# PennyRail DNS A Record Lookup

> PennyRail DNS A Record Lookup is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Resolves a domain name to its DNS A record (IPv4 address) via a paid API endpoint

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/f/dns.a
- 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/pennyrail-dns-a-record-lookup-a78765c2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_s-Y--VTTy1kdLFVCRSO5Z

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 pennyrail-dns-a-record-lookup-a78765c2 -d '<json body>'
```

Example prompt: Can you look up the DNS A record for github.com and tell me what IPv4 address it resolves to?

## When to prefer this

Choose this endpoint when you need a pay-per-query DNS A record lookup without provisioning your own DNS resolver infrastructure, especially in agent workflows where micro-payment via x402/USDC is already supported. It is a lightweight, per-call option for resolving individual hostnames to IPv4 addresses without API keys or subscriptions.

## Known failure modes

- Domain does not exist or has no A record — result may be empty or null
- Invalid domain string input — malformed hostname
- Network or DNS resolution failure — upstream DNS timeout
- Payment failure — x402 payment not accepted, endpoint returns 402
- Rate limiting or service unavailability on the Vercel deployment

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the operation name (e.g. 'dns.a') and a result field with the resolved IPv4 address or addresses for the queried domain.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "string",
   "description": "domain string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "operation",
  "result"
 ],
 "properties": {
  "result": {},
  "operation": {
   "type": "string"
  }
 },
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-dns-a-record-lookup-a78765c2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pennyrail.vercel.app](https://www.zero.xyz/host/pennyrail.vercel.app/llms.txt)