# PennyRail URL Resolve – Relative URL Resolution

> PennyRail URL Resolve – Relative URL Resolution 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 relative URL against a base URL to produce an absolute URL

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/url.resolve--resolve-relative-url
- 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-url-resolve-relative-url-resolution-4129b71a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NmEb1QLNN7h3AVY-LJW0X

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-url-resolve-relative-url-resolution-4129b71a -d '<json body>'
```

Example prompt: Can you resolve the relative URL '../images/logo.png' against the base 'https://example.com/docs/guide/' to get the full absolute URL?

## When to prefer this

Use this endpoint when you need a lightweight, pay-per-call URL resolution service without standing up your own URL parsing infrastructure, particularly in agent workflows where relative hrefs need to be absolutized on the fly after scraping or parsing HTML.

## Known failure modes

- Invalid or malformed base URL returns an error
- Relative URL that cannot be resolved against the base (e.g. protocol-relative conflicts)
- Missing required input fields returns validation error
- Payment not processed results in 402 response before computation

## How this service works

Machine-readable settlement service

## Output

Returns an absolute URL string computed by resolving the provided relative URL against the given base URL, following standard URL resolution rules (RFC 3986).

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-url-resolve-relative-url-resolution-4129b71a/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)