Transak is a developer integration toolkit that simplifies the process of onboarding users to buy and sell crypto in blockchain applications. It offers API-driven fiat payment methods and handles KYC, compliance, and customer support, making it easy for developers to enable fiat-crypto on- and off-ramping. With Transak, mainstream users can access web3 apps more easily, and developers can increase their revenue while customizing the integration according to their needs.