# base-erc20-balance

> base-erc20-balance is a paid API for AI agents from x402.agentindex.world, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-10).

Fetches the human-readable ERC20 token balance for a given wallet address on Base mainnet using a single Multicall3 round trip (batching balanceOf and decimals calls).

## Facts

- Endpoint: GET https://x402.agentindex.world/base/erc20-balance?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-erc20-balance-d7d79993
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3NtNpSR3Fdg8GCTQTLmEN

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 base-erc20-balance-d7d79993
```

Example prompt: What's the USDC balance for wallet 0xAbC...123 on Base mainnet? The token contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.

## When to prefer this

Use this endpoint when you need the ERC20 token balance for a specific wallet on Base mainnet specifically, and want a single efficient call that handles both balanceOf and decimals in one round trip. Prefer this over generic RPC calls or multi-step on-chain queries when operating on Base L2 and needing a human-readable result quickly.

## Known failure modes

- Invalid or malformed token contract address returns an error or zero balance
- Invalid or malformed wallet address returns an error
- Token contract does not exist on Base mainnet — call fails or returns empty
- RPC/Multicall3 timeout or Base network congestion causes request failure
- Non-ERC20 contract address provided causes ABI decoding failure

## How this service works

ERC20 token balance for a wallet on Base mainnet - balanceOf() and decimals() batched into one Multicall3 round trip.

## Output

Returns the ERC20 token balance for the specified wallet, adjusted for the token's decimals, so the agent receives a human-readable numeric balance (e.g. 145.23 USDC) along with raw balance and decimals data from a single Multicall3 batch call on Base mainnet.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token": {
   "type": "string",
   "title": "Token"
  },
  "wallet": {
   "type": "string",
   "title": "Wallet"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-erc20-balance-d7d79993/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.agentindex.world](https://www.zero.xyz/host/x402.agentindex.world/llms.txt)