Model Context Protocol

InDesign MCP server

Sidekick is an MCP server for Adobe InDesign: it lets Claude (or any other AI assistant) work in your open documents.

In short

Sidekick speaks a protocol, not a product. That is why it is not tied to any one assistant.

What is MCP?

MCP is an open standard that lets AI assistants interact with external tools and applications. Instead of only chatting, an assistant can actually do things — read files, query databases, or in Sidekick's case, drive InDesign.

Think of it as a shared language between assistants and desktop applications. Sidekick implements an MCP server that turns what you ask for into InDesign commands.

What the server gives your assistant

An MCP server offers an assistant a set of tools. Sidekick's tools act on the documents you have open in InDesign:

  • Run code in InDesign. The assistant writes and runs scripts against InDesign's own scripting model, so anything a script can do — styles, frames, tables, threading, find and change, exports — it can do too.
  • See the page. Snapshots of a page, a spread or a single object let the assistant check its work the way you would: by looking at it.
  • Read the layout. Page sizes, margins and the area inside them, so new frames land where the document's grid says they should.
  • Measure type. Font metrics such as cap height and x-height, for alignment that is exact rather than approximate.
  • Keep what works. Sidekick Actions save a task as a reusable action you can run again from the chat or from a panel in InDesign.

How it connects

Sidekick has two parts. A plugin from Adobe Exchange runs inside InDesign; the MCP server runs on your computer, started by your assistant. They talk over a local connection that only accepts programs on the same machine; Sidekick does not send your documents to us. What the assistant reads of a document goes to the assistant you chose, as with anything else you share with it.

It works on macOS and Windows, with InDesign 2024 (version 19) and later.

What is MCPB?

MCPB (MCP Bundle) is Claude's native extension format for one-click installation of an MCP server. Double-click an .mcpb file and it is installed — no terminal required.

Not every MCP client supports MCPB yet. If yours does not, you can install Sidekick manually instead.

Clients that work

Sidekick works with any application that speaks MCP. These are the common ones.

Claude Desktop Anthropic's desktop app. Supports MCPB, so installing is a double-click. Recommended ChatGPT The ChatGPT desktop app and Codex CLI. Use the standalone installer. Cursor AI-powered code editor. Use the standalone installer. Devin Desktop The former Windsurf, with the Devin Local agent. Use the standalone installer. Continue Open-source AI code assistant for VS Code and JetBrains.

See the full list of MCP clients on the official MCP site.