# BaseLens Contract Verification Lookup

> BaseLens Contract Verification Lookup is a paid API for AI agents from baselens-api.vercel.app, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-31).

Returns contract verification status, owner, proxy implementation, and Sourcify metadata for a given Base blockchain address

## Facts

- Endpoint: GET https://baselens-api.vercel.app/v1/contract?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/baselens-contract-verification-lookup-7d6b2933
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IIrcrD8NS_5sCcrt8KN85

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 baselens-contract-verification-lookup-7d6b2933
```

Example prompt: Is the contract at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base verified? I want to know the contract name, whether it's a proxy, and who owns it.

## When to prefer this

Use this endpoint when you need to verify whether a Base blockchain address is a smart contract, check its Sourcify verification status, discover proxy/implementation relationships, or identify contract ownership — all without managing an API key, paying only $0.003 USDC per call via x402.

## Known failure modes

- Invalid or malformed address returns an error
- EOA (non-contract) addresses return isContract: false with limited data
- Unverified contracts return verified: false with no Sourcify name
- Rate limiting or payment failures via x402 protocol
- Address not found on Base mainnet

## How this service works

Base address, ERC-20 balance, token price, recent transfers, Basename/ENS resolve, contract verification, tx summaries and gas over x402 and MCP. $0.001–$0.004 USDC per call, no API key.

## Output

A JSON object containing: isContract (boolean), owner address, Sourcify verification details (name, match type, verified flag), proxy implementation address if applicable, and any notes about upgradeability or contract structure.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "description": "0x-prefixed Base address"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "notes": [
   "Upgradeable proxy…"
  ],
  "owner": "0x3ABd…6df7",
  "sourcify": {
   "name": "FiatTokenProxy",
   "match": "exact_match",
   "verified": true
  },
  "isContract": true,
  "proxyImplementation": "0x2Ce6…D779"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/baselens-contract-verification-lookup-7d6b2933/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from baselens-api.vercel.app](https://www.zero.xyz/host/baselens-api.vercel.app/llms.txt)