Deterministic JSON Verification for Agents

How to run bounded, repeatable assertions over supplied JSON without model inference or external fetching.

When this service fits

Use Agent Verification Utility when an automated workflow already has JSON bytes and needs a small, reproducible check with a signed execution record. Typical uses include checking an expected status field, confirming a required JSON Pointer exists, comparing a value with an exact expected value, or binding downstream work to a known SHA-256 digest.

Do not use it to decide whether a real-world statement is true. The service observes only the bytes supplied by the caller. It does not query an issuer, browse a source, inspect a blockchain event, invoke a model, or execute caller code.

Supported assertions

• sha256_equals: compare the SHA-256 digest of the decoded JSON evidence with an expected digest.
• json_pointer_exists: require that an RFC 6901 JSON Pointer resolves.
• json_pointer_equals: require exact JSON equality at a JSON Pointer.
• json_type_is: require the resolved value to be null, boolean, number, string, array, or object.

Evidence must use media type application/json, decode to no more than 65,536 bytes, and contain 1–16 assertions. The same canonical request is used for quoting, payment, execution, replay protection, and receipt generation.

Minimal request

{

  "client_request_id": "agent-example-001",

  "evidence": {

    "media_type": "application/json",

    "content_base64": "eyJzdGF0dXMiOiJyZWFkeSJ9"

  },

  "assertions": [

    { "op": "json_pointer_equals", "path": "/status", "expected": "ready" }

  ]

}

Machine workflow

1. Read https://agent-economy.kgninja.dev/openapi.json or connect to https://agent-economy.kgninja.dev/mcp.
2. POST { request, spend_policy } to the free precheck and refuse if its spend decision fails.
3. Copy the returned receipt digest into a paid intent without changing the request or policy, then obtain a bound quote through HTTP, MCP, or A2A.
4. Approve and satisfy the x402 challenge only if its binding digest, network, asset, amount, payTo, and expiry match the precheck and quote.
5. Preserve the delivered binding receipt and verify the returned Ed25519 signature with https://agent-economy.kgninja.dev/.well-known/jwks.json.

Interpretation rule

A pass means the named deterministic checks passed over the identified evidence digest. It is intentionally narrower than factual validation, identity verification, provenance validation, or legal attestation. This narrow contract is what makes the output reproducible by another agent.