# Quickstart **Outcome:** Atomic is installed, authenticated, and has completed one useful task in your repository. Follow the steps below to install Atomic and complete your first useful session. Atomic runs coding-agent loops with stages, tools, artifacts, verification, subagents, review gates, checkpoints, and human approvals for engineering work. Work through the steps in order. Each links to a focused page with full instructions. ## Onboarding path 1. **[Install Atomic](/getting-started/installation)** — package manager or self-contained release archive. 2. **[Authenticate](/getting-started/authentication)** — subscription login or API key. 3. **[Run your first session](/getting-started/first-session)** — start Atomic, run a task, invoke a built-in workflow, and steer the run. 4. **[Add project instructions](/getting-started/project-instructions)** — teach Atomic your repository's conventions with `AGENTS.md`. Then come back here for [common things to try](#common-things-to-try) and [next steps](#next-steps). ## Prerequisites - **Package install:** Node.js 22.19 or newer plus npm, pnpm, Yarn, or Bun. Use Bun 1.4.2+ for Bun installs or workflow-authoring examples. - **Release archive install:** macOS and Linux need `tar` and either `curl` or `wget`; Windows uses built-in PowerShell commands. This path does not need Node.js or a package manager. - **Model-provider access** — use a supported subscription login or API key. Run `/login` after startup. ## Install The install commands and every installer knob, default path, and platform note now live on the installation page. Moved to [Installation](/getting-started/installation#install). ### Package managers Moved to [Installation](/getting-started/installation#package-managers). Full detail: package manager commands and the `--ignore-scripts` note. ### Release archive Moved to [Installation](/getting-started/installation#release-archive). Full detail: version pinning, `ATOMIC_VERSION`, `ATOMIC_INSTALL_DIR`, `ATOMIC_BIN_DIR`, `GITHUB_TOKEN`/`GH_TOKEN`, rerunning the installer (it skips the download when the version is already installed; `--force`, `-Force`, or `ATOMIC_FORCE_INSTALL=1` reinstalls), default paths, and PATH guidance. It also describes what the installer prints: the release and platform, a live download progress bar, one-line phase confirmations, the Atomic logo, and a `To start:` block, or plain text when `NO_COLOR=1` is set, `CI` is set, or output is not a terminal. #### ATOMIC_VERSION Moved to [Installation](/getting-started/installation#atomic_version). #### ATOMIC_INSTALL_DIR Moved to [Installation](/getting-started/installation#atomic_install_dir). #### ATOMIC_BIN_DIR Moved to [Installation](/getting-started/installation#atomic_bin_dir). #### GITHUB_TOKEN / GH_TOKEN Moved to [Installation](/getting-started/installation#github_token-/-gh_token). ### Which runtime runs your workflows Moved to [Installation](/getting-started/installation#which-runtime-runs-your-workflows). ### Alpine and musl Linux archives Moved to [Installation](/getting-started/installation#alpine-and-musl-linux-archives). ## Uninstall Moved to [Installation](/getting-started/installation#uninstall). Full detail: removing the install root, the launcher, and the PATH entry on every platform. ## Authenticate Moved to [Authentication](/getting-started/authentication#authenticate). Full detail: `/login` subscription providers and API-key environment variables. ### Option 1: subscription login Moved to [Authentication](/getting-started/authentication#option-1-subscription-login). ### Option 2: API key Moved to [Authentication](/getting-started/authentication#option-2-api-key). ## First session Moved to [First session](/getting-started/first-session#first-session-2). Full detail: starting Atomic, the built-in workflows, monitoring and steering a run, top skills, creating a workflow in natural language, and the default tools and prompts. ### Try the built-in workflows Moved to [First session](/getting-started/first-session#try-the-built-in-workflows). ### Monitor and steer a run Moved to [First session](/getting-started/first-session#monitor-and-steer-a-run). ### Top skills to invoke directly Moved to [First session](/getting-started/first-session#top-skills-to-invoke-directly). ### Create your own workflow in natural language Moved to [First session](/getting-started/first-session#create-your-own-workflow-in-natural-language). ### Default tools and prompts Moved to [First session](/getting-started/first-session#default-tools-and-prompts). ## Give Atomic project instructions Moved to [Project instructions](/getting-started/project-instructions#give-atomic-project-instructions). Full detail: `AGENTS.md` discovery, precedence, and what to put in it. ## Common things to try ### Reference files Type `@` in any interactive editor to fuzzy-search files; or pass files on the command line: ```bash atomic @README.md "Summarize this" atomic @src/app.ts @src/app.test.ts "Review these together" ``` Paste images with native macOS Cmd+V or Ctrl+V. On Windows, use Alt+V instead of Ctrl+V. You can also drag images into supported terminals. Inside tmux on macOS, use `Ctrl+V` for reliable image paste. Native `Cmd+V` depends on your terminal and may not work through tmux. When the clipboard contains both text and an image, Ctrl+V prefers the image. Cmd+V may paste either, depending on how the terminal delivers the gesture. ### Run shell commands In interactive mode: ```text !bun run lint ``` The command output is sent to the model. Use `!!command` to run a command without adding its output to the model context. ### Switch models Use `/model` or CTRL+L to choose a model. Use SHIFT+Tab to cycle thinking level. Use CTRL+P / SHIFT+CTRL+P to cycle through scoped models. ### Continue later Sessions are saved automatically: ```bash atomic -c # Continue most recent session atomic -r # Browse previous sessions atomic --name "my task" # Set session display name at startup atomic --session # Open an exact ID or unique 8-hex UUID prefix atomic --import # Import a format-4 JSONL export ``` Inside Atomic, use `/resume`, `/new`, `/tree`, `/fork`, and `/clone` to manage sessions. ### Non-interactive mode For one-shot prompts: ```bash atomic -p "Summarize this codebase" cat README.md | atomic -p "Summarize this text" atomic -p @screenshot.png "What's in this image?" ``` Use `--mode json` for JSON event output or `--mode rpc` for process integration. ## Next steps - [Using Atomic](/usage) - interactive mode, slash commands, sessions, context files, and CLI reference. - [Workflows](/workflows) - run, inspect, and author multi-stage automation (including the built-in workflows). - [Skills](/skills) - reusable expert instructions invoked with `/skill:`. - [Providers](/providers) - authentication and model setup. - [Settings](/settings) - global and project configuration. - [Keybindings](/keybindings) - shortcuts and customization. - [Atomic Packages](/packages) - install shared extensions, skills, prompts, and themes. - [Security](/security) - project trust, what Atomic is allowed to touch, and how to report a vulnerability. Read this before you trust a project or install someone else's skills, extensions, or packages. - [Containerization](/containerization) - run Atomic or its tools inside an isolated environment. Platform notes: [Windows](/windows), [Termux](/termux), [tmux](/tmux), [Terminal setup](/terminal-setup), [Shell aliases](/shell-aliases).