# Base Sentinel Hash API

> Base Sentinel Hash API is a paid API for AI agents from base-sentinel-production.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Computes a cryptographic hash (SHA-256, SHA-512, SHA-1, or MD5) of a given text string, returning results as both hex and base64 encodings.

## Facts

- Endpoint: POST https://base-sentinel-production.up.railway.app/api/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/base-sentinel-hash-api-30ac899e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vE24-r4IC7srO75JiVZGp

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 base-sentinel-hash-api-30ac899e -d '<json body>'
```

Example prompt: Can you compute the SHA-256 hash of the text 'Hello, world!' and give me both the hex and base64 versions?

## When to prefer this

Choose this endpoint when you need a quick, pure-computation hash of a text string with no infrastructure setup, want dual encoding (hex + base64) in one call, and need support for multiple algorithms (SHA-256, SHA-512, SHA-1, MD5). Ideal for serverless agents that need deterministic IDs, content fingerprints, or lightweight integrity checks without importing a local crypto library.

## Known failure modes

- Text exceeds 100KB limit — request rejected
- Invalid algorithm name supplied — may return an error or default to sha256
- Empty text input — may return hash of empty string or an error
- Malformed JSON body — HTTP 400 bad request
- Service unavailable (Railway deployment down) — HTTP 5xx

## How this service works

Cryptographic hash of a text string - sha256 (default), sha512, sha1 or md5 - returned as hex and base64. Use it for content fingerprints, integrity checks and deterministic ids; pure computation, instant.

## Output

Returns a JSON object containing both a hex-encoded and a base64-encoded cryptographic hash of the input text, computed using the specified algorithm (defaults to SHA-256 if not specified).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "algo": {
   "type": "string",
   "description": "sha256 | sha512 | sha1 | md5"
  },
  "text": {
   "type": "string",
   "description": "Text to hash (max 100KB)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-sentinel-hash-api-30ac899e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from base-sentinel-production.up.railway.app](https://www.zero.xyz/host/base-sentinel-production.up.railway.app/llms.txt)