# Agentshelf Loose Semver Validator

> Agentshelf Loose Semver Validator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Validates whether a given string is a valid semantic version (semver) optionally prefixed with a leading 'v'

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-semver-loose?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-loose-semver-validator-968b7391
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BWadpvbKcTWdDJWMXMfj9

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 agentshelf-loose-semver-validator-968b7391 -d '<json body>'
```

Example prompt: Can you check whether the string 'v1.4.2-beta.1' is a valid loose semver version (with an optional leading v)?

## When to prefer this

Use this endpoint when you need a deterministic, no-LLM semver validation that accepts an optional leading 'v' prefix (loose semver). Prefer the free sandbox endpoint /v1/sandbox/check-semver-loose first; only fall back to this paid endpoint when the sandbox is unavailable or a verified paid response is required. Choose this over regex-based local validation when you need a reliable, hosted check without implementing semver parsing yourself.

## Known failure modes

- Empty string input returns an error (minLength is 1)
- String exceeding 20000 characters is rejected
- Malformed request body returns a 4xx error
- Payment not settled or x402 payment rejected results in a 402 response

## How this service works

Call when an agent needs whether a string is semver with an optional leading v. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/check-semver-loose first.

## Output

Returns a result indicating whether the input string is a valid loose semver version (with optional leading 'v'), along with any relevant parsing details or a boolean validity flag.

## 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": [
    "v1.2.3"
   ],
   "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/agentshelf-loose-semver-validator-968b7391/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)