4. Install

This guide uses the Claude Code plugin as the default path. The order is login, plugin install, ooo setup, then verification.

Ouroboros 0.50.4upstream 456a134verified 2026-07-16 against docs and code

Diagram of the four install steps: login, plugin, setup, verify — Installation is four steps: login, plugin, setup, verify.

4.1 Prerequisites

Claude Code with plugin support must be installed.
Python is not required. The Claude Code plugin path works without a Python install.
On Windows, follow the Linux steps inside WSL 2.

Open a Claude Code session in your terminal.

claude

/login

Expected result: after browser authentication, the session shows you are logged in. Without login, later ooo commands will not work.

4.3 Install the plugin

Run the next two commands in a normal terminal, outside Claude Code.

claude plugin marketplace add Q00/ouroboros
claude plugin install ouroboros@ouroboros

Terminal output showing the Ouroboros 0.50.4 plugin installed in Claude Code — Install output captured on 2026-07-16 on Ubuntu 24.04 with Claude Code 2.1.210.

Expected result: claude plugin list shows ouroboros@ouroboros as enabled.

4.4 ooo setup — connect Core over MCP

Open a Claude Code session in the project folder you will work in, and type:

ooo setup

ooo setup registers the Ouroboros Core MCP server globally. Registration is needed only once. Optionally it adds a command summary to the project's CLAUDE.md.

Expected result: a message confirms the MCP server registration. Per the official docs, the registration is written to ~/.claude/mcp.json. Close Claude Code completely and reopen it after registering.

4.5 Verify

Run this inside the Claude Code session.

ooo help

Expected result: a command list including interview, seed, run, and evaluate. If it does not appear, see chapter 11.

4.6 Update

Run this inside the Claude Code session.

ooo update

Expected result: the current and latest versions are compared and updated to match your install method. Reopen the Claude Code session afterwards.

4.7 Definition of done

claude plugin list shows ouroboros@ouroboros as enabled.
ooo help prints the command list.
Claude Code's /mcp shows the ouroboros server as connected.

Installing from the terminal without Claude Code

The standalone CLI requires Python 3.12 or later and installs from a normal terminal.

pip install ouroboros-ai
ouroboros setup

Other runtimes such as Codex CLI are selected with ouroboros setup --runtime codex. The main text of this guide uses Claude Code's ooo commands.