Unrust

Unrust is a coding diagnostic and practice service for JavaScript, TypeScript, and Python. Its diagnostic is unassisted: it does not use AI or autocomplete while a learner is answering. The exercises focus on recall, debugging, tracing, language idioms, identifying flaws, and reviewing code produced by AI. This gives developers a way to practice reading and reasoning about code, including work that may have been drafted with an AI tool, without asking an AI system to solve the diagnostic for them. Unrust is a developer tool for learning and assessment; it is not an AI agent or code generator.
The diagnostic emphasizes understanding what code does, finding issues, explaining a debugging path, and recognizing idiomatic patterns. Tracing tasks ask the learner to follow code behavior step by step. Debugging and flaw-finding tasks encourage close reading and careful reasoning. Code review prompts can include AI-written code so that a learner can practice checking its behavior rather than assuming generated output is correct. The user brings their own reasoning to the diagnostic, and the work focuses on their ability to recall concepts, trace execution, identify errors, and explain why an implementation may be flawed.
Unrust includes free diagnostic and account features, with optional paid practice for people who want additional work. Its language focus is JavaScript, TypeScript, and Python. It is designed for developers who want to check and strengthen practical coding skills in those languages. It can fit independent study or regular skills practice, especially for people who want to improve their confidence reading code and reviewing changes. The emphasis is on practicing coding fundamentals and reviewing existing code, not generating a finished application.
When an AI assistant contributes code to a project, the developer still needs to understand whether the code behaves as expected. Unrust's focus on tracing, debugging, idioms, and flaw recognition gives learners a place to work on those skills directly. By keeping diagnostic work free of AI and autocomplete, the service makes the learner's own interpretation central. Optional practice features provide a paid path for continued work beyond the available free diagnostic and account features. This makes Unrust relevant to developers who want an unassisted way to test their coding knowledge and practice reviewing code for quality and behavior.