Security · x402 · early usage

SENTINEL pre-execution safety verdict

by sentinel-agent.dev · discovered, not yet claimed by its owner · updated 2026-09-30

30d calls2

30d payers1

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

SENTINEL pre-execution safety verdict

Tags: bazaar

Call contract

Method: POST
Input: HTTP request
Output: json
Last paid call: 2026-09-30

No input exampleProvider did not publish one in Bazaar metadata.

Output example

{
  "risks": [],
  "signature": "base64...",
  "verdict": "SAFE"
}

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/55229.json for the price and payment options.
Pay. Call GET https://sentinel-agent.dev/v1/guard. 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, Arbitrum One, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147wwSaGf, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.005 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base, Arbitrum One, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147wwSaGf
Demand: 2 calls · 1 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.005	0xCf1d31020A7915421f6d66B9835Dcb6f422337E7	300s
exact	Arbitrum One eip155:42161	0xaf88d065e58a2e3789859b1b3622c0a25c81f19f	5000	0xCf1d31020A7915421f6d66B9835Dcb6f422337E7	300s
exact	solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147wwSaGf solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147wwSaGf	USDC	$0.005	giu4VciTkfWJNG1oeP6SzHEJwmabikJSMB91GaFNWE4	300s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xCf1d31020A7915421f6d66B9835Dcb6f422337E7",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "5000",
    "amountUsd": 0.005,
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:42161",
    "payTo": "0xCf1d31020A7915421f6d66B9835Dcb6f422337E7",
    "asset": "0xaf88d065e58a2e3789859b1b3622c0a25c81f19f",
    "amount": "5000",
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147wwSaGf",
    "payTo": "giu4VciTkfWJNG1oeP6SzHEJwmabikJSMB91GaFNWE4",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "5000",
    "amountUsd": 0.005,
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

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

{
  "type": "string"
}

Examples

curl

curl -X POST 'https://sentinel-agent.dev/v1/guard'
# -> 402 Payment Required; read PAYMENT-REQUIRED
# retry the identical request with PAYMENT-SIGNATURE

JavaScript

const res = await fetch("https://sentinel-agent.dev/v1/guard", {
  "method": "POST"
});
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.request("POST", "https://sentinel-agent.dev/v1/guard")
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: sentinel-agent.dev
Endpoint: https://sentinel-agent.dev/v1/guard
Machine-readable: /resources/55229.json