Why Tach?

Modern Codebases are Complex

Many Python projects start as small, simple scripts. But over time, they tend to grow into a complex web of thousands of modules, with messy dependencies that can cause bugs and slow down development.

Large Python codebases become especially difficult when:

• Refactoring is risky because dependencies are opaque
• Adding features becomes a fearful experience
• Changes have unknown ripple effects
• Teams need boundaries between code areas
• Module APIs aren't explicit

Existing Solutions Fall Short

There are some existing tools for managing Python dependencies:

• Type checkers: Help catch issues with dynamic typing, but don't enforce module boundaries
• Linters: Can alert on styling issues, but don't generally analyze module structure
• Package managers: Manage external dependencies, but don't handle internal module dependencies
• Tests: Verify functionality, but don't enforce architecture
• Manually managed dependency rules: Hard to maintain and inconsistent

Tach is Purpose-Built for Modularity

Tach is designed to solve this specific problem. It gives you tools to:

• Define module boundaries in your codebase
• Control dependencies between modules
• Define explicit public interfaces to prevent deep coupling
• Gradually adopt in existing projects
• Integrate with your workflow: CI, pre-commit, etc.

Tach helps you build and maintain a modular Python architecture that can scale with your project as it grows.