosscheck. Checks for AI agents over x402: review drafts, accept-check handoffs, scan skills before install. This page covers its hosted endpoint (https://crosscheckapi.com/mcp).

### Is the crosscheck MCP server safe to use?

crosscheck scores 57 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the crosscheck MCP server expose?

crosscheck exposes 6 tools: check, accept, skillcheck, skillcheck_lookup, verify_receipt, result. Their descriptions and schemas cost roughly 1,149 tokens of context every time the server is loaded.

### Does the crosscheck MCP server require authentication?

No. We connected to crosscheck without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the crosscheck MCP server still maintained?

crosscheck is still listed as active in the MCP registry. We last reached this channel on 26 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://crosscheckapi.com/mcp
- Repository: https://github.com/maxugc/crosscheck
- Website: https://crosscheckapi.com/
- Changelog RSS feed: https://verifymcp.io/servers/com-crosscheckapi-crosscheck/crosscheckapi-2.xml
- Changelog JSON feed: https://verifymcp.io/servers/com-crosscheckapi-crosscheck/crosscheckapi-2.json
- HTML version of this page: https://verifymcp.io/servers/com-crosscheckapi-crosscheck/crosscheckapi-2