# Merkle-Patricia State Proof for EVM Account and Storage Slot

> Merkle-Patricia State Proof for EVM Account and Storage Slot is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.006/call, status unknown (last checked 2026-10-02).

Returns a cryptographic Merkle-Patricia trie proof for an EVM account's state and an optional storage slot on supported EVM chains

## Facts

- Endpoint: POST https://twin.unykorn.org/evm-proof?utm_source=zero.xyz
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/merkle-patricia-state-proof-for-evm-account-and-storage-slot-8feed360
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cmI0HQkJiHDgyGLsqfJD4

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 merkle-patricia-state-proof-for-evm-account-and-storage-slot-8feed360 -d '<json body>'
```

Example prompt: Can you generate a Merkle-Patricia state proof for the Ethereum address 0xAbCd1234...5678 at the latest block, including storage slot 0x0000000000000000000000000000000000000000000000000000000000000001?

## When to prefer this

Choose this endpoint when you need a cryptographically verifiable Merkle-Patricia trie proof of an EVM account's state or contract storage value — for example, to feed into on-chain bridge verification, light client validation, or trustless cross-chain attestation. Prefer this over reading RPC data directly when the consumer requires proof of inclusion rather than just a value, or when you need to prove a historical state at a specific block number.

## Known failure modes

- Invalid address format (not 0x-prefixed 40-char hex) returns validation error
- Unsupported chain name returns enum validation error
- Nonexistent or pruned block returns proof unavailable error
- Invalid storage slot hex format causes parameter rejection
- Payment failure or insufficient USDC balance returns 402
- Node unavailability on the target chain causes timeout or 503

## How this service works

Merkle-Patricia state proof for an account and optional storage slot — Genesis402 / UnyKorn Operator Network

## Output

Returns a JSON object with ok=true, a type of 'evm-proof', the Merkle-Patricia proof data for the requested account and optional storage slot, and a payment receipt containing the transaction hash, USD amount charged, and a unique receipt ID.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "slot": {
     "type": "string",
     "pattern": "^0x[0-9a-fA-F]*$"
    },
    "block": {
     "type": "string"
    },
    "chain": {
     "enum": [
      "ethereum",
      "base",
      "polygon",
      "arbitrum",
      "optimism",
      "bsc",
      "avalanche",
      "gnosis",
      "linea",
      "scroll"
     ],
     "type": "string"
    },
    "address": {
     "type": "string",
     "pattern": "^0x[0-9a-fA-F]{40}$"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "evm-proof",
  "receipt": {
   "tx_hash": "0x<64hex>",
   "amount_usd": 0.006,
   "receipt_id": "g402-<16hex>"
  },
  "generated_at": "<iso8601>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/merkle-patricia-state-proof-for-evm-account-and-storage-slot-8feed360/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from twin.unykorn.org](https://www.zero.xyz/host/twin.unykorn.org/llms.txt)