# StableDomains Domain Availability Check

> StableDomains Domain Availability Check is a paid API for AI agents from stabledomains.dev, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Check whether a domain name is available for registration and retrieve its pricing information

## Facts

- Endpoint: POST https://stabledomains.dev/api/check
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 13
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stabledomains-51de3ce2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9dKBdWoa8WE-mWYa663qv

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 stabledomains-51de3ce2 -d '<json body>'
```

Example prompt: Can you check if 'coolstartup.dev' is available to register on StableDomains, and tell me how much it would cost?

## When to prefer this

Use this endpoint when you need to check domain availability and pricing before committing to a registration on StableDomains, especially when paying with USDC via x402/MPP protocol. Prefer this over manual WHOIS lookups when operating in a crypto-native or agent-automated workflow.

## Known failure modes

- Invalid domain name format returns an error response
- Domain TLD not supported returns unavailable or error
- Network timeout or service unavailability returns 5xx error
- Missing or invalid x402/MPP authentication returns 401/402

## How this service works

Check availability and pricing. Auth: x402/MPP.

## Output

Returns whether the specified domain name is available for registration and, if so, the price in USDC to register it.

## Example request

```json
{
 "domain": "testexample.dev"
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "domain": {
   "type": "string",
   "description": "Full domain (e.g. \"example.com\"). Supported TLDs (28): .ai, .app, .biz, .cloud, .co, .com, .dev, .email, .info, .io, .link, .live, .me, .mobi, .name, .net, .online, .org, .page, .pro, .shop, .site, .store, .studio, .tech, .tv, .uk, .xyz."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stabledomains-51de3ce2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stabledomains.dev](https://www.zero.xyz/host/stabledomains.dev/llms.txt)