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Cosine

Quickstart

Use this guide when you want the fastest path from zero to a working CLI session, ready to start building with Cosine agentically.

1. Install the CLI

Section titled “1. Install the CLI”

Choose one install method for your platform.

macOS or Linux

Section titled “macOS or Linux”
Terminal window
brew install CosineAI/tap/cos
cos --version

Linux alternative

Section titled “Linux alternative”
Terminal window
curl -fsSL https://cosine.sh/install | bash
cos --version

Windows

Section titled “Windows”
Terminal window
winget install Cosine.CLI
cos --version

If you need direct download instructions or dependency notes, see Install & Authenticate.

2. Sign in

Section titled “2. Sign in”
Terminal window
cos login

This opens your browser and connects the CLI to your Cosine account.

3. Open your repository

Section titled “3. Open your repository”

Change into the project directory you want to work in:

Terminal window
cd /path/to/project

If you want Cosine to create repo-local config files, run:

Terminal window
cos init

If you want to connect this folder to a Cosine project for deployment and project-aware commands, run:

Terminal window
cos project init

If the folder does not have a GitHub remote yet, Cosine can offer to create one with the GitHub CLI, commit the current project, push it, and save the Cosine project link. Each prompt has a default, so you can press Enter through the setup flow.

4. Start the CLI

Section titled “4. Start the CLI”
Terminal window
cos start

This opens the interactive terminal user interface (TUI) in your current repository.

Work with Git

Section titled “Work with Git”

When Cosine edits files in a Git repository, it can create an Agent Commit at the end of each editing turn so those changes stay visible, reviewable, and reversible in your normal workflow. If you prefer, you can also disable this behavior.

See Agent Commits for review and recovery.

5. Try your first task

Section titled “5. Try your first task”

Inside the CLI, try a concrete prompt such as:

  • Explain the architecture of this repository
  • Find the authentication flow and summarize it
  • Add a test for the date formatting utility

You can also run a one-shot task from the shell:

Terminal window
cos start --prompt "Explain the main entrypoint of this repository"

6. Learn the next layer

Section titled “6. Learn the next layer”
  • Overview — Understand the product and mode model
  • Commands — See the main commands and look up flags such as --cwd, --model, and --auto-accept
  • Linked Projects — Connect a local folder to a Cosine project
  • Instant Sites — Deploy a static site with cos deploy
  • Modes — Understand Manual, Auto, Plan, and Swarm