# CoinOpSelect Merkle Leaf Lookup API

> CoinOpSelect Merkle Leaf Lookup API is a paid API for AI agents from coinop.publicvm.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-21).

Computes or retrieves a Merkle leaf hash for a given account, index, and amount, used in on-chain Merkle proof workflows on Base.

## Facts

- Endpoint: GET https://coinop.publicvm.com/api/v1/merkle/leaf?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/coinopselect-merkle-leaf-lookup-api-24920dcf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VZYaLNGIn6wfm1wT-O_0K

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 coinopselect-merkle-leaf-lookup-api-24920dcf
```

Example prompt: Look up the Merkle leaf hash for account 0xAbc123... at index 5 with an amount of 1000 — I need it to generate a Merkle proof for a token claim on Base.

## When to prefer this

Use this endpoint when you need to compute or retrieve a Merkle leaf hash for a specific account and amount at a given index, particularly in the context of Merkle distributor contracts, airdrop claims, or whitelist proofs on the Base blockchain. Prefer this over generic Ethereum RPC calls when you need a pre-computed leaf hash without implementing the hashing logic yourself.

## Known failure modes

- Missing required parameters (index, account, or amount) returns a 400 error
- Invalid account address format causes a query failure
- Leaf index out of range returns an empty or null leaf
- Payment not completed via x402 results in a 402 Payment Required response
- Network or RPC issues on Base may cause lookup failures

## How this service works

Paid on-chain token, wallet, contract and research data over x402 on Base.

## Output

Returns a JSON object containing the Merkle leaf as a hex string and a query identifier string. The leaf can be used directly as input to Merkle proof generation or on-chain contract verification calls.

## Request schema (JSON Schema)

```json
{
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "method": {
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "index",
      "account",
      "amount"
     ],
     "properties": {
      "index": {
       "type": "string",
       "description": "Leaf index integer"
      },
      "amount": {
       "type": "string",
       "description": "Amount integer string"
      },
      "account": {
       "type": "string",
       "description": "Account string"
      }
     }
    }
   }
  },
  "output": {
   "type": "object",
   "properties": {
    "leaf": {
     "type": "string"
    },
    "query": {
     "type": "string"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "leaf": "hex",
  "query": "merkle-leaf"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/coinopselect-merkle-leaf-lookup-api-24920dcf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from coinop.publicvm.com](https://www.zero.xyz/host/coinop.publicvm.com/llms.txt)