# 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 2026-10-12).

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/mop?utm_source=zero.xyz
- Price: $0.0002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-ai-gateway-currency-amount-converter-a2c53e2a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_W0dB__aHlAl6aUbhnq8Yt

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-a2c53e2a -d '<json body>'
```

Example prompt: Convert 250 units of USD to EUR for me — this uses the x402 micropayment gateway so it'll cost a tiny USDC fee per call.

## When to prefer this

Choose this endpoint when you need a pay-per-call, self-hosted currency conversion that integrates natively with the x402 micropayment protocol (USDC on Base). Prefer it in agentic workflows where cost-per-call accountability matters and you want on-chain payment provenance. Not ideal if you need a free or high-volume batch conversion, or if you require guaranteed SLA from a centralized provider.

## Known failure modes

- Payment not fulfilled — x402 micropayment (USDC on Base) not provided or rejected, resulting in a 402 Payment Required response
- Invalid or missing amount field — defaults to 1 if omitted, but malformed input may return an error
- Gateway unavailable — self-hosted infrastructure may be offline or rate-limited
- Unrecognized currency pair — if the endpoint does not support the requested source/target currency combination

## 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 converted currency amount result. The exact fields depend on the gateway's internal logic, but the agent receives the computed conversion output for the given input amount.

## 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-a2c53e2a/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)