# 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 2026-10-11).

Converts a specified amount of a source currency, returning the converted value, via a micropayment-gated AI inference endpoint.

## Facts

- Endpoint: POST https://api.fastapi.online/f/fx/aoa/ttd?utm_source=zero.xyz
- Price: $0.0002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-ai-gateway-currency-amount-converter-7cc82b33
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IgMh5rqRZtqr0jyaSEB5T

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-7cc82b33 -d '<json body>'
```

Example prompt: Convert 100 units of my source currency using the x402 AI gateway — just pass the amount and give me back the converted result.

## When to prefer this

Choose this endpoint when you need a micropayment-gated currency conversion computation hosted on a self-hosted AI inference gateway (fastapi.online), especially in workflows already using the x402 payment protocol on Base/USDC. It is best suited for agents that manage x402 payments natively and need a low-cost ($0.0002 USDC) per-call conversion without relying on traditional API-key-gated FX services.

## Known failure modes

- Payment not provided or invalid x402 micropayment — returns HTTP 402 Payment Required
- Amount field missing or non-numeric — returns validation error
- Source or target currency not supported — may return empty or error object
- Downstream AI inference service unavailable — returns 5xx error
- Malformed request body — returns 422 Unprocessable Entity

## 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 of the source currency. The exact fields depend on the endpoint's implementation, but typically include the converted value and possibly the exchange rate or currency pair details.

## 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-7cc82b33/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)