# X Pay Keccak256 Hash

> X Pay Keccak256 Hash is a paid API for AI agents from www.api-xpay.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).

Computes a Keccak-256 cryptographic hash of provided input data, payable per-request via USDC on Base using x402.

## Facts

- Endpoint: POST https://www.api-xpay.com/x402/keccak?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x-pay-keccak256-hash-5df4ccd4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eWfCmEHmn8UA5lnH9xWLF

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 x-pay-keccak256-hash-5df4ccd4 -d '<json body>'
```

Example prompt: Hash the string 'Hello, World!' using keccak256 — I need the hex digest for a smart contract verification check.

## When to prefer this

Choose this endpoint when you need a pay-per-use keccak256 hash with no API key setup, especially for blockchain/Ethereum/Solidity use cases such as event topic generation, function selectors, or on-chain fingerprinting. It is ideal for low-frequency hashing needs where a per-call micropayment model (x402/USDC) is preferred over subscription-based alternatives.

## Known failure modes

- Missing required 'input' body field returns validation error
- Invalid bodyType enum value causes request rejection
- Insufficient USDC payment via x402 results in 402 Payment Required response
- Malformed JSON body returns parse error
- Network congestion on Base may delay payment confirmation

## How this service works

Pay-per-request utility APIs powered by x402 using USDC on Base.

## Output

Returns a JSON object containing the keccak256 hex hash string (prefixed with 0x), a success boolean, the algorithm name ('keccak256'), the payment asset ('USDC'), and the network ('base').

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object"
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "hash": "0x1c8aff950685c2ed4bc3174f3472287b56d9517b9c948127319a09a7a36deac8",
  "asset": "USDC",
  "network": "base",
  "success": true,
  "algorithm": "keccak256"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x-pay-keccak256-hash-5df4ccd4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.api-xpay.com](https://www.zero.xyz/host/www.api-xpay.com/llms.txt)