# Multicall3 Batch eth_call

> Multicall3 Batch eth_call is a paid API for AI agents from x402-audit.tatschluizguilherme.workers.dev, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-16).

Executes up to 20 read-only Ethereum calls in a single batched request via the Multicall3 contract on Base, Optimism, or Ethereum Mainnet, returning per-call success flags, return data, block number, and gas estimate

## Facts

- Endpoint: GET https://x402-audit.tatschluizguilherme.workers.dev/multicall
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/multicall3-batch-eth-call-5381a070
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0qykj1CHTejHzgprILZ-f

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 multicall3-batch-eth-call-5381a070
```

Example prompt: Batch these 5 on-chain reads for me on Base in one multicall: get the ETH balance of 0xABC, the USDC balance of 0xDEF, the USDC allowance of 0xDEF for Uniswap router 0x123, the total supply of token 0x456, and the owner of NFT contract 0x789 — I want all results plus the block number and per-call success flags.

## When to prefer this

Choose this endpoint when you need to aggregate multiple read-only on-chain data points (balances, allowances, contract state) in a single round trip, avoiding multiple sequential RPC calls. Ideal for DeFi dashboards, portfolio trackers, or any agent workflow requiring 2–20 contract reads at the same block. Prefer over individual balance/allowance endpoints when fetching 3 or more values from the same or different contracts on Base, Optimism, or Ethereum Mainnet.

## Known failure modes

- More than 20 calls submitted — batch limit exceeded
- Invalid calldata encoding causes individual call to revert (returned as success:false)
- Unsupported chain ID — only Base, Optimism, Ethereum Mainnet accepted
- Malformed request body returns 400 error
- Network congestion or RPC timeout causes full batch failure
- Contract address does not exist on the specified chain — success:false returned

## How this service works

Pay-per-call on-chain API for AI agents and developers: wallet audits, token safety audits (honeypot detection), live gas prices, token prices, transaction receipts, balances, ENS resolution, block data, ERC-20 allowances, transaction simulation, swap quotes and multicall batches — all computed on-chain via public RPCs (no external market API). Pay per request in USDC on Base via the x402 exact scheme (EIP-3009 transferWithAuthorization). No API key, no signup, no subscription.

## Output

An array of per-call results each containing a success boolean and raw returnData (hex), plus the blockNumber at which the batch was executed and an overall gas estimate for the batch. A call that reverts returns success:false without causing the entire batch to fail.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "calls": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "calls": [
   {
    "to": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
    "data": "0x70a082310000000000000000000000008e8d53a67b59e6f2a28e0d6d52012a2b0e3e1886",
    "success": true,
    "returnData": "0x0000000000000000000000000000000000000000000000000000000000000000"
   }
  ],
  "network": "base",
  "callCount": 2,
  "multicall3": "0xcA11bde05977b3631167028862bE2a173976CA11",
  "blockNumber": 24400123,
  "gasEstimate": 61458,
  "requestedAt": "2026-08-05T02:20:00.000Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/multicall3-batch-eth-call-5381a070/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-audit.tatschluizguilherme.workers.dev](https://www.zero.xyz/host/x402-audit.tatschluizguilherme.workers.dev/llms.txt)