# x402 AI Gateway – Currency Amount Converter

> x402 AI Gateway – Currency Amount Converter is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.0002/call, status unknown (last checked 2026-10-10).

Converts a specified amount of a source currency, gated behind an x402 USDC micropayment on Base before execution.

## Facts

- Endpoint: POST https://api.fastapi.online/f/fx/ang/lbp?utm_source=zero.xyz
- Price: $0.0002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-ai-gateway-currency-amount-converter-e15d533a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eec_bEjOyYK6hPlE2lWrJ

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 x402-ai-gateway-currency-amount-converter-e15d533a -d '<json body>'
```

Example prompt: Convert 250 units of the source currency for me — I need the converted amount back, and I'm okay with the $0.0002 USDC micropayment to unlock the result.

## When to prefer this

Prefer this endpoint when you need a lightweight, low-cost ($0.0002 USDC) currency conversion that is gated by an x402 micropayment and you are operating in an agent or wallet environment already set up to handle x402 payment flows on Base. Not recommended when you need free, unlimited, or enterprise-grade FX data with guaranteed SLAs.

## Known failure modes

- Payment not received or invalid x402 micropayment — endpoint returns 402 Payment Required before executing
- Invalid or missing amount parameter — may return a 422 validation error
- Unsupported or unspecified currency — may return an error or unexpected result
- Server unavailable — self-hosted infrastructure may have higher downtime risk than managed APIs
- Ambiguous input schema — 'amount' alone without an explicit source/target currency may yield unexpected defaults

## How this service works

Self-hosted AI API gateway. Expensive endpoints require an x402 micropayment (USDC on Base) before executing.

## Output

Returns a JSON object containing the result of the currency conversion for the given amount; exact fields depend on the server implementation but typically include the converted value and possibly exchange rate metadata.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "amount": {
   "type": "number",
   "description": "Amount of the source currency to convert (default 1)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-ai-gateway-currency-amount-converter-e15d533a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fastapi.online](https://www.zero.xyz/host/api.fastapi.online/llms.txt)