How to Install Plugins for Personal Use from the OpenAI Plugins Repository

To install plugins for personal use, register the official marketplace in your coding assistant harness, then execute the tool-specific installation command to pull the plugin manifest and activate its capabilities.

The openai/plugins repository hosts a curated collection of Codex-compatible plugins designed to extend AI coding assistants. Each plugin resides under plugins/<name>/ and contains a mandatory manifest file that defines its capabilities and permissions. Personal installation follows a standardized three-step workflow supported across major harnesses including Claude Code, Cursor, and the Codex App.

The Three-Step Installation Workflow

The installation process is standardized across coding assistant platforms, ensuring you can add functionality quickly regardless of your preferred tool.

1. Choose a Marketplace

All plugins are indexed through a marketplace definition located at .agents/plugins/marketplace.json in the repository root. This JSON file maps plugin names to their local source directories and defines authentication requirements. The default marketplace ships with the repository and provides the canonical reference for available plugins.

2. Register the Marketplace

Before installing individual plugins, you must register the marketplace with your coding assistant harness. This one-time step enables the tool to resolve plugin names to their source locations. Registration commands vary by platform—refer to the "Installation" section in plugins/superpowers/README.md for concrete examples specific to your harness.

3. Install the Desired Plugin

Once the marketplace is registered, invoke your harness-specific install command with the plugin name. The assistant will pull the plugin manifest from .codex-plugin/plugin.json, resolve the source location (local path, URL, or git submodule), and prompt for any required authentication.

Harness-Specific Installation Commands

While the underlying workflow remains consistent, the exact command syntax differs across coding assistant platforms according to the source code documentation.

Claude Code uses the slash command:

/plugin install <plugin>@<marketplace>

Cursor provides a dedicated plugin command:

/add-plugin <plugin>

Codex App offers a graphical interface—open the Plugins sidebar, locate the desired plugin, and click the + button next to its name. Alternatively, use the global /plugins command to access the search interface.

Codex CLI opens an interactive plugin search UI when you type /plugins. Type the plugin name and select Install Plugin from the results.

OpenCode requires fetching the installation script from the plugin's .opencode/INSTALL.md file and following its instructions manually.

How Installation Works Under the Hood

When you execute an install command, the harness performs several validation steps defined in the openai/plugins source code.

First, the tool reads the plugin manifest at plugins/<name>/.codex-plugin/plugin.json to discover capabilities, required permissions, and companion assets. This manifest is mandatory for every plugin in the repository.

Next, the harness resolves the plugin source using the mapping defined in .agents/plugins/marketplace.json. Sources may include local filesystem paths, public URLs, or git submodules.

Finally, the system handles authentication according to the marketplace definition. Most plugins in the collection use the "ON_INSTALL" authentication trigger, prompting you for credentials or API keys during the installation process rather than at runtime.

Practical Installation Examples

Register the official Codex marketplace once per environment:

/plugin marketplace add obra/superpowers-marketplace

Install the Superpowers plugin for Claude Code:

/plugin install superpowers@superpowers-marketplace

Install a custom plugin from a public GitHub repository in Cursor:

/add-plugin https://github.com/obra/superpowers

For the Codex App, navigate to the Plugins sidebar, find "Figma" in the list, and click the + button to activate it.

Summary

• The openai/plugins repository provides Codex-compatible plugins under plugins/<name>/, each requiring a manifest at .codex-plugin/plugin.json.
• Personal installation requires three steps: selecting the marketplace defined in .agents/plugins/marketplace.json, registering it with your harness, and running the install command.
• Claude Code uses /plugin install, Cursor uses /add-plugin, while Codex App and CLI provide interactive UI options.
• Most plugins trigger authentication prompts during installation ("ON_INSTALL") rather than at runtime.
• OpenCode installations require manual execution of scripts found in .opencode/INSTALL.md.

Frequently Asked Questions

Where is the default plugin marketplace defined?

The default marketplace is defined in .agents/plugins/marketplace.json at the repository root. This file maps plugin names to their local source directories and specifies authentication requirements for each plugin in the collection.

What file must every plugin contain?

Every plugin must contain a manifest file at .codex-plugin/plugin.json. This JSON file declares the plugin's capabilities, required permissions, version information, and asset locations. Without this manifest, the harness cannot discover or install the plugin.

How do I install plugins in Claude Code specifically?

In Claude Code, first register the marketplace using /plugin marketplace add <marketplace-name>, then install specific plugins with /plugin install <plugin>@<marketplace>. For example: /plugin install superpowers@superpowers-marketplace.

What authentication method do most plugins use?

According to the marketplace definition in .agents/plugins/marketplace.json, most plugins use the "ON_INSTALL" authentication trigger. This means the harness prompts you for necessary credentials or API keys during the installation process, ensuring the plugin is fully configured before you attempt to use it in a coding session.

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