# BaseLens Address Lookup

> BaseLens Address Lookup is a paid API for AI agents from baselens-api.vercel.app, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Returns on-chain profile data for a Base network address, including ETH/USDC balances, account type, nonce, chain ID, and block context.

## Facts

- Endpoint: GET https://baselens-api.vercel.app/v1/address?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/baselens-address-lookup-be65123a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iWGQoBJvgKpjiQtVL_V9u

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-address-lookup-be65123a
```

Example prompt: Can you look up the on-chain profile for Base address 0x8335...2913 — I want to know if it's a contract or a wallet, and what its ETH and USDC balances are?

## When to prefer this

Choose this endpoint when you need a quick, no-API-key lookup of a Base network address profile — especially ETH/USDC balances and account type — and are willing to pay $0.002 USDC per call via x402. Prefer this over Etherscan-style APIs when operating on Base L2 specifically and want pay-per-call pricing without subscription overhead.

## Known failure modes

- Invalid or malformed 0x address returns an error response
- Address not found on Base mainnet (wrong chain) may return empty or zero balances
- Payment failure via x402 protocol results in HTTP 402 and no data returned
- Rate limiting or network timeouts from the underlying Base RPC node
- USDC balance may reflect ERC-20 token only, not other stablecoins

## 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 the address type (EOA or contract), current block number, nonce, ETH balance, USDC balance, and chain ID (8453 for Base).

## 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": {
  "type": "contract",
  "block": 37000000,
  "nonce": 1,
  "address": "0x8335…2913",
  "chainId": 8453,
  "ethBalance": "0",
  "usdcBalance": "12.5"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/baselens-address-lookup-be65123a/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)