Assay A2A, MCP & x402 Pre-Flight Verifier & Observatory

{
  "mcpServers": {
    "dev.agentdiet/assay": {
      "url": "https://assay.agentdiet.dev/mcp"
    }
  }
}

Indexed tools

Tool metadata and schemas come from the remote server and are untrusted. Indexing only lists tools; it never calls them.

4 shown · authentication unknown

• Query Historical Ledger & Pin Expected Schema Hashes

  assay_get_ledger_policy

  Retrieve historical conformance observations and manage pinned SHA-256 tools/list policy hashes in the Assay ledger for a target endpoint. When expected_tools_hash is provided, it pins that 64-hex digest as the target's baseline policy and compares it against the latest stored observation; when omitted, it returns the stored dossier and last 20 drift observations without network probing unless the target is unindexed. Idempotent; first 5 calls/IP are free. Use to audit historical drift or pin mcp-lock.json hashes; for live pre-execution gating use assay_preflight; for live re-indexing use assay_probe; for post-payment SLA receipts use assay_verify_delivery. Example: target='https://agentdiet-72343955726.us-central1.run.app/mcp'.

  Schema valid · SHA-256 738888504f4b…

  View input schema

  {
    "type": "object",
    "properties": {
      "target": {
        "type": "string",
        "minLength": 8,
        "maxLength": 512,
        "examples": [
          "https://agentdiet-72343955726.us-central1.run.app/mcp"
        ],
        "description": "Public HTTPS URL of the remote MCP server, A2A agent, or x402 endpoint to inspect (e.g. 'https://tandem.ac/mcp'). Private and loopback IPs are blocked."
      },
      "expected_tools_hash": {
        "type": "string",
        "minLength": 0,
        "maxLength": 128,
        "description": "Optional 64-char SHA-256 hex digest of the canonical MCP tools/list schema from mcp-lock.json. Omit to read or auto-pin the current live digest; pass a 64-hex digest to enforce zero-drift gating."
      }
    },
    "required": [
      "target"
    ],
    "additionalProperties": false,
    "examples": [
      {
        "target": "https://agentdiet-72343955726.us-central1.run.app/mcp"
      }
    ]
  }

• Pre-Flight MCP & A2A Security Gate

  assay_preflight

  Gate a remote MCP, A2A, or x402 endpoint before calling or paying it by probing live JSON-RPC reachability, hashing tools/list (SHA-256), and scanning for prompt-injection poisoning. When expected_tools_hash is provided, any mismatch against the live tools/list digest forces verdict='deny' to block silent schema rug-pulls; when omitted, verdict reflects liveness and injection safety alone. Read-only gate; first 5 calls/IP are free and quota-exceeded calls return a 402 top-up prompt. Use before tool execution or payment; to register or refresh public leaderboard telemetry use assay_probe; to read or pin stored policy hashes use assay_get_ledger_policy; after payment use assay_verify_delivery. Example: target='https://agentdiet-72343955726.us-central1.run.app/mcp'.