# 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 2026-09-15).

Resolves a hostname to its DNS A record (IPv4 address) via a paid machine-readable settlement service

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/network/dns.a--a-record
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-dns-a-record-lookup-de428a71
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zh86-9w8b1fpGhwsCqpLz

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-de428a71 -d '<json body>'
```

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

## When to prefer this

Use this endpoint when you need a quick, programmatic DNS A-record lookup and are operating in an x402 micropayment-enabled environment. It is suitable for agents that need to resolve hostnames to IPv4 addresses on demand without managing their own DNS resolver infrastructure. At $0.003 per call it is cost-effective for occasional lookups but may not be ideal for high-volume bulk resolution tasks.

## Known failure modes

- Invalid or malformed hostname input returns an error
- Non-existent domain with no A record may return empty or error response
- Network timeout if upstream DNS resolver is unreachable
- Payment failure via x402 prevents the request from being processed
- Domain has only AAAA (IPv6) records and no A record, resulting in empty result

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the resolved IPv4 address(es) and associated DNS A record data for the queried hostname, such as IP address values and potentially TTL or record metadata.

## 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-de428a71/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)