# Keccak-256 Hash API

> Keccak-256 Hash API is a paid API for AI agents from api.api-agent-ia.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-26).

Computes the Keccak-256 cryptographic hash of a given text string and returns the hex-encoded digest

## Facts

- Endpoint: GET https://api.api-agent-ia.ch/hash-keccak?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-26
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/keccak-256-hash-api-fd6da670
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3rrCzTxwqD6TARipxCUjE

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 keccak-256-hash-api-fd6da670
```

Example prompt: Can you compute the Keccak-256 hash of the text 'hello world'?

## When to prefer this

Choose this endpoint when you need an Ethereum/Solidity-compatible Keccak-256 hash (not SHA-3) of a text string — particularly useful for generating EVM event signatures, function selectors, or verifiable digests in web3 workflows. It is a simple, pay-per-call API requiring no setup, ideal for agents that need one-off hashing without integrating a cryptographic library.

## Known failure modes

- Missing required 'text' query parameter returns an error response
- Empty string input may return a valid hash of the empty string (not an error)
- Very long text strings may be rejected or truncated
- Network errors or service downtime return non-200 status codes
- Invalid UTF-8 or special characters in text may cause unexpected results

## How this service works

Need a function selector or an event topic? Returns the Keccak-256 hash of a text string, in 0x hex ($0.001 per call).

## Output

A JSON object containing the original input text and its Keccak-256 hash as a 0x-prefixed hex string (e.g. {"hash": "0x1c8aff...", "text": "hello"}).

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "text"
     ],
     "properties": {
      "text": {
       "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": "0xa9059cbb2ab09eb219583f4a59a5d0623ade346d962bcd4e46b11da047c9049b",
  "text": "transfer(address,uint256)"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/keccak-256-hash-api-fd6da670/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.api-agent-ia.ch](https://www.zero.xyz/host/api.api-agent-ia.ch/llms.txt)