# Smart Contract Source Verification Check

> Smart Contract Source Verification Check is a paid API for AI agents from api.strale.io, paid per call via x402, $0.0216/call, status unknown (last checked 2026-10-12).

Checks whether a smart contract's source code is verified on Etherscan, returning compiler version, license type, proxy status, and contract name across 60+ EVM chains.

## Facts

- Endpoint: GET https://api.strale.io/x402/contract-verify-check?utm_source=zero.xyz
- Price: $0.0216/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-strale-io-9c91fe0d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wx-GZ-POHf5EtfVOXgwZW

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 api-strale-io-9c91fe0d
```

Example prompt: Can you check if the contract at 0xdAC17F958D2ee523a2206206994597C13D831ec7 is verified on Etherscan on Ethereum mainnet (chain ID 1) — I want to know the compiler version, license, and whether it's a proxy?

## When to prefer this

Use this endpoint when you need to quickly assess the safety and transparency of a smart contract by checking source code verification status on Etherscan. Ideal for token due diligence, DeFi security checks, and pre-investment screening across any of 60+ EVM-compatible chains. Prefer this over generic blockchain explorers when you need a structured, machine-readable response about verification metadata including proxy detection and license type.

## Known failure modes

- Contract address not found on specified chain — returns unverified or not found status
- Invalid contract address format (not a valid 0x... address) — returns validation error
- Unsupported chain ID — returns error indicating chain is not supported
- Etherscan API unavailable for that chain — may return timeout or upstream error
- Contract exists but has never been verified — returns unverified status with no additional metadata

## How this service works

Check if a smart contract's source code is verified on Etherscan. Returns compiler version, license type, proxy status, and contract name. Unverified contracts are a red flag for token safety. Supports 60+ EVM chains.

## Output

Returns whether the contract source code is verified on Etherscan, along with compiler version, SPDX license type, proxy status (is it a proxy contract), and the contract name. Unverified status is flagged as a red flag for token safety.

## Example request

```json
{
 "chain_id": "1",
 "contract_address": "0xdAC17F958D2ee523a2206206994597C13D831ec7"
}
```

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "contract_address"
     ],
     "properties": {
      "chain_id": {
       "type": "string",
       "description": "Chain ID. Default: 1"
      },
      "contract_address": {
       "type": "string",
       "description": "Smart contract address (0x...)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-strale-io-9c91fe0d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.strale.io](https://www.zero.xyz/host/api.strale.io/llms.txt)