# Vextorium Smart Contract Verification Checker

> Vextorium Smart Contract Verification Checker is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-01).

Checks whether a smart contract's source code is verified on Sourcify for any EVM chain, returning match type, contract name, compiler, function list, and verification date.

## Facts

- Endpoint: POST https://api.vextorium.com/contrato-verificado-pago?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-smart-contract-verification-checker-644a338e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Wfn5tilyx6LLEmxZg00tU

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability vextorium-smart-contract-verification-checker-644a338e -d '<json body>'
```

Example prompt: Can you check whether the smart contract at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum is verified on Sourcify — I want to know the match type, contract name, compiler, and what functions it exposes?

## When to prefer this

Use this endpoint when you need to confirm whether a smart contract's source code is publicly available and verified on Sourcify across any EVM-compatible chain. It's ideal for transparency checks before interacting with a DeFi protocol, auditing a contract, or surfacing readable function names. Prefer it over block explorer APIs when you want a single unified check across multiple chains (Ethereum, Base, Arbitrum, Optimism, Polygon, BSC, etc.) with structured output including compiler and function metadata.

## Known failure modes

- Contract address not found on Sourcify — returns verified: false with null fields
- Invalid or unsupported chain identifier — may return error or unrecognized chain response
- Malformed contract address (non-0x format) — validation error
- Contract exists on-chain but source was never submitted to Sourcify — returns unverified result
- Network timeout reaching Sourcify API — upstream latency error

## How this service works

Checks whether a smart contract's source code is verified and public on Sourcify, on any EVM chain: match type, contract name, compiler, number of functions and a sample. Verified code = transparent and auditable (not a safety guarantee). Live from Sourcify.

## Output

Returns a JSON object with: verified (boolean), match type (exact/partial), contract name, compiler version, number of functions, a sample list of function names, verification date, chain name, chain ID, contract address, and a source/note field linking back to Sourcify.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "required": [
      "direccion"
     ],
     "properties": {
      "red": {
       "type": "string",
       "description": "Chain: ethereum, base, arbitrum, optimism, polygon, bsc… or a chainId"
      },
      "direccion": {
       "type": "string",
       "description": "Contract address (0x…)"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": [
      "object",
      "null"
     ],
     "properties": {
      "red": {
       "type": [
        "string",
        "null"
       ]
      },
      "nota": {
       "type": [
        "string",
        "null"
       ]
      },
      "fuente": {
       "type": [
        "string",
        "null"
       ]
      },
      "chain_id": {
       "type": [
        "number",
        "null"
       ]
      },
      "direccion": {
       "type": [
        "string",
        "null"
       ]
      },
      "funciones": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": [
         "null",
         "string"
        ]
       }
      },
      "compilador": {
       "type": [
        "string",
        "null"
       ]
      },
      "verificado": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "coincidencia": {
       "type": [
        "string",
        "null"
       ]
      },
      "num_funciones": {
       "type": [
        "number",
        "null"
       ]
      },
      "verificado_el": {
       "type": [
        "string",
        "null"
       ]
      },
      "nombre_contrato": {
       "type": [
        "string",
        "null"
       ]
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "red": "ethereum",
  "nota": "Código verificado = lo que hace el contrato es público y auditable. No garantiza que sea seguro. Fuente: Sourcify.",
  "fuente": "Sourcify (sourcify.dev)",
  "chain_id": 1,
  "direccion": "0xdAC17F958D2ee523a2206206994597C13D831ec7",
  "funciones": [
   "name",
   "deprecate",
   "approve",
   "deprecated",
   "addBlackList",
   "totalSupply",
   "transferFrom",
   "upgradedAddress",
   "balances",
   "decimals",
   "maximumFee",
   "_totalSupply",
   "unpause",
   "getBlackListStatus",
   "allowed",
   "paused",
   "balanceOf",
   "pause",
   "getOwner",
   "owner"
  ],
  "compilador": "0.4.18+commit.9cf6e910",
  "verificado": true,
  "coincidencia": "match",
  "num_funciones": 32,
  "verificado_el": "2024-08-08T13:56:23Z",
  "nombre_contrato": "TetherToken"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-smart-contract-verification-checker-644a338e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)