# 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 2026-10-11).

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

## Facts

- Endpoint: POST https://api.fastapi.online/f/fx/ang/lrd?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-conversion-endpoint-3df85f1e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yH_jK0KAVZIlhhMYKGiI3

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-3df85f1e -d '<json body>'
```

Example prompt: Convert 250 units of my source currency using the x402-gated fastapi.online conversion endpoint — pay the $0.0002 USDC micropayment and return the result.

## When to prefer this

Choose this endpoint when you need a pay-per-call, self-hosted currency conversion that is gated by an x402 USDC micropayment on Base, particularly when minimizing per-call cost ($0.0002 USDC) and avoiding subscription-based FX APIs. Suitable for agents with x402 payment capability that need lightweight, on-demand currency conversion without API key management.

## Known failure modes

- Payment not provided or insufficient — endpoint returns HTTP 402 requiring x402 USDC micropayment on Base
- Invalid or missing amount field — endpoint may return validation error
- Network or gateway error on the self-hosted server — returns 5xx
- Unsupported currency pair — may return empty or error response
- Amount of 0 or negative — may produce unexpected result

## 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 value or exchange result for the specified amount. Exact output fields are unspecified in the schema but expected to include the converted 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-3df85f1e/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)