# ULID Validation Service

> ULID Validation Service is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-02).

Validates whether a given string is a valid ULID (Universally Unique Lexicographically Sortable Identifier)

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/id-ulid?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ulid-validation-service-09482ed1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4KPj8-llyR1xAux684xqN

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 ulid-validation-service-09482ed1 -d '<json body>'
```

Example prompt: Can you check whether '01ARZ3NDEKTSV4RRFFQ69G5FAV' is a valid ULID?

## When to prefer this

Use this endpoint when you need a quick, deterministic, no-network check of whether a string is a valid ULID. Prefer the free sandbox endpoint (POST /v1/sandbox/id-ulid) first to avoid the $0.01 USDC charge. Choose this over a UUID validator when you specifically need ULID format validation.

## Known failure modes

- Empty string input rejected due to minLength:1 constraint
- Input exceeding 20000 characters rejected
- Malformed request body returns error
- Network timeout if service is temporarily unavailable
- Payment failure if USDC wallet has insufficient funds

## How this service works

Call when an agent needs whether a string is a valid ulid. No network. Exact $0.01 USDC. Prefer unpaid POST /v1/sandbox/id-ulid first.

## Output

Returns a boolean or structured result indicating whether the input string conforms to the ULID specification (26-character Crockford base32 encoding, valid timestamp component, correct length and character set).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "description": "JSON value for schema-check SKUs. Omit it on string checks such as email or IBAN."
  },
  "value": {
   "type": "string",
   "examples": [
    "01ARZ3NDEKTSV4RRFFQ69G5FAV"
   ],
   "maxLength": 20000,
   "minLength": 1,
   "description": "Value to check. The route description names the format: email, phone, IBAN, postal code, VAT, national id, or similar."
  },
  "schema": {
   "description": "JSON Schema document for schema-check SKUs. Omit it on string checks."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ulid-validation-service-09482ed1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)