# Plainchain Address Lookup

> Plainchain Address Lookup is a paid API for AI agents from plainchain.appin60.com, paid per call via x402, $0.001942/call, status unknown (last checked 2026-10-14).

Returns address type classification, ERC-20 token metadata, proxy details, and a human-readable summary for any EVM address on Base, Arbitrum, Ethereum, or Optimism

## Facts

- Endpoint: GET https://plainchain.appin60.com/v1/address?utm_source=zero.xyz
- Price: $0.001942/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/plainchain-address-lookup-d897d0c4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_K0EyDbJxNfKpieYHm_aHv

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 plainchain-address-lookup-d897d0c4
```

Example prompt: Can you tell me what's deployed at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base — is it a contract, what token is it, and is it a proxy?

## When to prefer this

Choose this endpoint when you need a quick, structured classification of any EVM address — whether it's an EOA, a token contract, or an upgradeable proxy — across Base, Arbitrum, Ethereum, and Optimism, without needing an API key. It is ideal for agents that need to enrich address metadata on the fly and can pay micro-fees in USDC via x402. Prefer alternatives if you need deep historical data, transaction history, or non-EVM chains.

## Known failure modes

- Invalid address format (not matching ^0x[0-9a-fA-F]{40}$) returns an error
- Unsupported chain identifier returns an error
- Address is valid but has no on-chain data (e.g. undeployed contract) — type returned as EOA or empty
- Network congestion or RPC failures may cause transient errors
- Payment failure via x402 if insufficient USDC balance on Base

## How this service works

Gas, balances, token data, address type, approvals, transaction decoding, x402 receipt verification and verifiable randomness on Base, Arbitrum, Ethereum and Optimism. No API key: pay $0.001-$0.01 per call in USDC on Base via x402.

## Output

A JSON object containing the address string, chain name, address type (e.g. 'contract' or 'EOA'), ERC-20 metadata (symbol and decimals if applicable), proxy details (standard like EIP-1967, admin address, implementation address if applicable), and a plain-English summary sentence describing what the address is.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "base (default), arbitrum, ethereum or optimism; chain ids 8453, 42161, 1, 10 also work"
      },
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "any address"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "type": "contract",
  "chain": "Base",
  "erc20": {
   "symbol": "USDC",
   "decimals": 6
  },
  "proxy": {
   "admin": "0x3abd...",
   "standard": "EIP-1967",
   "implementation": "0x2ce6..."
  },
  "address": "0x8335...",
  "summary": "ERC-20 token USDC; upgradeable proxy (EIP-1967) -> 0x2ce6..."
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/plainchain-address-lookup-d897d0c4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from plainchain.appin60.com](https://www.zero.xyz/host/plainchain.appin60.com/llms.txt)