AP
MCP Tool · x402 · early usage

Which agents registered on Arc actually answer

Which agents registered on Arc actually answer. Every endpoint every agent lists in its ERC-8004 registration file (web, A2A, MCP, x402, the file itself) is called once an hour through an address-checked fetcher: A2A cards are read, MCP servers get the initia…

by apexfaucet.xyz · discovered, not yet claimed by its owner · updated 2026-10-08

30d calls5
30d payers3
MethodGET
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

Which agents registered on Arc actually answer. Every endpoint every agent lists in its ERC-8004 registration file (web, A2A, MCP, x402, the file itself) is called once an hour through an address-checked fetcher: A2A cards are read, MCP servers get the initialize handshake, x402 paywalls are parsed the way a standard client would and checked against the on-chain EIP-712 domains of USDC and EURC on Arc (a wrong domain means every signature fails - we name it).

Tags: uptime · erc-8004 · arc · ai agents · health check · bazaar

Call contract

Method
GET
Input
HTTP request
Output
json
Last paid call
2026-10-08
No input exampleProvider did not publish one in Bazaar metadata.
Output example
{
  "data": {
    "ageSeconds": 785,
    "agents": [],
    "chain": "arc",
    "chainId": 5042,
    "hour": "2026-10-06T04",
    "lastRound": {},
    "measuredAt": "2026-10-06T04:56:47.061Z",
    "method": {},
    "ok": true,
    "registry": "0x8004A169FB4a3325136EB2…",
    "summary": {},
    "tier": "full"
  },
  "ok": true,
  "paid": 0.004
}

Use with an agent

  1. Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
  2. Inspect. Fetch /resources/51488.json for the price and payment options.
  3. Pay. Call GET https://apexfaucet.xyz/api/x402/arc-agent-watch. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
  4. 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, eip155:5042, Solana, eip155:56, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price
$0.004 / request
Protocol
x402 v2
Auth
No account or API key. Pay per request.
Networks
Base, eip155:5042, Solana, eip155:56
Demand
5 calls · 3 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

SchemeNetworkAssetAmountPay toTimeout
exactBase
eip155:8453
USDC$0.0040xd334ab5151c624cada654854e2879903dc4217ed300s
exacteip155:5042
eip155:5042
0x360000000000000000000000000000000000000040000xd334ab5151c624cada654854e2879903dc4217ed300s
exacteip155:5042
eip155:5042
0x360000000000000000000000000000000000000040000xd334ab5151c624cada654854e2879903dc4217ed604900s
exactBase
eip155:8453
USDC$0.0040xd334ab5151c624cada654854e2879903dc4217ed604900s
exactSolana
solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp
USDC$0.004HYiepS7mNCVVKoaDmZLQ6rNtMWHTQqKheM1NLGn1x8kJ300s
exacteip155:56
eip155:56
0x8d0D000Ee44948FC98c9B98A4FA4921476f08B0d100000000000000000xd334AB5151C624cAdA654854E2879903Dc4217eD300s
exacteip155:56
eip155:56
0xcE24439F2D9C6a2289F741120FE202248B666666100000000000000000xd334AB5151C624cAdA654854E2879903Dc4217eD300s
accepts[] (raw JSON)
[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xd334ab5151c624cada654854e2879903dc4217ed",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "4000",
    "amountUsd": 0.004,
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:5042",
    "payTo": "0xd334ab5151c624cada654854e2879903dc4217ed",
    "asset": "0x3600000000000000000000000000000000000000",
    "amount": "4000",
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:5042",
    "payTo": "0xd334ab5151c624cada654854e2879903dc4217ed",
    "asset": "0x3600000000000000000000000000000000000000",
    "amount": "4000",
    "maxTimeoutSeconds": 604900
  },
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xd334ab5151c624cada654854e2879903dc4217ed",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "4000",
    "amountUsd": 0.004,
    "maxTimeoutSeconds": 604900
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "payTo": "HYiepS7mNCVVKoaDmZLQ6rNtMWHTQqKheM1NLGn1x8kJ",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "4000",
    "amountUsd": 0.004,
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:56",
    "payTo": "0xd334AB5151C624cAdA654854E2879903Dc4217eD",
    "asset": "0x8d0D000Ee44948FC98c9B98A4FA4921476f08B0d",
    "amount": "10000000000000000",
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:56",
    "payTo": "0xd334AB5151C624cAdA654854E2879903Dc4217eD",
    "asset": "0xcE24439F2D9C6a2289F741120FE202248B666666",
    "amount": "10000000000000000",
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)
{
  "type": "object"
}
Example shape — generated from the schema, not a captured live response
{}

Examples

curl
curl "https://apexfaucet.xyz/api/x402/arc-agent-watch"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://apexfaucet.xyz/api/x402/arc-agent-watch");
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://apexfaucet.xyz/api/x402/arc-agent-watch")
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
apexfaucet.xyz
Endpoint
https://apexfaucet.xyz/api/x402/arc-agent-watch
Machine-readable
/resources/51488.json