An external API is a third-party service which provides balances and/or transaction data, that can be used in other applications. API stands for "Application Programming Interface".
Using external APIs, you can develop your own web services to expose your financial data, without needing to provide CryptFolio with any of your own credentials.
For example, you could specify an external API "https://example.com/my_btc_balance", which returns the number "1.0" - signifying that you want to add 1.0 BTC to your portfolio.
The technical specifications for the range of supported External API formats is now available.
You can add an External API to your portfolio by clicking on the External API button when configuring it.