# 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, $0.003/call, status unknown (last checked 2026-09-16).

Performs a DNS A record lookup for a given hostname, returning the resolved IPv4 address(es)

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/network/dns.a--dns-a-lookup
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-dns-a-record-lookup-4519a7bd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JJ-9MWC7Xw3Lyh50SDzNH

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-4519a7bd -d '<json body>'
```

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

## When to prefer this

Use this endpoint when you need a quick, pay-per-call DNS A record resolution without managing your own DNS resolver infrastructure. Ideal for AI agents that need to enrich hostnames with IP data on demand, verify DNS propagation, or perform lightweight infrastructure checks without a full DNS client library. Prefer this over general-purpose DNS APIs when operating in a micropayment-native (x402) workflow.

## Known failure modes

- Non-existent domain returns an error or empty result (NXDOMAIN)
- Malformed hostname input may result in a validation error
- Domains with no A record (e.g. only AAAA or CNAME) may return empty or null
- Network or upstream DNS resolver timeouts may cause failures
- Rate limiting or payment failure may result in a 402 response

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the resolved IPv4 address(es) associated with the queried hostname's DNS A record, including any relevant metadata about the resolution result.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-dns-a-record-lookup-4519a7bd/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)