About Cambiaro

Cambiaro is a currency converter for people and AI agents. It converts between 165 world currencies using live and historical exchange rates published by the European Central Bank, shows how a pair has moved over time, and installs to a phone or desktop as an offline-capable app.

What makes it unusual is that every action in the interface is also a typed tool an AI agent can call directly, through the emerging WebMCP standard — so an agent operates the converter the same way a person does, and you can watch it happen.

What you can do with it

  • Convert an amount between any two of 165 currencies, updated as you type.
  • Look up what a rate was on a specific past date, back to 4 January 1999.
  • Chart how a currency pair has moved over the last 7, 30 or 90 days.
  • Install it to your home screen and keep converting when you are offline.
  • Let an AI agent run any of those actions through seven WebMCP tools.

Agent tools

Cambiaro registers these tools on document.modelContext, each with its own JSON Schema and typed result:

convertCurrency
Convert an amount between two currencies, optionally as of a past date.
swapCurrencies
Swap the two currencies and reconvert.
setBaseCurrency
Change the currency being converted from.
setQuoteCurrency
Change the currency being converted to.
listCurrencies
List or filter the supported currencies.
getHistoricalRate
Read the rate for a pair on a given day.
getRateTimeSeries
Read a range of rates and draw the chart.

Frequently asked questions

Where do Cambiaro's exchange rates come from?

Rates are European Central Bank reference rates, retrieved through the Frankfurter API. The ECB publishes them once per working day at around 16:00 CET, so a rate is dated to the day it was published rather than the moment you look at it.

How far back do the historical rates go?

Back to 4 January 1999 for most currencies, which is when the euro reference rates began. Currencies added later start from their own first published date, and the date picker limits you to the range each pair actually covers.

Can an AI agent use Cambiaro?

Yes. Cambiaro registers seven WebMCP tools on document.modelContext. An agent can call them directly and receive typed results, with no DOM scraping. Every call is reflected in the visible interface and logged in the Agent Activity panel.

Can I install Cambiaro and use it offline?

Yes. It is a Progressive Web App, so it installs to a phone home screen or desktop. Rate responses are cached, so opening it without a network shows the last known rates clearly labelled with the date they were published.

Does Cambiaro support cryptocurrency?

No. It covers the 165 fiat currencies tracked by the European Central Bank. Bitcoin and other cryptocurrencies are out of scope.

How much does Cambiaro cost?

Nothing. It is free and runs entirely in your browser.

Rates from the Frankfurter API, sourced from European Central Bank reference rates. Cambiaro is not affiliated with the ECB. Rates are reference data for information, not a dealing quote.