# Agent Rest Stop – EIP-55 Address Checksum

> Agent Rest Stop – EIP-55 Address Checksum is a paid API for AI agents from agent-gas-station.agent-gas-station.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).

Returns the EIP-55 checksummed version of an Ethereum address along with a short list of supported chain IDs

## Facts

- Endpoint: POST https://agent-gas-station.agent-gas-station.workers.dev/v1/Checksum?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-rest-stop-eip-55-address-checksum-4009ceea
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cyW2PjyWUgQR9eOgCRxsx

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 agent-rest-stop-eip-55-address-checksum-4009ceea -d '<json body>'
```

Example prompt: Can you checksum this Ethereum address for me — 0xd8da6bf26964af9d7eed9e03e53415d37aa96045 — on chain ID 1?

## When to prefer this

Use this endpoint when you need a quick, cheap ($0.01 USDC) on-demand EIP-55 checksum conversion without standing up your own Web3 library. Particularly useful in agent pipelines that handle user-supplied wallet addresses and need to normalize them before display, storage, or on-chain use. Prefer this over a full Web3 node call when you only need address formatting, not broader blockchain interaction.

## Known failure modes

- Invalid hex address format — returns error if the input is not a valid 40-character hex string
- Unsupported chain ID — may return an error or ignore chain-specific nuances if the chain_id is not in the supported list
- Missing address field — request fails validation if address is omitted
- Malformed input object — non-string values cause schema validation errors

## How this service works

EIP-55 checksum plus a short chain-id list.

## Output

Returns the EIP-55 mixed-case checksummed representation of the submitted address, plus a short list of chain IDs that the service supports, enabling the caller to confirm address formatting correctness and understand chain compatibility.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "address": {
   "type": "string"
  },
  "chain_id": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-rest-stop-eip-55-address-checksum-4009ceea/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-gas-station.agent-gas-station.workers.dev](https://www.zero.xyz/host/agent-gas-station.agent-gas-station.workers.dev/llms.txt)