After over 12 years of building and refining Calcapp, a formula-driven app creator, I’m excited to announce fxEngine - a statically-typed formula engine now available for developers.
What is fxEngine?
fxEngine is a comprehensive formula engine that brings Excel-like expressions to your applications, with the added benefit of static type checking. It’s the same engine that powers Calcapp, battle-tested with thousands of users.
What’s Included
fxEngine offers multiple components:
- REST API Service: Compile, validate, and evaluate formulas via HTTP
- Java Library: Integrate formula compilation and validation directly into your JVM applications
- JavaScript Runtime: Evaluate compiled formulas on the client or server (via GraalVM)
- CodeMirror Editor: A ready-to-use formula editor with autocomplete and inline documentation
Why Static Typing Matters
Unlike traditional formula engines that only discover errors at runtime, fxEngine validates your formulas at compile time. This means:
- Catch type mismatches before deployment
- Better autocomplete and developer experience
- Confidence that formulas will work in production
Get Started
Head over to our Quickstart guide to start using fxEngine in your project.
More posts coming soon about the technical architecture, migration from Calcapp, and deep dives into the formula language.