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clearsigned-mcp

clearsigned-mcp

by diawest82
OverviewSchemaSourceRelated ServersDiscussionsAdmin
Python
Hybrid

clearsigned-mcp

An MCP server that gives any agent a verify_claim tool: calibrated claim verification against live web evidence, paid per call over x402 ($0.05 USDC on Base), with an Ed25519-signed receipt the server verifies offline against Clearsigned's pinned published key before your agent sees it.

Tools

Tool

Paid?

What it returns

verify_claim(claim, evidence?)

$0.05 USDC

SUPPORTED / REFUTED / UNVERIFIABLE, calibrated confidence (a measured realized rate), per-source stances, receipt id, settlement tx, signature_verified_offline

quote()

free

the price an unpaid request is quoted right now, decoded from the 402

service_status()

free

what is serving, ledger height, published buyer counts

UNVERIFIABLE is a real answer, not an error: the engine abstains instead of guessing. The price never depends on the verdict; refunds exist only for failure to deliver. A request with no claim is refused locally, before any payment.

Related MCP server: VerifyAPI MCP Server

Install

pip install clearsigned-mcp        # or: pipx install clearsigned-mcp
export CLEARSIGNED_BUYER_KEY=0x…   # an EVM key holding a little USDC on Base mainnet
clearsigned-mcp                    # stdio transport

Claude Desktop / Claude Code / any MCP client:

{
  "mcpServers": {
    "clearsigned": {
      "command": "clearsigned-mcp",
      "env": { "CLEARSIGNED_BUYER_KEY": "0x…" }
    }
  }
}

The key signs x402 payment authorizations wherever this server runs: on your machine for a local install, or on the registry's runner if you connect through a hosted URL (Smithery offers one). It is never sent to Clearsigned; the service sees the payment, not the key.

How to check us

Source of truth

This package is developed inside the Clearsigned monorepo (products/mcp-server/) and mirrored to a public repository for registries and installs. Issues and pull requests on the mirror are welcome; changes land in the monorepo first.

Development

python -m pytest tests/

The tests never touch the network or a wallet: the exchange is injected, and receipts are signed with a throwaway Ed25519 key to exercise the offline verification exactly as production does it.

Available Tools

3 tools
quoteA

Free. The price an unpaid request is quoted right now (USDC atomic units, asset, network, scheme, pay-to address), decoded from the service's HTTP 402 challenge.

Inputs: no named parameters.

service_statusA

Free. What the service is serving (calibrated engine or stub, curve version), the public ledger height, and the published buyer counts (receipts, distinct payers, external payers).

Inputs: no named parameters.

verify_claimA

Verify one factual claim (PAID: $0.05 USDC over x402). Returns verdict, calibrated confidence, per-source stances, receipt id, settlement transaction, and whether the receipt's signature verified offline against the pinned published key. Optional evidence: strings the caller already holds, admitted as secondary-tier evidence. Takes about 5-15 seconds.

Inputs: claim (required), evidence.

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections.

Loading tool schema changelog…

    Deploy Server
    One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

    TDQS

    A3.9/5.0

    Scored across 3 tools

    Disambiguation5/5

    Each tool serves a completely distinct purpose: verify_claim handles paid claim verification, quote provides pricing information, and service_status reports operational metrics. There is no overlap or ambiguity between them.

    Naming Consistency4/5

    Names are clear and follow a lowercase_with_underscores convention, but the pattern is not uniform: verify_claim is verb_noun, quote is a bare verb, and service_status is noun_noun. This minor inconsistency is easily readable.

    Tool Count4/5

    With only 3 tools, the set is on the smaller side, but it is well-scoped for a focused service that offers claim verification, pricing, and status. Each tool earns its place without feeling sparse.

    Completeness4/5

    The core workflow of verifying a single claim is fully covered, along with necessary supporting operations for pricing and status. A potential gap is lack of batch verification, but that may be outside the intended scope.

    Maintenance

    ActivityNo data
    ResponsivenessOutdated data

    Resources

    Related MCP Connectors

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