Tech Tip: How to Connect the FeatureScript MCP Server and Claude Code

Onshape can help you generate CAD tools that create repeatable, robust parametric models.

An MCP server allows AI tools like Claude to securely connect to applications and use their capabilities. With Onshape Lab's FeatureScript MCP Server, Claude can help create, test, and refine custom CAD features using natural language.

FeatureScript is Onshape's native language for building parametric CAD features. Together, FeatureScript and MCP enable a powerful text-to-code-to-CAD workflow, making it easier to create reusable engineering tools tailored to your design process.

These steps install the Onshape FeatureScript MCP Server into Claude Code for both Windows and Mac machines.

Subscribe to the FeatureScript MCP App

First, get access to the FeatureScript MCP Server app.

1. Log in to your Onshape account.
2. Open the Onshape App Store and search for FeatureScript MCP Server.
3. On the app page, click Subscribe.
4. Go to your Application Settings and confirm Onshape appears in the list.

Subscription complete. Now let's set up the connection in Claude.

For Windows, Add Onshape to Your System PATH

(Windows only) Add Onshape to your system PATH so Claude can locate it. Mac users can skip ahead to the next step.

1. Press the Windows key, type environment variables, then select Edit the system environment variables.

2. Click Environment Variables in the bottom right, then click Edit in the Path row.

3. Click New and type the following, replacing USERNAME with your machine user name: C:\Users\USERNAME\.local\bin

4. Click Save, then click OK.

With the path set, let's move on to configuring Claude.

Install Claude Code

Next, install Claude Code. If you already have it installed, skip ahead to the next section.

1. Go to claude.ai and log in with your email address.

2. Open Terminal on Mac or PowerShell on Windows, navigate to where you want to install Claude, then run the install command for your operating system:

• Mac: curl -fsSL https://claude.ai/install.sh | bash
• Windows: irm https://claude.ai/install.ps1 | iex

3. Once the install finishes, confirm it worked by typing: claude --version

With Claude Code installed, we're ready to connect it to the MCP Server.

Add the MCP Server

Now, connect Claude Code to the Onshape FeatureScript MCP Server.

1. Open your terminal and paste the following command: claude mcp add --transport http onshape https://fs-mcp.labs.onshape.app/mcp

With the MCP Server added, Claude Code is now connected to Onshape.

Launch and Authorize Claude

Next, launch Claude Code and authorize your Onshape subscription.

1. Type claude and press Enter to launch Claude Code.

2. Follow the on-screen prompts until you're asked to authorize your subscription.

3. When a browser window opens, click Authorize, then close the window.

4. Return to your terminal and press Return to confirm.

With Claude authorized, you're ready to start using the FeatureScript MCP Server.

Authenticate the MCP Server

1. Inside the Claude Code terminal, type /mcp. This brings up the authentication screen. Follow the prompts to connect your Onshape account.

2. Once authenticated, press Escape to return to the main terminal.

Test the Server

Let's confirm everything is working.

1. Create a new document in Onshape and copy its URL.

2. In the Claude Code terminal, ask Claude to create a new Feature Studio named FS1 in that document, pasting in your URL: Create a new Feature Studio named FS1 in this document: [URL]

You should see FS1 appear directly in your Onshape document.

If you ever see a message that tools are unavailable, return to the previous step and re-authenticate using the /mcp command.

Set API Allocation (Optional)

If your organization has a company API allocation, you can tell Claude to use that instead of your personal one.

1. In the Claude Code terminal, type: Use the Onshape company API allocation, not my user API allocation.

Start Building Custom CAD Features

This Tech Tip walks you through connecting Claude Code to the Onshape FeatureScript MCP Server, so you can start building custom CAD features using natural language.

Want to go deeper? Check out the FeatureScript introduction in the Help documentation, which includes tutorials, standard library documentation, and dozens of example custom features to explore.