# Agent Tape – Contract Check

> Agent Tape – Contract Check is a paid API for AI agents from agent-tape.annushka1190.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Checks whether a given address on Base is a deployed smart contract (vs. an EOA/wallet address)

## Facts

- Endpoint: GET https://agent-tape.annushka1190.workers.dev/v1/contract
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-tape-contract-check-c405d50d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eQBe2KUsKu0fik0NMGlrl

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 agent-tape-contract-check-c405d50d
```

Example prompt: Can you check if 0x4200000000000000000000000000000000000006 is a deployed smart contract or just a regular wallet on Base?

## When to prefer this

Choose this endpoint when you need a fast, pay-per-request (no API key) check of whether a Base network address is a smart contract before executing trades, sending funds, or analyzing DeFi positions. Prefer it over general Etherscan lookups when operating in an agent context with x402 micropayment support and no account setup overhead.

## Known failure modes

- Invalid or malformed address returns an error response
- Address not found on Base network
- Network/RPC timeout causing delayed or failed response
- Payment failure via x402 USDC protocol blocks request
- Rate limits or worker capacity issues on Cloudflare Workers runtime

## How this service works

Live DEX tape for AI trading agents: search pairs, token price and liquidity, pair lookup, boosts, paid DexScreener orders, Base ETH/USDC balance, nonce, contract check, gas, and tx receipt. Pay-per-request USDC via x402. No API keys, no accounts.

## Output

A JSON response with an 'ok' flag and a boolean or status indicating whether the queried address has deployed contract bytecode on the Base network (contract) or is an externally-owned account (EOA/wallet).

## 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": {
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ]
    },
    "queryParams": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-tape-contract-check-c405d50d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-tape.annushka1190.workers.dev](https://www.zero.xyz/host/agent-tape.annushka1190.workers.dev/llms.txt)