# Xerxes Base Wallet Snapshot

> Xerxes Base Wallet Snapshot is a paid API for AI agents from ari001.tailb4ac3a.ts.net, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Returns a snapshot of a Base address at the chain head: native ETH balance, nonce, and contract status, with optional ERC-20 balance lookup via query parameter.

## Facts

- Endpoint: GET https://ari001.tailb4ac3a.ts.net/v1/base/wallet/:addr
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/xerxes-base-wallet-snapshot-0500b9d9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tojJqbaWoM7Lf_QvmD6aq

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 xerxes-base-wallet-snapshot-0500b9d9
```

Example prompt: What's the current ETH balance, nonce, and whether it's a contract for Base address 0x742d35Cc6634C0532925a3b8D4C9C0F2b9E1234 — and also check its USDC balance?

## When to prefer this

Use this endpoint when you need a quick, lightweight snapshot of a Base address at the current chain head — covering native ETH balance, nonce, and contract detection in a single call. Prefer this over full block explorers or multicall setups when you only need head-state data for one address. Use the optional ?token= parameter to also fetch a single ERC-20 balance without a separate call. Do not use this if you need historical balances, USD-denominated quotes, or balances at a specific block number.

## Known failure modes

- Invalid or malformed 0x address returns a 4xx error
- RPC node unavailable: field returned as unread/null, not zero — agent must distinguish null from 0
- ERC-20 token address invalid or not a valid ERC-20 contract: token balance call may fail or return null
- 402 Payment Required if x402 payment not attached
- Address not found on Base (address never used) still returns nonce=0 and balance=0 — valid response

## How this service works

Base wallet snapshot at head: native ETH balance, nonce, is_contract. Optional ERC-20 balanceOf via ?token=. One 402, parallel RPC. No USD quote. Dead RPC is unread, not zero.

## Output

Returns a JSON object containing the address's native ETH balance (in wei or formatted), nonce (transaction count), and a boolean is_contract flag indicating whether the address is a deployed smart contract. If the ?token= query parameter is provided with an ERC-20 contract address, also returns the ERC-20 balanceOf result. Note: if the underlying RPC is unreachable, the field is returned as unread/null rather than zero, to distinguish from a genuine zero balance.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "addr"
     ],
     "properties": {
      "addr": {
       "type": "string",
       "description": "20-byte 0x address on Base"
      }
     }
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/xerxes-base-wallet-snapshot-0500b9d9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ari001.tailb4ac3a.ts.net](https://www.zero.xyz/host/ari001.tailb4ac3a.ts.net/llms.txt)