Quint

Quint is an open-source specification language built for modeling and verifying distributed systems, protocols, and smart contracts. It combines an approachable, TypeScript-inspired syntax with powerful formal verification capabilities, making it easier for engineers to catch bugs before they reach production. Quint is developed by Informal Systems and draws on decades of experience with the TLA+ specification language, offering a more ergonomic alternative for modern software teams.

• Formal Specification — Write precise, executable models of your distributed system or protocol using a readable, TypeScript-like syntax.
• Model Checking — Automatically explore all possible system states to detect bugs, race conditions, and invariant violations before deployment.
• Simulation & Testing — Run randomized simulations of your specifications to quickly find counterexamples and validate system behavior.
• REPL (Interactive Shell) — Experiment with specifications interactively using the built-in REPL for rapid prototyping and exploration.
• VS Code Extension — Get syntax highlighting, type checking, and inline feedback directly in your editor via the official VS Code extension.
• TLA+ Transpilation — Transpile Quint specifications to TLA+ for use with the TLC model checker and other TLA+ tooling.
• Type System — Leverage a strong static type system to catch errors early and improve specification clarity.
• Open Source — Freely available on GitHub under an open-source license, with active community development and contributions.

To get started, install the Quint CLI via npm, write a .qnt specification file, and use the quint run or quint verify commands to simulate or model-check your system. The VS Code extension provides an enhanced editing experience with real-time feedback.