# x402 AI Gateway – Currency Model Endpoint

> x402 AI Gateway – Currency Model Endpoint is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.0002/call, status unknown (last checked 2026-10-16).

Executes a paywalled AI model endpoint for currency-related computations (likely currency conversion or financial model), requiring a micropayment in USDC on Base via x402 before processing.

## Facts

- Endpoint: POST https://api.fastapi.online/f/fx/ang/mdl?utm_source=zero.xyz
- Price: $0.0002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-ai-gateway-currency-model-endpoint-fa1567ca
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hStz4f1vgemS4FDAqcuiU

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-model-endpoint-fa1567ca -d '<json body>'
```

Example prompt: Convert 250 units of my source currency using the x402 AI gateway — pay the $0.0002 USDC micropayment and return the model's computed result.

## When to prefer this

Choose this endpoint when you need a very cheap ($0.0002 USDC), per-call AI inference result for currency-related computations and your agent supports x402 micropayment flows on Base. It is ideal for automated pipelines that need many small, inexpensive AI calls without a subscription or API key, and where the x402 payment protocol is already integrated.

## Known failure modes

- Payment not accepted (402 response if USDC micropayment fails or wallet has insufficient balance)
- Invalid or missing 'amount' field returns a 422 validation error
- Model execution failure returns a 500 server error
- Rate limiting or quota exceeded on the self-hosted inference server
- Network timeout if the self-hosted backend is unavailable

## How this service works

Self-hosted AI API gateway. Expensive endpoints require an x402 micropayment (USDC on Base) before executing.

## Output

An unstructured JSON object containing the AI model's computed output — likely a currency conversion result or financial inference value — returned after the x402 micropayment is validated and the model executes.

## 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-model-endpoint-fa1567ca/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)