Best-effort contract introspection via batched RPC - bytecode presence, token metadata, an
Best-effort contract introspection via batched RPC - bytecode presence, token metadata, and ERC20-like/ERC721/ERC1155 classification
5000 (raw units)
price
712
calls / 30d
711
unique payers
2026-09-18
updated
Provider
api.onesource.io · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0x52E29e0d2Aa49bfBfC548C0A9F2196F4aa51f3ea",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "5000",
"maxTimeoutSeconds": 3600
},
{
"scheme": "batch-settlement",
"network": "eip155:8453",
"payTo": "0x52E29e0d2Aa49bfBfC548C0A9F2196F4aa51f3ea",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "5000",
"maxTimeoutSeconds": 3600
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"method": "GET",
"pathParams": {
"address": "0xd0601ce157db5bdc3162bbac2a2c8af5320d9eec"
},
"queryParams": {
"network": "ethereum"
},
"type": "http"
},
"output": {
"example": {
"data": {
"address": "0xdac17f958d2ee523a2206206994597c13d831ec7",
"code_length": 11075,
"decimals": 6,
"interfaces": [
"ERC20"
],
"is_contract": true,
"is_erc1155": false,
"is_erc165": false,
"is_erc20": true,
"is_erc721": false,
"name": "Tether USD",
"symbol": "USDT"
},
"meta": {
"cost_usdc": "0.001",
"endpoint": "/api/chain/contract/0xd0601ce157db5bdc3162bbac2a2c8af5320d9eec",
"payment_chain": "base",
"payment_token": "USDC",
"request_id": "00000000abcdef01"
}
},
"type": "json"
}
},
"routeTemplate": "/api/chain/contract/:address",
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"HEAD",
"DELETE"
],
"type": "string"
},
"pathParams": {
"properties": {
"address": {
"pattern": "^0x[a-fA-F0-9]{40}$",
"type": "string"
}
},
"required": [
"address"
],
"type": "object"
},
"queryParams": {
"properties": {
"network": {
"default": "ethereum",
"enum": [
"ethereum",
"sepolia",
"robinhood"
],
"type": "string"
}
},
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"data": {
"description": "Endpoint-specific response payload",
"properties": {
"address": {
"type": "string"
},
"code_length": {
"type": "integer"
},
"decimals": {
"type": "integer"
},
"interfaces": {
"items": {
"type": "string"
},
"type": "array"
},
"is_contract": {
"type": "boolean"
},
"is_erc1155": {
"type": "boolean"
},
"is_erc165": {
"type": "boolean"
},
"is_erc20": {
"type": "boolean"
},
"is_erc721": {
"type": "boolean"
},
"name": {
"type": "string"
},
"symbol": {
"type": "string"
}
},
"type": "object"
},
"error": {
"properties": {
"code": {
"type": "integer"
},
"message": {
"type": "string"
}
},
"type": [
"object",
"null"
]
},
"meta": {
"properties": {
"cost_usdc": {
"type": "string"
},
"endpoint": {
"type": "string"
},
"payment_chain": {
"type": "string"
},
"payment_token": {
"type": "string"
},
"request_id": {
"type": "string"
}
},
"required": [
"endpoint",
"request_id"
],
"type": "object"
}
},
"required": [
"data",
"meta"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://api.onesource.io/api/chain/contract/:address" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://api.onesource.io/api/chain/contract/:address");
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://api.onesource.io/api/chain/contract/:address")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/43.json, and this resource appears in /discovery/resources and /discovery/search.