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x402 AI Gateway – Currency Conversion
x402
x402 AI Gateway – Currency Conversion is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.0002/call, status down (last checked 2026-10-12).
Converts a specified amount of a source currency, gated by an x402 USDC micropayment on Base before execution.
Price / call$0.0002
Success—
StatusDown
How this service works
Self-hosted AI API gateway. Expensive endpoints require an x402 micropayment (USDC on Base) before executing.
Output
A JSON object containing the result of the currency conversion computation, returned after the x402 USDC micropayment on Base is settled. Exact fields depend on server implementation but typically include the converted amount and possibly the exchange rate used.
Example use cases
Quick foreign exchange rate lookup
“Convert 500 of the source currency for me using the x402 gateway — I need the converted value right away.”
Automated per-call currency conversion in a pipeline
“I'm building a workflow that needs to convert amounts on the fly; use the x402 micropayment gateway to convert 1 unit of source currency and return the result.”
Testing x402 micropayment-gated API
“Run a test conversion of 1 unit through the x402 AI gateway so I can verify the USDC payment flow works correctly.”
Technical details
Endpoint
POSThttps://api.fastapi.online/f/fx/aoa/xsu?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a lightweight, pay-per-call currency conversion without subscription overhead, and you already have an x402-compatible USDC wallet on Base. It is ideal for low-frequency automated agents that want to avoid API key management and prefer crypto micropayments. Not ideal if you need high-volume batch conversions or guaranteed SLAs from a commercial FX provider.
Side effects
- Payment not provided or rejected — HTTP 402 returned, requiring a valid USDC micropayment on Base before proceeding
- Invalid or missing amount field — server may return a 422 validation error
- Unsupported currency pair — endpoint may return an error if the source/target currency is not supported
- Server unavailable — self-hosted infrastructure may experience downtime or rate limiting
- Micropayment facilitator network issues — Base network congestion could delay or fail payment settlement
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| amount | number | Amount of the source currency to convert (default 1) |
Output
Schema · Response
{
"type": "object"
}Tags
x402
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