# MolCloud Crypto Signature Verifier

> MolCloud Crypto Signature Verifier is a paid API for AI agents from api.molcloud.net, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-17).

Verifies that an EVM wallet signature matches an expected signer address for a given plaintext message

## Facts

- Endpoint: POST https://api.molcloud.net/api/crypto/verify-signature?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/molcloud-crypto-signature-verifier-2e0a0abf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_y5kwFDaSrVsMU4fGzKKIi

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 molcloud-crypto-signature-verifier-2e0a0abf -d '<json body>'
```

Example prompt: Can you verify whether this hex signature '0xabc123...' was actually produced by the wallet address '0xdef456...' for the message 'Login to MyApp at 1234567890'?

## When to prefer this

Use this endpoint when you need a quick, pay-per-request cryptographic signature verification for EVM-compatible wallets without running your own on-chain or local verification infrastructure. Ideal for AI agents that need to authenticate users or instructions via wallet signatures as part of autonomous workflows, especially when settling micropayments in USDC via x402. Prefer this over rolling your own ethers.js/web3 verification when you need a hosted, stateless API call.

## Known failure modes

- Invalid or malformed hex signature string causes verification failure
- Expected signer address is not a valid EVM address format (missing 0x prefix or wrong length)
- Message mismatch — signature valid but for a different message content
- Missing required fields (message, signature, or expectedSigner) returns an error
- Network or gateway error results in a non-200 response
- Payment failure via x402 protocol prevents the request from being processed

## How this service works

40 pay-per-request AI, search, headless browser, crypto alpha & memory APIs for autonomous agents settling in USDC on Base via x402 v2.

## Output

Returns a JSON object with a 'valid' boolean indicating whether the provided hex signature was created by the expected EVM wallet address for the given plaintext message, along with a status string and the endpoint path.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "message": {
   "type": "string",
   "description": "Original signed plaintext message"
  },
  "signature": {
   "type": "string",
   "description": "Hex signature string (0x...)"
  },
  "expectedSigner": {
   "type": "string",
   "description": "Expected EVM wallet address (0x...)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "valid": true
  },
  "status": "success",
  "endpoint": "/api/crypto/verify-signature"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/molcloud-crypto-signature-verifier-2e0a0abf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.molcloud.net](https://www.zero.xyz/host/api.molcloud.net/llms.txt)