# 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 currency using an AI-powered self-hosted gateway, requiring a micropayment (USDC on Base) via x402 protocol before execution.

## Facts

- Endpoint: POST https://api.fastapi.online/f/fx/ang/mad?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-ce134f50
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eUk3LPfvKTg-HpAVHHWxQ

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-ce134f50 -d '<json body>'
```

Example prompt: Convert 250 units of the source currency for me using the x402 AI gateway — I need the converted amount back right away.

## When to prefer this

Choose this endpoint when you need a pay-per-call, ultra-low-cost ($0.0002 USDC) currency conversion via an x402-compatible micropayment workflow, especially when integrating with agents that support the x402 payment protocol on Base and want to avoid subscription-based APIs.

## Known failure modes

- Payment not included or insufficient USDC micropayment returns 402 Payment Required
- Invalid or missing 'amount' field returns validation error
- Upstream AI inference service unavailable returns 503 or 500
- Malformed request body returns 422 Unprocessable Entity
- Network timeout if self-hosted backend is under load

## 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 conversion result for the specified amount; exact response fields are not strictly defined but typically include the converted value or equivalent output.

## 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-ce134f50/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)