Wasp

Wasp builds an open-source full-stack TypeScript framework for developers creating SaaS products, internal tools and other web applications. It connects React, Node.js and Prisma with authentication, background jobs, email, typed client-server calls and deployment tooling. Developers specify application features and write their business logic in the underlying stack, then deploy to their chosen infrastructure. Its Open SaaS starter adds payments, an admin dashboard and email functionality, providing a starting point for subscription software.

Co-founders Matija Šošić, CEO, and Martin Šošić, CTO, took Wasp through Y Combinator in 2021. Its engineering approach separates an explicit application specification from implementation code: the compiler combines that specification with frontend, backend and database code to produce a deployable app. In 2026, Wasp replaced its custom specification language with TypeScript Spec, retaining the compiler approach while enabling standard editor support and programmable configuration. The specification also gives developers and AI coding tools a central overview of application structure.

At the end of 2025, Wasp reported eight full-time workers, 4,669 Discord members and more than 13,000 GitHub stars for Open SaaS. By May 2026, the company had raised over $5 million in cumulative funding.