# Ethereum Contract Info Lookup

> Ethereum Contract Info Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-18).

Returns contract detection, bytecode size and hash, EIP-1967 and legacy OpenZeppelin proxy slot values, and owner() for a single Ethereum mainnet address.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/eth-contract-info?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ethereum-contract-info-lookup-0bcae728
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_P-iydQXYTl8197Tli0Ic7

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 ethereum-contract-info-lookup-0bcae728 -d '<json body>'
```

Example prompt: Can you check whether 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 is a smart contract on Ethereum mainnet, and if so tell me its bytecode size, bytecode hash, whether it's a proxy, and who the owner is?

## When to prefer this

Choose this endpoint when you need a fast, single-call summary of an Ethereum mainnet address covering contract detection, bytecode fingerprinting, proxy pattern identification (EIP-1967 and legacy OpenZeppelin), and ownership — without writing custom RPC calls. It is read-only with no side effects, making it safe for audits, pipelines, and agent workflows. Use the free sandbox endpoint (/v1/sandbox/eth-contract-info) first to validate integration before paying $0.003 USDC per call on Base.

## Known failure modes

- Invalid Ethereum address format — returns error indicating malformed input
- Address not found or network unreachable — may return error or empty result
- Contract has no owner() function — owner field absent or null in response
- Payment not included or insufficient — 402 Payment Required response; use /v1/sandbox/eth-contract-info for free testing
- Rate limiting or upstream Ethereum node failure — transient 5xx error

## How this service works

Call when an agent needs is_contract, bytecode size and hash, EIP-1967 and legacy OpenZeppelin proxy slots, and owner() for one Ethereum mainnet address. An EOA is is_contract false. Read-only. No spend. Send JSON {"address":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"}. Exact $0.003 USDC on Base. Try unpaid POST /v1/sandbox/eth-contract-info first.

## Output

A JSON object containing: is_contract (boolean indicating contract vs EOA), bytecode_size (integer byte count), bytecode_hash (keccak256 hash of deployed bytecode), EIP-1967 proxy implementation slot value, legacy OpenZeppelin proxy slot value, and owner() return value if the contract exposes it.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "address": {
   "type": "string",
   "examples": [
    "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
   ],
   "description": "Account on Ethereum mainnet. Example: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 (Circle USDC). Returns is_contract, bytecode size and hash, proxy slots, and owner() when present. An EOA is is_contract false."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ethereum-contract-info-lookup-0bcae728/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)