# Liminal Spot Prices – FX Rate

> Liminal Spot Prices – FX Rate is a paid API for AI agents from x402-spot-prices.hsharmanov02.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-02).

Returns live fiat currency exchange rate snapshots (e.g. USD to EUR) sourced from open.er-api.com, paid per-request via x402 at $0.01 USDC.

## Facts

- Endpoint: GET https://x402-spot-prices.hsharmanov02.workers.dev/fx?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/liminal-spot-prices-fx-rate-3211d15a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OUuwH8oDek5HXQPCs8WGS

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 liminal-spot-prices-fx-rate-3211d15a
```

Example prompt: What's the live spot exchange rate from USD to EUR right now? I need the current rate and its inverse.

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-use real-time fiat FX spot rate without a subscription, especially in x402-enabled agent pipelines on EVM-compatible chains or Solana. It is ideal for cost-sensitive agents that only occasionally need currency rates and want to avoid monthly API key commitments.

## Known failure modes

- HTTP 402 returned with base64 PAYMENT-REQUIRED header if no payment signature is provided — must retry with PAYMENT-SIGNATURE header
- Invalid or unsupported currency codes may return an error or empty response
- Rate staleness if upstream open.er-api.com data is delayed
- Network errors from the Cloudflare Worker host

## How this service works

Live crypto spot-price snapshots (USD) and fiat FX spot rates. Pay-per-request via x402 v2: $0.01 USDC on Base, Monad, Arbitrum, Optimism, Polygon, Avalanche or Solana (eip155:8453), Monad (eip155:143), Arbitrum (eip155:42161), Optimism (eip155:10), Polygon (eip155:137), Avalanche (eip155:43114) or Solana, scheme exact (EIP-3009). Unpaid calls return HTTP 402 with a base64 PAYMENT-REQUIRED header; retry with a PAYMENT-SIGNATURE header.

## Output

A JSON object containing the source currency (from), target currency (to), the current spot exchange rate (rate), the inverse rate (inverse_rate), a Unix timestamp of when the rate was recorded (as_of), the data source (open.er-api.com), and the service identifier (fx-rate).

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "to": "EUR",
  "from": "USD",
  "rate": 0.9214,
  "as_of": 1759099200,
  "source": "open.er-api.com",
  "service": "fx-rate",
  "inverse_rate": 1.0853
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/liminal-spot-prices-fx-rate-3211d15a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-spot-prices.hsharmanov02.workers.dev](https://www.zero.xyz/host/x402-spot-prices.hsharmanov02.workers.dev/llms.txt)