In the web and desktop clients, open Settings → Plugins to browse Codex, Claude Code, and Cursor plugins from the current environment. You can also use the Plugins button at the bottom of the sidebar or open the command palette and choose Browse plugins.
The marketplace reads installed and available packages from configured Codex and Claude Code marketplaces, including Codex's bundled plugins and its official remote catalog. It also reads Cursor's public marketplace and local Cursor plugin cache. When this environment is signed in to ChatGPT through Codex, search also queries ChatGPT's public plugin index, so listings that only appear there — such as TickTick — show up in results.
The page has four sections. Plugins lists every marketplace bundle: installed plugins first,
then featured picks and each category. Apps and MCPs narrow the catalog to plugins that
bring an app connector or MCP servers. Skills lists the standalone skills installed on this
environment, then the plugins that bundle skills; open a skill to read its SKILL.md, or use
Settings → Skills to see the skills on every connected computer. Each section's count is what
you have installed: plugins, and the apps, MCP servers, and skills they ship. Remote Codex plugins
publish their contents only once installed, so an uninstalled one may not appear under Apps or MCPs
yet.
Use the harness menu beside the search box to show only Codex, Claude Code, or Cursor, and the filter button to narrow by install status or category. A plugin that only one harness offers can be installed straight from its card with the plus button; open any listing to manage each harness copy, remove it, or connect its accounts. Each listing names the marketplace it comes from, such as Codex official or Bundled, and plugin artwork and metadata come from the package or its published marketplace listing. Equivalent category names from different marketplaces are combined into one category.
Each harness loads independently. If one takes a while to sync its marketplaces, the page shows the others right away with a notice that the slow harness is still syncing, and fills it in automatically when it finishes. If a harness cannot be read at all, its notice explains why and offers a retry while the rest of the catalog stays usable.
Marketplace changes use the configured binary, home directory, and environment of that harness's provider instance. If more than one enabled instance of the same harness is configured, manage its plugins with the provider directly until per-instance marketplace selection is available.
Same-named packages from different harnesses appear as one listing. The detail page still installs and removes each harness copy separately and shows that package's published MCP servers and components.
Package contents are shown in the terms used by each harness. Codex bundles skills, MCP connections, apps, and optional hooks. Claude Code packages can also include namespaced commands, subagents, language servers, and monitors. Cursor packages can include editor rules, commands, subagents, hooks, skills, and MCP servers. T3 Code reads Cursor's published inventory directly and inspects the source of remote Claude packages when you open their details.
Installation switches update the real Codex or Claude Code configuration on that environment.
When a Codex message explicitly mentions an installed plugin with $plugin-name, T3 Code forwards
that plugin's enabled skills with the turn, including in an existing thread. Start a new chat after
changing MCP servers or apps so the harness can refresh those longer-lived connections.
Remote HTTP MCP servers that require OAuth have an MCP authentication section after installation. Select Connect to open the provider's authorization page. Codex usually completes the loopback flow in the browser; if it opens its own sign-in window instead, finish there and return to T3 Code. Claude Code may ask you to paste the full callback URL back into the plugin page when the environment is remote. Connection status and Disconnect use each harness's native credential store, so T3 Code never keeps a separate copy of the access or refresh token. Cursor connections continue in Cursor's own settings. Local standard-input MCP servers do not use the HTTP OAuth flow.
On macOS, the Computer Use detail page includes Permission setup. Open the signed Computer Use setup app there to grant Accessibility and Screen Recording, or jump directly to the Accessibility and Automation pages in System Settings. T3 Code declares its Automation purpose to macOS so the system can show consent prompts for the applications you choose. When browsing a remote environment, these actions open on the Mac hosting that environment.
Cursor does not currently provide a non-interactive plugin install command, so Cursor rows open the official Cursor Marketplace for installation or removal. ChatGPT Public listings open the ChatGPT plugin directory the same way. Secret environment variable values are never displayed.