# x402 AI Gateway — Currency Conversion Endpoint

> x402 AI Gateway — Currency Conversion Endpoint 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 from one currency to another, requiring a micropayment in USDC on Base before execution.

## Facts

- Endpoint: POST https://api.fastapi.online/f/fx/ang/hrk?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-conversion-endpoint-87c65b3a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ic6bBbJ38XmfnjgqgfmUC

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-conversion-endpoint-87c65b3a -d '<json body>'
```

Example prompt: Convert 250 US dollars to Japanese yen using the x402 AI gateway and tell me the result.

## When to prefer this

Choose this endpoint when you need a pay-per-call currency conversion integrated into an x402-compatible agent workflow on Base/USDC, and want to avoid subscription-based FX APIs. Particularly useful for agents that only occasionally need conversions and want to pay fractions of a cent per call rather than maintaining API key subscriptions.

## Known failure modes

- Payment failure: x402 micropayment not completed or insufficient USDC balance, resulting in 402 Payment Required response
- Invalid currency codes: unrecognized or unsupported currency pair returns an error
- Amount out of range: zero or negative amount may cause validation error
- Network/gateway unavailability: self-hosted service may be intermittently offline
- Missing required parameters: omitting amount or currency codes may result in a 422 Unprocessable Entity error

## 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 and likely the applicable exchange rate or conversion details for the requested currency pair and 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-conversion-endpoint-87c65b3a/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)