Identity & Enrichment · x402 · early usage

Profile a Base address in one call instead of four to six lookups

by chainstate.schemasure.com · discovered, not yet claimed by its owner · updated 2026-10-11

30d calls28

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

Profile a Base address in one call instead of four to six lookups. Returns contract or externally owned plus code size, proxy detection across all seven slot layouts including the legacy OpenZeppelin slot Base USDC uses, the resolved implementation, ERC-165 and behavioural ERC-20 detection, token metadata, requested ERC-20 balances, and denylist hits. Answers unknown rather than guessing, and null rather than false when a contract stays silent. Not a guarantee that an address is safe.

Tags: base · address · proxy · erc20 · erc165 · bazaar

Call contract

Method: POST
Input: json
Output: json
Last paid call: 2026-10-11

Input example from Bazaar metadata

{
  "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
}

Output example

{
  "confidence": 1,
  "data_versions": {
    "abi_packs": "2026-08-03.1",
    "chain": "eip155:8453",
    "denylist": "2026-08-03.1",
    "policy": "2026-09-19",
    "proxy_slots": "7"
  },
  "evidence": [
    {
      "code": "INTERFACE_PROBE_UNANSWERED",
      "detail": "This contract did not answer supportsInterface, so ERC-721 and ERC-1155 support is reported as null. That is not evidence against them: plenty of live contracts predate ERC-165 entirely.",
      "severity": "info",
      "source": "erc165"
    },
    {
      "code": "PROXY_UPGRADEABLE",
      "data": {
        "admin": "0x4fc7850364958d97B4d3f5A08f79db2493f8cA44",
        "implementation": "0x2Ce6311ddAE708829bc0784C967b7d77D19FD779",
        "kind": "zeppelinos"
      },
      "detail": "This is an upgradeable zeppelinos proxy. Everything reported here describes the implementation deployed right now; the admin can point it elsewhere before your next call lands, so this is a risk signal rather than metadata.",
      "severity": "medium",
      "source": "proxy-slots"
    }
  ],
  "ok": true,
  "policy_version": "2026-09-19",
  "request_hash": "sha256:96b41fa639c553a6dc6bfaa1d8ccc056912abc36e8bbde3d65f3e1edc2bd147f",
  "result": {
    "account": {
      "code_size": 1852,
      "detail": "1852 bytes of runtime code",
      "is_contract": true
    },
    "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "balances": [],
    "chain": "eip155:8453",
    "denylist_hits": [],
    "interfaces": {
      "detail": "supportsInterface did not answer, so ERC-721 and ERC-1155 are reported as unknown rather than absent; ERC-20 is confirmed behaviourally from totalSupply, decimals, and balanceOf",
      "erc1155": null,
      "erc165": null,
      "erc20": true,
      "erc721": null
    },
    "proxy": {
      "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "admin": "0x4fc7850364958d97B4d3f5A08f79db2493f8cA44",
      "beacon": null,
      "detail": "resolved through the legacy zeppelinos slot; the EIP-1967 slot is empty on this contract, which is the case for Base USDC",
      "implementation": "0x2Ce6311ddAE708829bc0784C967b7d77D19FD779",
      "kind": "zeppelinos",
      "slots_probed": [
        {
          "address": "0x2Ce6311ddAE708829bc0784C967b7d77D19FD779",
          "label": "zeppelinos.implementation",
          "slot": "0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3",
          "value": "0x0000000000000000000000002ce6311ddae708829bc0784c967b7d77d19fd779"
        },
        {
          "address": "0x4fc7850364958d97B4d3f5A08f79db2493f8cA44",
          "label": "zeppelinos.admin",
          "slot": "0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b",
          "value": "0x0000000000000000000000004fc7850364958d97b4d3f5a08f79db2493f8ca44"
        }
      ],
      "upgradeable": true
    },
    "rpc": {
      "configured": true,
      "endpoints": [],
      "reachable": true
    },
    "token": {
      "decimals": 6,
      "detail": "symbol, decimals, and totalSupply read from the token",
      "symbol": "USDC",
      "total_supply": "4305008625389354"
    },
    "unresolved": [
      "ERC-165 interface support: supportsInterface did not answer"
    ]
  },
  "risk_codes": [
    "PROXY_UPGRADEABLE"
  ],
  "verdict": "warn",
  "warnings": []
}

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/36259.json for the price and payment options.
Pay. Call GET https://chainstate.schemasure.com/v1/chain/state. 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: $0.02 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 28 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	$0.02	0x9876af0F6D8Ed5155Cd02d1ca56D128601612690	60s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x9876af0F6D8Ed5155Cd02d1ca56D128601612690",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "amountUsd": 0.02,
    "maxTimeoutSeconds": 60
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "properties": {
        "result": {
          "required": [
            "address",
            "account",
            "proxy",
            "interfaces",
            "token",
            "balances",
            "unresolved"
          ],
          "type": "object"
        },
        "verdict": {
          "description": "Precedence: block, then unknown, then warn, then allow.",
          "enum": [
            "allow",
            "warn",
            "block",
            "unknown"
          ],
          "type": "string"
        }
      },
      "required": [
        "ok",
        "verdict",
        "risk_codes",
        "evidence",
        "result",
        "request_hash"
      ],
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

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

{
  "example": {
    "result": {},
    "verdict": "allow"
  },
  "type": "string"
}

Examples

curl

curl "https://chainstate.schemasure.com/v1/chain/state"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://chainstate.schemasure.com/v1/chain/state");
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://chainstate.schemasure.com/v1/chain/state")
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: chainstate.schemasure.com
Endpoint: https://chainstate.schemasure.com/v1/chain/state
Machine-readable: /resources/36259.json