The usethis._config.usethis_config singleton manages global application state (output verbosity, offline mode, backend selection) to avoid threading parameters through deep call stacks. However, its purpose and usage patterns were undocumented, and there was no guidance on when adding new global state is appropriate.

Changes

CONTRIBUTING.md - Architecture section

• Documents what usethis_config controls (message suppression, network access, frozen mode, backend, etc.)
• Shows context manager pattern for temporary overrides
• Illustrates CLI integration and internal usage patterns
• Establishes guidelines: only add state that affects application behavior across many commands, not command-specific logic

copilot-instructions.md - Architecture section

• Adds DO/DO NOT rules for global state usage
• Specifies requirements before adding new state (must be application-wide, not command-specific)
• Cross-references CONTRIBUTING.md for examples

Example Usage

# CLI commands apply flags via context manager
def my_command(offline: bool = offline_opt, quiet: bool = quiet_opt):
    with usethis_config.set(offline=offline, quiet=quiet):
        do_work()  # Entire execution uses these settings

# Deep functions access config without parameter threading
def internal_function():
    if usethis_config.quiet:
        return  # Skip output

The documentation emphasizes that usethis_config controls application behavior (how output is displayed, whether network is allowed), not business logic of individual commands.

• Fixes Document the usethis_config class better #1099

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.