Typer and Rich Best Practices

<user_input>$ARGUMENTS</user_input> If <user_input/> contains a directory or file then that is what should be examines against this guide specifically. Start immediately. If its empty, then use this as a reference for existing tasks.

Correctness patterns for building CLI applications with Typer and Rich, focused on non-TTY environments and common failure modes. For API reference, load the dedicated skills:

• Skill(skill="python3-development:typer") — Typer CLI framework API reference
• Skill(skill="python3-development:rich") — Rich terminal UI API reference

Non-TTY and Programmatic Usage

Consult ../python3-development/references/python3-standards.md when applying shared architecture, typing, testing, or CLI rules; full standards, graphs, and amendment process are documented there.

See references/non-tty-patterns.md — Console behavior without TTY, width defaults, force_terminal vs width, Progress/Live in non-interactive contexts, environment variables.

Rich Table Width Measurement

See references/rich-tables.md — width measurement pattern that prevents wrapping at 80 columns in non-TTY output.

Testing Patterns

See references/testing-patterns.md — capturing Rich output in pytest, CliRunner with Rich, snapshot testing, common assertion mistakes.

Exception Chain Prevention

See references/exception-handling.md — Typer exception chain prevention with AppExit and AppExitRich patterns. Read when implementing error handling in Typer CLI applications.

Working Script Examples

See assets/typer_examples/index.md — working scripts demonstrating non-TTY display solutions. Read when troubleshooting display and layout of terminal applications.

See assets/python-cli-demo.py — complete working CLI demo with all patterns (PEP 723 shebang, Typer + Rich integration, modern Python 3.11+, async processing). Read when creating a new CLI tool as a reference implementation.