MCP Server
crosscheck
com.crosscheckapi/crosscheck
What this MCP does
Reviews drafts and agent deliverables, verifies requirements and sources, and scans skills or MCP server files for security issues before installation.
Capabilities
Tools
6
tools
accept
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. $0.03 base. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.
Input schema
{'type': 'object', 'required': ['task', 'deliverable'], 'properties': {'ref': {'type': 'string', 'pattern': '^[0-9a-f]{64}$', 'description': 'Optional: the hash of a crosscheck receipt that brought you here. Its wallet earns check credits from your first 90 days of spend.'}, 'task': {'type': 'string', 'description': 'The task as given to the other agent'}, 'reference': {'type': 'string', 'description': 'Optional reference material the task points to'}, 'payment_tx': {'type': 'string', 'description': 'Optional transaction hash of the payment for this work'}, 'deliverable': {'type': 'string', 'description': 'What came back'}, 'payment_network': {'type': 'string', 'description': 'Network of payment_tx, for example eip155:8453'}}}
check
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 request (what the human asked), it also checks the draft answers that. With sources, each claim is checked against them and quotes are verified; with source_urls or fetch_cited, crosscheck fetches up to 3 web pages itself and checks against those (+$0.01 a page, and a dead link the draft gives fails it). $0.02. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.
Input schema
{'type': 'object', 'required': ['draft'], 'properties': {'ref': {'type': 'string', 'pattern': '^[0-9a-f]{64}$', 'description': 'Optional: the hash of a crosscheck receipt that brought you here. Its wallet earns check credits from your first 90 days of spend.'}, 'draft': {'type': 'string', 'maxLength': 48000, 'description': 'The draft text to review'}, 'request': {'type': 'string', 'maxLength': 8000, 'description': 'Optional: what the human asked for, word for word if you have it. The reviewer then also checks that the draft answers it (a missed question, a changed scope, a wrong period)'}, 'sources': {'type': 'array', 'items': {'type': 'object', 'required': ['text'], 'properties': {'url': {'type': 'string', 'description': 'Optional URL'}, 'text': {'type': 'string', 'description': 'Source text'}, 'title': {'type': 'string', 'description': 'Optional title'}}}, 'maxItems': 10, 'description': 'Optional texts the draft relies on; turns on grounding'}, 'fetch_cited': {'type': 'boolean', 'description': 'Optional: also fetch the links the draft itself cites (up to 3 pages in all, +$0.01 each); a link that is gone fails the draft'}, 'open_review': {'type': 'boolean', 'description': "Optional: let a qualified outside reviewer take the job (not routed yet; crosscheck's reviewer does it and the receipt says so)"}, 'source_urls': {'type': 'array', 'items': {'type': 'string', 'description': 'A public http or https URL'}, 'maxItems': 3, 'description': 'Optional: up to 3 web pages crosscheck fetches after payment and checks the draft against, as sources. +$0.01 each'}, 'moltbook_identity': {'type': 'string', 'description': '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'}}}
result
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 schema
{'type': 'object', 'required': ['job_id', 'result_token'], 'properties': {'job_id': {'type': 'string', 'description': 'job_id from the paid call'}, 'result_token': {'type': 'string', 'description': 'result_token from the paid call'}}}
skillcheck
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, $0.03 base. Never says safe. Paid per call in USDC over x402 (Base, or free test USDC on Base Sepolia). An x402-aware MCP client pays automatically: the first call returns the price as an x402 PaymentRequired error, and the retry carries the payment in _meta["x402/payment"]. Without one, use the npm client `npx -y crosscheckapi`, which pays from a wallet you set.
Input schema
{'type': 'object', 'required': ['files'], 'properties': {'ref': {'type': 'string', 'pattern': '^[0-9a-f]{64}$', 'description': 'Optional: the hash of a crosscheck receipt that brought you here. Its wallet earns check credits from your first 90 days of spend.'}, 'files': {'type': 'array', 'items': {'type': 'object', 'required': ['path', 'content'], 'properties': {'path': {'type': 'string', 'description': 'Path inside the skill'}, 'content': {'type': 'string', 'description': 'File content'}}}, 'maxItems': 200, 'minItems': 1, 'description': 'Every text file of the skill or server, docs included; code rules read all of them'}, 'fresh': {'type': 'boolean', 'description': 'Scan again even when a past scan of these exact files exists'}}}
skillcheck_lookup
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 schema
{'type': 'object', 'required': ['bundle_sha256'], 'properties': {'bundle_sha256': {'type': 'string', 'pattern': '^[0-9a-f]{64}$'}}}
verify_receipt
Verify a crosscheck receipt
Free. Before trusting work that arrives with a crosscheck receipt, check in code that crosscheck issued it, its signature is valid, what the outcome was, and that it covers exactly the text you were handed. Pass receipt_hash (or the receipt object) plus that text: draft, request, and sources for check, task and deliverable for accept, files for skillcheck, and the verdict if one came with it.
Input schema
{'type': 'object', 'properties': {'task': {'type': 'string', 'description': 'accept: the task the receipt should cover'}, 'draft': {'type': 'string', 'description': 'check: the draft the receipt should cover'}, 'files': {'type': 'array', 'items': {'type': 'object', 'required': ['path', 'content'], 'properties': {'path': {'type': 'string', 'description': 'Path inside the skill'}, 'content': {'type': 'string', 'description': 'File content'}}}, 'description': "skillcheck: the skill's files"}, 'receipt': {'type': 'object', 'description': 'Or the whole receipt object {body, hash, sig}'}, 'request': {'type': 'string', 'description': "check: the human's request, if the check had one"}, 'sources': {'type': 'array', 'description': 'check: the sources, if the check had any, in the same order (strings or {text})'}, 'verdict': {'type': 'object', 'description': 'The verdict that came with the receipt, to confirm nobody edited it'}, 'deliverable': {'type': 'string', 'description': 'accept: the deliverable the receipt should cover'}, 'receipt_hash': {'type': 'string', 'pattern': '^[0-9a-f]{64}$', 'description': "The receipt's hash (the last part of its /r/ proof link)"}}}
History
Recent tool changes
Added
verify_receipt
Sept. 28, 2026, 2:40 a.m.
Changed
check
Sept. 28, 2026, 2:40 a.m.
Added
result
Sept. 26, 2026, 2:40 a.m.
Added
skillcheck_lookup
Sept. 26, 2026, 2:40 a.m.
Added
skillcheck
Sept. 26, 2026, 2:40 a.m.
Added
accept
Sept. 26, 2026, 2:40 a.m.
Added
check
Sept. 26, 2026, 2:40 a.m.
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