GitHub Copilot CLI

Why it's ranked here

This is about as close as it gets to an official reference implementation: GitHub builds it, ships it under its own proprietary license, and distributes it through an install script, Homebrew, WinGet, and npm rather than one narrow channel. It defaults to Claude Sonnet 4.5 but lets you switch models, and it layers in a broad extensibility surface: custom tool servers, language server hookups, and a plugin system covering skills and instructions. The changelog we read shows continuous, wide-ranging feature work rather than a stalled side project, which earns it a high spot among terminal coding agents.

What's good

The safety model is concrete, not aspirational: every planned action is shown before it runs, so you are approving specific edits and commands rather than trusting a black box. Installation is unusually well covered too, with a script, Homebrew, WinGet, and npm all pointing at the same binary, and the script itself checks a downloaded checksum file before ever unpacking anything. Model choice is not locked in either: the default is Claude Sonnet 4.5, but a single command switches to alternatives including GPT-5.

Tradeoffs

None of this is free or open: you need an active, paid Copilot subscription just to launch it, and every prompt you send draws down a monthly quota of premium requests, so heavy use has a ceiling built in. The license is not an open source one either. It lets you run and redistribute unmodified copies bundled inside something bigger, but forbids modifying the software or building anything derivative from it. Code intelligence is opt-in work too, since language servers are not bundled and each one has to be installed and pointed at manually.

How to use it well

This fits developers already living in the GitHub ecosystem who want an agent that can act across code and project management in one terminal session, not just edit files. Point it at a repository, let it work alongside your issues and pull requests, and lean on the approval prompts rather than disabling them, since that per-step check is the main safety net. Pair it with a language server for your primary language if you want real code intelligence, since none comes installed by default. It is not built for offline work or teams avoiding a subscription-gated assistant.

Observed

License

GitHub's own proprietary license, not an OSI open source license; forbids modifying the software or creating derivative works

Redistribution terms

Unmodified copies may be redistributed only when bundled into an application or service that adds functionality beyond the software itself, never standalone

Platform support

Linux, macOS, and Windows

Installation channels

Install script, Homebrew, WinGet, and npm all distribute the same binary

Interfaces

Interactive terminal CLI with slash commands; acts as an MCP client (bundled GitHub MCP server plus custom servers) and an LSP client (servers installed separately)

Install script integrity check

The install script validates the downloaded tarball against a checksums file with sha256sum or shasum before extraction, when that file is available