Installation

Before you start: what you need

• Adobe® InDesign®, installed and running – Mac or Windows (Windows 10/11 x64; tested with InDesign® 21.6.0 on Windows 11)
• Claude Desktop with your own account
• Node.js version 20 or newer – only for Way B (entry in the configuration file) and for other MCP clients; checked and installed in steps 1 and 2. With the installation package (Way A) no separate Node.js installation is needed – Claude Desktop comes with Node.js.
• Windows: Windows PowerShell 5.1 (powershell.exe, included in Windows)
• Your licence key from the order confirmation or the Polar customer portal – one key per workstation
• A network connection for the licence check on the first call

Step 1 – Check Node.js (Way B only)

If you set up LayoutBridge with the installation package (Way A in step 3), skip steps 1 and 2 and go straight to step 3.

node -v

node -v

Step 2 – Install Node.js (Way B only, only if needed)

1. Go to nodejs.org and download the LTS version – the .pkg installer on Mac, the .msi installer on Windows. Older versions are updated the same way.
2. Run the installer with its defaults. On Windows, the option to install additional tools (“Tools for Native Modules”) can stay unticked.
3. Close Terminal or PowerShell, open it again and repeat step 1. Only a newly opened window knows the freshly installed Node.js.

If you manage Node.js with Homebrew, nvm, fnm or Volta, keep doing so – all that matters is version 20 or newer.

Step 3 – Register LayoutBridge in Claude Desktop

There are two ways. Way A is the shorter one; Way B is the same entry that other MCP clients receive.

Way A – installation package (bundle file .mcpb, Claude Desktop)

1. Download the file layoutbridge-spm-1.0.0.mcpb (current version, also on the product page).
2. In Claude Desktop, open Settings › Desktop app › Extensions and drag the file into that window – it says “Drag .MCPB or .DXT files here to install”. On Mac you can open the file by double-clicking it instead. On Windows, double-clicking does not open Claude Desktop – Windows asks which app to use; drag the file into the window, or choose “Advanced settings” › “Install extension” and select the file. Claude Desktop shows the installation dialog; confirm with “Install”.
3. During installation, enter your licence key in the field “Licence key” and click “Save”. Claude Desktop stores the key on your computer.
4. Switch the extension on. After installation, “LayoutBridge for Adobe InDesign®” is listed under Settings › Extensions as “Disabled”. Switch it to enabled – otherwise no tools appear.

Way A needs no Node.js of your own: Claude Desktop runs the extension with its built-in Node.js (switch “Use built-in Node.js for MCP” under “Advanced settings”, on by default). This also completes step 4 – continue with step 5.

Way B – entry in the configuration file

Way B requires Node.js version 20 or newer (steps 1 and 2). Claude Desktop reads its MCP servers from a text file. Open it in a text editor (TextEdit in plain-text mode, Notepad on Windows, or a code editor):

~/Library/Application Support/Claude/claude_desktop_config.json

%APPDATA%\Claude\claude_desktop_config.json

If the file is empty or does not exist yet, its complete content is this:

{
  "mcpServers": {
    "layoutbridge-spm": {
      "command": "npx",
      "args": ["-y", "layoutbridge-spm"]
    }
  }
}

If the file already lists other servers under "mcpServers", insert only the block "layoutbridge-spm": { … } there – with a comma between the entries – and leave everything else unchanged. The file is JSON: every bracket and every quotation mark counts, and a missing or extra comma makes it invalid. Save the file without changing its name or extension.

On the first start, npx downloads the package layoutbridge-spm from the npm registry; after that it starts from the local cache.

Step 4 – Store the licence key (Way B)

The key is shown in the order confirmation and in the Polar customer portal and is valid for exactly one workstation. Store it as the file license.key – the key only, no other text, no blank line before it:

~/Library/Application Support/layoutbridge-spm/license.key

%USERPROFILE%\.layoutbridge-spm\license.key

Create the folder layoutbridge-spm or .layoutbridge-spm if it does not exist. A key added or changed later takes effect immediately, without a restart.

Alternatively, put the key directly into the server entry from step 3 – as a further line after "args", with a comma before it:

"env": {
  "LAYOUTBRIDGE_SPM_LICENSE_KEY": "YOUR-LICENCE-KEY"
}

Or name your own file path in the environment variable LAYOUTBRIDGE_SPM_LICENSE_FILE. Order in which LayoutBridge looks: environment variable holding the key, file named in LAYOUTBRIDGE_SPM_LICENSE_FILE, license.key at the default location.

Step 5 – Restart Claude Desktop and check

1. Quit Claude Desktop completely – on Mac with ⌘ + Q, on Windows via “Quit” in the application menu; closing the window is not enough – and start it again.
2. Start Adobe® InDesign®.
3. Ask in Claude Desktop: “Which InDesign® version is running?” Claude calls the tool get_app_version and reports the version. The first time a tool is used, Claude Desktop asks whether to allow it (“Deny / Always allow / Allow once”) – this is a Claude Desktop setting, not an error; for the installation package the default is under Settings › Extensions › tool permissions. On the first call LayoutBridge verifies the licence key online; after that at most once every 24 hours.

Setup is now complete. The tools appear in Claude Desktop under the extension name “LayoutBridge for Adobe InDesign®” on Way A, and with the prefix layoutbridge-spm: on Way B.

If something does not work

• The tools do not appear. Way A: the extension is still “Disabled” (step 3). Way B: Claude Desktop was not quit completely; or the configuration file is not valid JSON (usually a comma) – Claude Desktop reports this on start; or Node.js is missing (step 1).
• Message “Node.js … found, but version 20 or newer is required” (Way B only). The installed Node.js is too old. Update it as in step 2, check with node -v, then quit Claude Desktop completely and start it again.
• Reply with error.kind: "license". The key is missing, expired, invalid or cannot be verified right now. The message says in plain words which case applies and names the location where the key was expected. Check: copied completely, no spaces, correct path, network connection on the first call.
• Reply with app_not_available. Adobe® InDesign® is not running. Start it and repeat the request.
• Moving to another computer. A licence is active on one workstation. Release it on the old computer before entering the key on the new one – no InDesign®, no Claude Desktop needed, but Node.js version 20 or newer:

  npx layoutbridge-spm --deactivate

  The command looks for the key in the same places as LayoutBridge (step 4). With the installation package, Claude Desktop keeps the key and the command does not find it – store it as license.key first (step 4) or write to support. If you have no Node.js or the old computer is no longer available, support releases the activation.
• Anything else: write to support – with the tool name, the exact error text, the time, the InDesign® version and the operating system. Never send your licence key.

Instruction for your AI

If you use an AI application that is allowed to work on your computer – Claude Code, Claude in Cowork mode with computer access, Cursor, Codex CLI or any other application with access to the terminal and your files – copy the text below and paste it there as a message. The instruction sets up Way B (entry in the configuration file, with Node.js); you do not need it for the installation package (Way A). The AI checks Node.js, suggests the installation if needed, registers LayoutBridge in Claude Desktop and stores the key; it asks for your consent before every step. A chat without access to your computer can only explain the steps, not carry them out.

I want to set up LayoutBridge for Adobe InDesign (MCP server, npm package "layoutbridge-spm") on this computer for Claude Desktop. Please guide me step by step and follow these rules:

1. Consent before every action. Before every command and every file change, tell me what you intend to do and wait for my yes. Install nothing beyond what is listed here, change no other settings, and do not ask for administrator rights.

2. Check Node.js. Run "node -v". Version 20 or higher is expected. If Node.js is missing or older: do NOT install it yourself. Point me to the LTS download at https://nodejs.org (Mac: .pkg, Windows: .msi) and wait until I have installed it and reopened the terminal. Then check again.

3. Find the Claude Desktop configuration file.
   Mac: ~/Library/Application Support/Claude/claude_desktop_config.json
   Windows: %APPDATA%\Claude\claude_desktop_config.json
   Show me its contents. Before any change, create a backup copy in the same folder (file name with date and time). If the file is not valid JSON, do not change it – show me where the problem is.

4. Add the entry. Under "mcpServers", add exactly this entry and leave all other entries untouched. If the file does not exist, create it with this content:
{
  "mcpServers": {
    "layoutbridge-spm": {
      "command": "npx",
      "args": ["-y", "layoutbridge-spm"]
    }
  }
}

5. Licence key. I will give you the key myself. Write it – the key only, no other text – to the file "license.key", creating the folder if needed:
   Mac: ~/Library/Application Support/layoutbridge-spm/license.key
   Windows: %USERPROFILE%\.layoutbridge-spm\license.key
   Set the file so that only my user account can read it. Do not send the key anywhere, do not write it to any other file, and do not print it in any reply.

6. Wrap-up. Show me the output of "node -v", the new entry in the configuration file and the path of the key file. Tell me that I must quit Claude Desktop completely (not just close the window) and start it again.

7. Check after the restart. Adobe InDesign must be running. I will ask Claude Desktop: "Which InDesign version is running?" – the tool layoutbridge-spm:get_app_version should report the version; the key is verified online on the first call. If the tool answers with error.kind "license", help me find the cause from the message (it names the expected location of the key). If it answers "app_not_available", InDesign is not running.

Give the AI your licence key only when it asks for it, and only in your own AI application. At the end, check for yourself what the configuration file contains – the AI shows it to you.