AI agent quickstart

In this guide you create an environment holding Claude Code and the frontend-design plugin, check what the agent will get, and launch it. You need Flox installed, a free FloxHub account, and a Claude account. For the ideas behind it (harnesses, plugins and sandboxes), see AI coding agents.

Log in and enable the extension

Installing packages from the Flox Catalog needs you to be logged in to FloxHub. Log in once per machine:

flox auth login

flox agent is a beta Flox extension, and Flox only runs beta commands once you opt in. Turn on beta features once:

flox config --set features.beta true

Create the environment

The environment holds everything the agent gets. Whatever you install into it is pinned in its lockfile, so anyone who activates the same environment gets the same agent and plugins. Make a folder for your project and create an environment in it:

mkdir my-agent && cd my-agent && flox init

Install the harness, a plugin, and the flox agent extension:

flox install agent-stacks/claude-code agent-stacks/agent-plugin-frontend-design flox/flox-agent

agent-stacks/claude-code is the harness: the Claude Code program.
agent-stacks/agent-plugin-frontend-design is an agent plugin with a skill for building polished web interfaces.
flox/flox-agent provides the flox agent command.

See what the agent gets

Activating the environment puts its packages, including flox agent, on your PATH:

flox activate

Then list the stack. flox agent list reads what is installed and shows what a launch would hand each harness, without starting anything:

$ flox agent list
Agent stack
1 harness · 1 plugin · 1 skill · 0 MCP servers

Harnesses
 ✔ claude            claude-code 2.1.304 · skills, MCP, hooks

Plugins
 ✔ frontend-design   agent-plugin-frontend-design 0.0.0-unstable.2026-10-19.ga0b04d9 · 1 skill

--long shows each plugin's skills and MCP servers.
Shows what launch gives each harness; agent-stacks writes nothing to a harness's own config.

Each row names the package and version it came from. Run flox agent list --long to see the skills each plugin provides.

Launch the agent

flox agent launch claude

flox agent launch starts Claude Code with the environment’s plugins. It stages them inside the environment, so your own Claude Code settings in your home directory are left as they are. Claude Code starts with the frontend-design skill loaded. Ask it to build a page, and it uses the skill. To pass flags to Claude Code, put them after --:

flox agent launch claude -- --continue

Add or remove plugins

Plugins are packages, so you manage them with the usual commands. Browse the available plugins with flox search:

flox search agent-plugin

Install another one with flox install, or remove one with flox uninstall. The next flox agent launch picks up the change.

If something is missing

flox agent doctor reports the plugins it found, each harness’s readiness, and the package to install for a harness that is missing:

flox agent doctor

Next steps

Launch an agent in a sandbox
Audit an agent plugin before you install it
flox agent launch reference

Get started

Guides

Command reference

AI agent quickstart

Log in and enable the extension

Create the environment

See what the agent gets

Launch the agent

Add or remove plugins

If something is missing

Next steps

​Log in and enable the extension

​Create the environment

​See what the agent gets

​Launch the agent

​Add or remove plugins

​If something is missing

​Next steps

Log in and enable the extension

Create the environment

See what the agent gets

Launch the agent

Add or remove plugins

If something is missing

Next steps