| name | rust-cli |
| description | Design, implement, test, document, and release Rust command line applications using Cargo, clap, integration tests, error handling, and CLI UX conventions. Use when Codex is asked to build or review a Rust CLI, add commands or flags, improve tests, package releases, or debug Cargo workflows. |
rust-cli
Workflow
- Gather Cargo workspace, command, flag, and test context.
- Determine user-facing CLI behavior and compatibility impact.
- Create rollback by keeping changes scoped and tests focused.
- Implement the smallest parser, command, or library change.
- Validate formatting, linting, tests, help text, and exit codes.
Diagnostics
cargo metadata --no-deps
cargo fmt --check
cargo clippy -- -D warnings
cargo test
cargo run -- --help
cargo run -- <command> --help
Safety Rules
- Keep parsing, command execution, and reusable logic separated.
- Print normal output to stdout and diagnostics to stderr.
- Never change CLI output formats casually if scripts may depend on them.
- Return non-zero exit codes for failed operations.
- Follow existing crate and workspace conventions before adding abstractions.
Validation
cargo fmt --check passes.cargo clippy -- -D warnings passes when feasible.- Unit and integration tests pass.
--help and command help are accurate.- Success and failure paths return expected exit codes.
