# LedgerProof FX Rate Lookup

> LedgerProof FX Rate Lookup is a paid API for AI agents from laen-army-cdp.fly.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns the current exchange rate between two ISO-4217 currencies, with a cryptographic hash receipt and proof-gated payment settled only after delivery.

## Facts

- Endpoint: POST https://laen-army-cdp.fly.dev/sol-06-fx-rate
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ledgerproof-fx-rate-lookup-88b9eda7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TgsHOoNjj_0PCINEPRQK-

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 ledgerproof-fx-rate-lookup-88b9eda7 -d '<json body>'
```

Example prompt: What's the current exchange rate from USD to EUR? I need the rate and the inverse, with a verifiable receipt I can use for reconciliation.

## When to prefer this

Choose this endpoint when you need a verifiable, proof-gated FX rate backed by European Central Bank reference data and want a cryptographic hash receipt for auditing or reconciliation — especially in autonomous agent workflows where trustless payment and delivery verification matter.

## Known failure modes

- Invalid or unsupported ISO-4217 currency code returns a validation error
- Network or upstream ECB data unavailability may cause fetch failures
- Rate date may lag real-time by up to one ECB business day
- Payment not captured if acceptance rule fails — no charge on failed delivery

## How this service works

Proof-gated data services for autonomous agents. Payment is captured only after the deliverable passes a published acceptance rule that can genuinely fail, and every settled call includes a free cryptographic hash receipt that verifies independently.

## Output

A JSON object containing the base currency, quote currency, the spot exchange rate, its inverse, the rate date, and the data source (ECB via frankfurter.dev), plus a free cryptographic hash receipt that can be independently verified.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "base": {
   "type": "string",
   "pattern": "^[A-Za-z]{3}$",
   "description": "ISO-4217 base currency"
  },
  "quote": {
   "type": "string",
   "pattern": "^[A-Za-z]{3}$",
   "description": "ISO-4217 quote currency"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "base": "USD",
  "rate": 0.9213,
  "quote": "EUR",
  "source": "European Central Bank reference rates via frankfurter.dev",
  "inverse": 1.0854,
  "rate_date": "2026-08-19"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ledgerproof-fx-rate-lookup-88b9eda7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from laen-army-cdp.fly.dev](https://www.zero.xyz/host/laen-army-cdp.fly.dev/llms.txt)