<user_input>$ARGUMENTS</user_input>
If <user_input/> contains a directory or file then that is what should be examined against this guide specifically. Start immediately. If it is 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="python-engineering:typer")— Typer CLI framework API reference- For Rich API reference, see
../python3-cli/references/rich-console-and-markup.mdand related Rich references
Non-TTY and Programmatic Usage
Consult python-engineering:standards-for-python-development for the shared rules (architecture, typing, testing, CLI rules).
See ../python3-cli/references/typer-rich-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 ../python3-cli/references/typer-rich-tables.md — width measurement pattern that prevents wrapping at 80 columns in non-TTY output.
Testing Patterns
See ../python3-cli/references/typer-rich-testing-patterns.md — capturing Rich output in pytest, CliRunner with Rich, snapshot testing, common assertion mistakes.
Exception Chain Prevention
See ../python3-cli/references/typer-rich-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 ../python3-cli/assets/typer_examples/index.md — working scripts demonstrating non-TTY display solutions. Read when troubleshooting display and layout of terminal applications.
See ../python3-cli/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.