Monitoring · x402 · early usage

Classify a caller-supplied operation claim against caller-supplied evidence under deter…

by verifier.quantumshieldlabs.dev · discovered, not yet claimed by its owner · updated 2026-10-08

30d calls3

30d payers3

MethodPOST

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Classify a caller-supplied operation claim against caller-supplied evidence under deterministic rules and return a machine-readable handoff receipt. Use this when an orchestrator needs a consistent completion state before accepting an agent's work. VERIFIED_COMPLETE means the submitted evidence supports the submitted claim; QSL does not independently observe the underlying real-world action.

Tags: bazaar

Call contract

Method: POST
Input: json
Output: json
Last paid call: 2026-10-08

Input example from Bazaar metadata

{
  "claimed_state": "PASS",
  "evidence_items": [
    {
      "description": "Production health endpoint",
      "name": "health_check",
      "result": true,
      "source": "https://service.example/health"
    }
  ],
  "operation_id": "deploy-42",
  "required_verifications": [
    "health_check"
  ]
}

Output example

{
  "operation_id": "deploy-42",
  "reason_code": "V001",
  "terminal_classification": "VERIFIED_COMPLETE"
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/40180.json for the price and payment options.
Pay. Call GET https://verifier.quantumshieldlabs.dev/x402/verify. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.05 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 3 calls · 3 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.05	0x550205ECa42aAE871CFED6BC943fB2cF59F1d057	300s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x550205ECa42aAE871CFED6BC943fB2cF59F1d057",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "amountUsd": 0.05,
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "additionalProperties": false,
      "properties": {
        "claimed_state": {
          "description": "Echo of the caller-supplied claimed state when provided",
          "type": [
            "string",
            "null"
          ]
        },
        "evidence_accepted": {
          "description": "Names of caller-supplied evidence items accepted by the rules",
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        "evidence_evaluations": {
          "description": "Per-evidence evaluation outcomes",
          "items": {
            "additionalProperties": false,
            "properties": {
              "accepted": {
                "type": "boolean"
              },
              "description": {
                "type": "string"
              },
              "detail": {},
              "name": {
                "type": "string"
              },
              "result_observed": {
                "type": [
                  "boolean",
                  "null"
                ]
              },
              "source": {}
            },
            "required": [
              "name",
              "description",
              "accepted",
              "result_observed",
              "detail",
              "source"
            ],
            "type": "object"
          },
          "type": "array"
        },
        "evidence_insufficient": {
          "description": "Evidence names present but not accepted",
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        "evidence_missing": {
          "description": "Required verification names without accepted evidence",
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        "operation_id": {
          "description": "Echo of the caller-supplied operation identifier",
          "type": "string"
        },
        "reason_code": {
          "description": "Machine-readable reason code (for example V001, C001, E001)",
          "type": "string"
        },
        "reason_description": {
          "description": "Human-readable summary of the reason code",
          "type": "string"
        },
        "receipt_hash": {
          "description": "SHA-256 digest of the receipt payload",
          "type": "string"
        },
        "request_id": {
          "description": "Unique identifier for this receipt",
          "type": "string"
        },
        "terminal_classification": {
          "description": "State assigned by deterministic classification of the caller-supplied claim and evidence",
          "enum": [
            "BLOCKED",
            "CLAIMED_COMPLETE",
            "FAILED",
            "VERIFIED_COMPLETE",
            "WAITING",
            "WORKING"
          ],
          "type": "string"
        },
        "timestamp": {
          "description": "Unix epoch seconds when classification ran",
          "type": "number"
        },
        "verifier_version": {
          "description": "Version of the deterministic verifier core",
          "type": "string"
        },
        "why": {
          "description": "Deterministic explanation of the classification decision",
          "type": "string"
        }
      },
      "required": [
        "terminal_classification",
        "reason_code",
        "operation_id"
      ],
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

Example shape — generated from the schema, not a captured live response

{
  "example": {
    "claimed_state": "string",
    "evidence_accepted": [
      "string"
    ],
    "evidence_evaluations": [
      {
        "accepted": true,
        "description": "string",
        "detail": null,
        "name": "string",
        "result_observed": true,
        "source": null
      }
    ],
    "evidence_insufficient": [
      "string"
    ],
    "evidence_missing": [
      "string"
    ],
    "operation_id": "string",
    "reason_code": "string",
    "reason_description": "string",
    "receipt_hash": "string",
    "request_id": "string",
    "terminal_classification": "BLOCKED",
    "timestamp": 0,
    "verifier_version": "string",
    "why": "string"
  },
  "type": "string"
}

Examples

curl

curl "https://verifier.quantumshieldlabs.dev/x402/verify"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://verifier.quantumshieldlabs.dev/x402/verify");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.get("https://verifier.quantumshieldlabs.dev/x402/verify")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: verifier.quantumshieldlabs.dev
Endpoint: https://verifier.quantumshieldlabs.dev/x402/verify
Machine-readable: /resources/40180.json