InDesign UXP Server

Forked from zachshallbetter/indesign-mcp-server — rewritten to use Adobe's UXP plugin platform instead of AppleScript.

A Model Context Protocol (MCP) server that gives AI assistants direct, native control over Adobe InDesign via a UXP plugin bridge. ~130 tools covering the full InDesign feature set — documents, pages, text, graphics, styles, master spreads, books, and export.

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Why UXP vs AppleScript

This server is a ground-up rewrite of the AppleScript-based indesign-mcp-server. The execution model is fundamentally different.

	AppleScript (original)	UXP (this fork)
Platform	macOS only	macOS + Windows
Execution path	Node → temp JSX file → AppleScript → InDesign	Node → HTTP → WebSocket → InDesign plugin
Speed	Slow — 3 hops, disk write per call	Fast — direct in-process call
Reliability	Flaky — breaks if InDesign loses focus or system dialogs appear	Stable — not affected by focus or system state
Return values	Strings only (last evaluated expression)	Full structured JSON objects
JS version	ExtendScript (ES3 — no const, arrow functions, or async/await)	Modern JS (ES2015+ — async/await, destructuring, arrow functions)
Error messages	Cryptic AppleScript/OSA errors	Structured JSON with clear error strings
String handling	Manual escapeJsxString() for every value	JSON.stringify() throughout — safe and simple
Enums	Magic strings like 'PDF_TYPE'	Typed enums via require('indesign').ExportFormat.pdfType
Async support	Not supported — synchronous only	Native await (e.g. await doc.filePath)
Permissions	macOS Automation + Accessibility in System Settings	None beyond InDesign plugin install
Future-proofing	❌ Adobe is deprecating ExtendScript/CEP	✅ UXP is Adobe's official modern platform

The short version: The AppleScript version puppets InDesign from the outside via macOS automation, writing temp files and hoping nothing interrupts the chain. This version runs inside InDesign as a first-class plugin — faster, more reliable, cross-platform, and built on the platform Adobe is investing in going forward.

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How It Works

Claude / MCP Client
       │
       ▼
  MCP Server (Node.js)
       │  POST /execute
       ▼
  Bridge HTTP Server (port 3000)
       │  WebSocket
       ▼
  UXP Plugin (inside InDesign)
       │  runs as async IIFE with `app` in scope
       ▼
  InDesign DOM

The UXP plugin maintains a persistent WebSocket connection to the bridge. When a tool is called, the handler sends a JS code string to the bridge, which forwards it to the plugin. The plugin runs it as new Function('app', 'return (async () => { CODE })()') and returns the result as JSON.

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Prerequisites

• Adobe InDesign 2024+ (UXP plugin support required)
• Node.js 18+
• macOS or Windows

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Setup

1. Install the UXP Plugin

Load the plugin via the UXP Developer Tool or InDesign's plugin manager:

plugin/
├── index.js        # Plugin entry point + WebSocket client
└── manifest.json   # Plugin manifest

2. Start the Bridge

# Kill any existing bridge processes
lsof -ti:3001 | xargs kill 2>/dev/null
lsof -ti:3000 | xargs kill 2>/dev/null

# Start the bridge
cd bridge && node server.js

3. Connect the Plugin

In InDesign: Window → Plugins → InDesign Bridge

The panel should show: Connected to bridge ✓

4. Start the MCP Server

npm install
npm start

5. Configure Claude

Add to ~/.claude.json (or your MCP client config):

{
  "mcpServers": {
    "indesign": {
      "command": "node",
      "args": ["/path/to/indesign-uxp-server/src/index.js"]
    }
  }
}

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Testing

# Quick sanity check (4 core tools)
node tests/test-uxp-handlers.js

# Full suite (27 tests across all handler categories)
node tests/test-all-handlers.js

Current status: 27/27 passing across all handler categories.

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Tools

Documents

create_document open_document save_document close_document get_document_info get_document_preferences set_document_preferences get_document_elements get_document_styles get_document_colors get_document_layers get_document_stories get_document_hyperlinks create_document_hyperlink get_document_sections create_document_section get_document_grid_settings set_document_grid_settings get_document_layout_preferences set_document_layout_preferences get_document_xml_structure export_document_xml preflight_document validate_document cleanup_document data_merge save_document_to_cloud open_cloud_document view_document

Pages & Spreads

add_page delete_page duplicate_page move_page get_page_info set_page_properties adjust_page_layout resize_page reframe_page navigate_to_page select_page zoom_to_page set_page_background create_page_guides place_file_on_page place_xml_on_page get_page_content_summary snapshot_page_layout delete_page_layout_snapshot delete_all_page_layout_snapshots list_spreads get_spread_info duplicate_spread move_spread delete_spread set_spread_properties create_spread_guides place_file_on_spread place_xml_on_spread select_spread get_spread_content_summary

Text & Tables

create_text_frame edit_text_frame create_table populate_table find_replace_text find_text_in_document

Styles & Colors

create_paragraph_style apply_paragraph_style create_character_style list_styles create_color_swatch list_color_swatches apply_color create_object_style list_object_styles apply_object_style

Graphics & Shapes

place_image get_image_info create_rectangle create_ellipse create_polygon

Layers

create_layer set_active_layer list_layers organize_document_layers

Page Items

get_page_item_info select_page_item move_page_item resize_page_item set_page_item_properties duplicate_page_item delete_page_item list_page_items

Groups

create_group create_group_from_items ungroup get_group_info add_item_to_group remove_item_from_group list_groups set_group_properties

Master Spreads

create_master_spread list_master_spreads delete_master_spread duplicate_master_spread apply_master_spread get_master_spread_info create_master_text_frame create_master_rectangle create_master_guides detach_master_items remove_master_override

Export & Output

export_pdf export_images export_epub package_document

Books

create_book open_book list_books add_document_to_book synchronize_book repaginate_book export_book package_book preflight_book print_book get_book_info set_book_properties update_all_cross_references update_all_numbers update_chapter_and_paragraph_numbers

Utility

execute_indesign_code get_session_info clear_session help

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Architecture

src/
├── core/
│   ├── InDesignMCPServer.js    # MCP server, tool registration
│   ├── scriptExecutor.js       # executeViaUXP() — POSTs to bridge
│   └── sessionManager.js       # Page dimension tracking, smart positioning
├── handlers/
│   ├── documentHandlers.js
│   ├── pageHandlers.js
│   ├── textHandlers.js
│   ├── styleHandlers.js
│   ├── graphicsHandlers.js
│   ├── masterSpreadHandlers.js
│   ├── pageItemHandlers.js
│   ├── groupHandlers.js
│   ├── bookHandlers.js
│   ├── exportHandlers.js
│   └── utilityHandlers.js
├── types/                      # MCP tool schema definitions
└── utils/stringUtils.js

bridge/
└── server.js                   # HTTP (port 3000) + WebSocket (port 3001) bridge

plugin/
├── index.js                    # UXP plugin — runs code inside InDesign
└── manifest.json

tests/
├── test-uxp-handlers.js        # 4 core handler tests
└── test-all-handlers.js        # 27-test comprehensive suite

Key UXP API Notes

• InDesign collections require .item(n) — bracket access [n] returns undefined
• doc.filePath is async — always await it in UXP code
• exportFile(format, path) — format arg is first (same as ExtendScript)
• Enums via require('indesign'): ExportFormat.pdfType, ColorModel.process, etc.
• Path strings work directly for place() and exportFile() — no UXP storage API needed
• Code runs as async IIFE — use return to return values, await works natively

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License

MIT