# santyvv-data: Ethereum Address Contract Detection (Bytecode Size)

> santyvv-data: Ethereum Address Contract Detection (Bytecode Size) is a paid API for AI agents from santyvv-x402.santyvv1993.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-01).

Checks whether an Ethereum address is a smart contract by returning its bytecode size

## Facts

- Endpoint: GET https://santyvv-x402.santyvv1993.workers.dev/api/chain/code?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/santyvv-data-ethereum-address-contract-detection-bytecode-size-9fb5db36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zf5MzGvjXQ0UaO_OKJAtY

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 santyvv-data-ethereum-address-contract-detection-bytecode-size-9fb5db36
```

Example prompt: Can you check if the Ethereum address 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 is a smart contract or a regular wallet?

## When to prefer this

Use this endpoint when you need a lightweight, cheap check to determine if an Ethereum address hosts deployed bytecode (i.e., is a smart contract) versus a regular wallet. Ideal before executing contract interactions, verifying token addresses, or auditing unknown addresses. Prefer over full bytecode retrieval if you only need to confirm contract presence, not inspect the code itself.

## Known failure modes

- Invalid or malformed Ethereum address returns an error
- Network or RPC timeout causes request failure
- Address exists but is on a chain not supported by this endpoint
- Missing or invalid payment header causes 402 response
- Empty or missing input parameter returns validation error

## How this service works

Is this address a contract? Bytecode size

## Output

Returns the bytecode size of the given Ethereum address. A bytecode size greater than zero indicates the address is a deployed smart contract; a size of zero indicates it is an externally owned account (regular wallet). This allows agents to definitively distinguish contracts from EOAs.

## 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",
     "properties": {}
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/santyvv-data-ethereum-address-contract-detection-bytecode-size-9fb5db36/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from santyvv-x402.santyvv1993.workers.dev](https://www.zero.xyz/host/santyvv-x402.santyvv1993.workers.dev/llms.txt)