# Use Specset from Codex

> Install the Specset plugin in Codex to search construction documents, manage project workflows, and transfer files with shared skills and native MCP tools.

Source: https://docs.specset.com/docs/chatgpt-codex · Section: Agents · Last updated: 2026-10-08

The Specset plugin gives Codex the same construction workflows available in the [Claude plugin](https://docs.specset.com/docs/claude-plugin). It bundles skills plus a native MCP connector for project search and structured reads, all powered by the `specset` CLI.

## Install the Codex plugin

Add the public Specset marketplace, then install the plugin:

```bash
codex plugin marketplace add specsetai/specset-plugins
codex plugin add specset@specset-plugins
```

Start a new Codex session after installation so the bundled skills and MCP tools load. You can also run Codex interactively and enter `/plugins` to inspect installed plugins by marketplace.

If your organization installs plugins through the Codex desktop app, open **Plugins**, find **Specset**, and click **+**. Workspace policy can control which plugins are available.

## First run: sign in

Ask Codex a Specset question. The core skill checks the CLI, starts browser sign-in when a browser is visible, and uses device authorization in remote or headless environments:

```bash
specset login --device
```

Approve the displayed code, choose your Specset organization, and start a new Codex session if the MCP tools were not available before sign-in. Credentials remain in the local CLI; Codex receives project data through the authenticated MCP tools.

Try prompts such as:

> *"Find the product data requirements for the air handling units."*

> *"Compare this submittal PDF with the applicable specification sections."*

> *"Show me the latest RFIs that affect concrete work."*

## Upload and download files

The local Codex plugin can work with file paths on your computer. When a workflow needs an attachment, Codex uses the streaming upload command and passes the returned cloud file ID to Specset:

```bash
specset files upload ./submittal.pdf --json
```

Downloads use the matching project or record download command. The CLI streams bytes directly, so the agent does not need to hold the complete file in memory.

## Check the connection

Start with a read-only request such as “List the projects I can access in Specset.” This checks that sign-in, the selected organization, and project access are working before you try an upload or a workflow that changes records.

If the expected project is missing, confirm which organization is selected and whether your account has access to that project. If the Specset tools are missing altogether, confirm the plugin is installed, complete sign-in, and start a new session. For a file workflow, ask the agent to check the upload command before sending the file:

```bash
specset files upload --help
```

## Keep the plugin current

Refresh the marketplace, reinstall the latest plugin snapshot, and update the CLI:

```bash
codex plugin marketplace upgrade specset-plugins
codex plugin add specset@specset-plugins
npm install -g @specset/cli@latest
```

Start a new session after an update.

## Connect ChatGPT through hosted MCP

Codex runs the plugin and CLI locally. ChatGPT connects to Specset's hosted MCP endpoint instead, so it can use the same tool registry without access to local paths.

1. In ChatGPT, open **Settings → Security and login** and enable **Developer mode** if your account and workspace allow it.
2. Open **Plugins**, click **+**, and create a connection to `https://app.specset.com/mcp`.
3. Complete Specset sign-in and select the organization to bind to the connection.
4. Start a new chat with the Specset connection enabled.

For hosted file workflows, ChatGPT passes an attached file through a short-lived OpenAI file URL to Specset's `uploadFile` tool. Downloads return a short-lived resource link through `getFileDownload`. Local file paths are never exposed to the hosted MCP server.