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Madhushan
Madhushan

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live-currency-rates: One fluent API, three FX providers (no API key required to start)

#javascript #typescript #currency #api

Picking an FX data provider is one of those decisions you don't want to couple your code to. ECB data is free but only ~30 currencies. fawazahmed0/currency-api is free and covers crypto, but it's CDN-based. AllRatesToday gives you real-time Reuters data but needs a key. Each has different endpoints, shapes, and auth.

live-currency-rates is a tiny wrapper that hides all of that behind a fluent API. Write your code once; swap providers with one line when requirements change.

The API you actually write 

import { Convert } from 'live-currency-rates';

const result = await Convert(100).from('USD').to('EUR');
console.log(result.amount); // 92.45
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That's it. No setup needed to start — defaults to the free Frankfurter provider (ECB data, no key, no signup).

Install 

npm install live-currency-rates
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Zero dependencies. TypeScript types included.

Three providers, one interface

Provider Key? Currencies Source Notes
frankfurter no ~30 European Central Bank Default. Daily updates.
fawaz no 200+ fawazahmed0/currency-api Includes crypto. CDN-hosted.
allrates yes 160+ AllRatesToday (Reuters) Real-time mid-market rates.

Pick one with setup():

import { setup, Convert } from 'live-currency-rates';

// Free, no key — 200+ currencies including crypto
setup({ provider: 'fawaz' });

// AllRatesToday — real-time Reuters rates, free key at allratestoday.com/register
setup({ apiKey: 'art_live_...' });
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Your existing Convert(...) calls don't change. That's the point.

Core API

Convert(amount).from(...).to(...) 

const result = await Convert(250).from('GBP').to('JPY');
console.log(`250 GBP = ${result.amount} JPY`);
console.log(`Rate: ${result.rate}`);
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Returns { amount, rate, from, to, originalAmount }.

Rate('XXX').to('YYY') 

import { Rate } from 'live-currency-rates';

const { rate } = await Rate('USD').to('EUR');
console.log(`1 USD = ${rate} EUR`);
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Rates('XXX', ['YYY', 'ZZZ'])

One round-trip, multiple pairs:

import { Rates } from 'live-currency-rates';

const rates = await Rates('USD', ['EUR', 'GBP', 'JPY']);
// { EUR: 0.92, GBP: 0.78, JPY: 149.5 }
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Omit the target list to get every available rate for that base.

Why a wrapper?

Three reasons it earns its keep:

  1. Start free, upgrade later. Ship the MVP with Frankfurter. When you hit a currency Frankfurter doesn't cover, flip to fawaz or allrates without touching call sites.
  2. Test without hitting production. Point tests at Frankfurter; point prod at AllRatesToday. Same code.
  3. Provider lock-in is costly. Every provider has different endpoint shapes. A fluent wrapper means a future provider migration is one file change, not a rewrite.

When you outgrow the wrapper

The wrapper optimizes for "I don't care which provider yet." If you've settled on a provider and need its full feature set, drop to the native client:

  • AllRatesToday only? Use @allratestoday/sdk — full API: historicals, time-series, preset periods.
  • Just want a one-liner + CLI? Use fx-rates.
  • Need cashify-compatible sync conversion? Use moneyify.

Next steps

Which provider did you land on, and why? Comments open.

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