# FX Pulse – Stablecoin & Fiat FX Reference Rate (Single Pair)

> FX Pulse – Stablecoin & Fiat FX Reference Rate (Single Pair) is a paid API for AI agents from fx-pulse-chi.vercel.app, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-16).

Returns the current exchange rate between a source fiat currency or stablecoin and a target fiat currency or stablecoin.

## Facts

- Endpoint: GET https://fx-pulse-chi.vercel.app/api/rate?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fx-pulse-stablecoin-fiat-fx-reference-rate-single-pair-3a4b08ed
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rKuFJHz02vvkUvCIlvq50

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 fx-pulse-stablecoin-fiat-fx-reference-rate-single-pair-3a4b08ed
```

Example prompt: What's the current exchange rate from USDC to EUR? I need the FX Pulse reference rate so I can price an invoice.

## When to prefer this

Choose this endpoint when you need a real-time or near-real-time reference exchange rate between fiat currencies and/or major stablecoins (USDC, EURC, USDT) and want a pay-per-call pricing model with no subscription commitment. It is particularly well-suited for AI agents that need to price stablecoin transactions, invoice amounts, or cross-border payments on demand.

## Known failure modes

- Unsupported currency ticker — returns an error if 'from' or 'to' is not a recognized ISO-4217 code or supported stablecoin ticker
- Missing required parameters — omitting 'from' or 'to' will likely return a 400-level error
- Payment failure — if the x402 USDC micropayment on Base is not processed correctly, the request will be rejected
- Rate unavailability — if the underlying FX data source is temporarily unavailable, the endpoint may return a 5xx error

## How this service works

Single-pair rate, amount conversion, and batch FX rates for fiat currencies and major stablecoins (USDC, EURC, USDT...). Pay-per-call in USDC via x402 on Base.

## Output

Returns a JSON object containing the source currency ('from'), target currency ('to'), the exchange rate as a decimal number ('rate'), and the date of the rate ('date'). Example: {"from":"USDC","to":"EUR","rate":0.92,"date":"2026-09-19"}.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "description": "Target currency (ISO-4217) or stablecoin ticker."
  },
  "from": {
   "type": "string",
   "description": "Source currency (ISO-4217) or stablecoin ticker (USDC, USDT, EURC...)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "to": "EUR",
  "date": "2026-09-19",
  "from": "USDC",
  "rate": 0.92
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fx-pulse-stablecoin-fiat-fx-reference-rate-single-pair-3a4b08ed/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fx-pulse-chi.vercel.app](https://www.zero.xyz/host/fx-pulse-chi.vercel.app/llms.txt)