# Hash Digest

> Hash Digest is a paid API for AI agents from x402-echo-service.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Compute cryptographic hash digests (SHA-256, SHA-512, or Keccak-256) of an input string and return hex-encoded results.

## Facts

- Endpoint: POST https://x402-echo-service.onrender.com/hash
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hash-digest-54bf16a2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_skdEyiyBf9DaYV3NAietQ

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 hash-digest-54bf16a2 -d '<json body>'
```

Example prompt: Hash the string 'hello world' using both sha256 and keccak256 and give me the hex digests.

## When to prefer this

Choose this endpoint when you need a quick, deterministic cryptographic hash of a string without setting up local crypto libraries — especially useful in agent pipelines where you need keccak256 (Ethereum-compatible hashing) alongside standard SHA algorithms. Ideal for verifying data integrity, generating content fingerprints, or producing Ethereum-compatible hashes in a serverless context. Prefer this over local computation when operating in environments where native crypto is unavailable or for multi-algorithm comparisons in a single call.

## Known failure modes

- Empty or missing input string returns a validation error
- Unsupported algorithm name (anything other than sha256, sha512, keccak256) returns an error
- Input exceeding 65536 characters is rejected
- Malformed JSON body returns a 400 error
- Service unavailability on Render cold-start may cause occasional timeouts

## How this service works

Compute cryptographic digests of a string. POST {"input":"...","algorithms":["sha256"]} and receive one hex digest per requested algorithm. Supports sha256, sha512 and keccak256. Deterministic, no storage, no upstream calls.

## Output

Returns an object mapping each requested algorithm name to its hex-encoded digest of the input string. For example: {"sha256": "b94d27b9...", "keccak256": "4e03657a..."}. Results are deterministic and purely computed — no state is stored and no external calls are made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 1
  },
  "algorithms": {
   "type": "array",
   "items": {
    "enum": [
     "sha256",
     "sha512",
     "keccak256"
    ]
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hash-digest-54bf16a2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-echo-service.onrender.com](https://www.zero.xyz/host/x402-echo-service.onrender.com/llms.txt)