PDF Merger MCP Server

An MCP (Model Context Protocol) server that exposes the PDF Merger App as a set of tools any MCP-compatible LLM client can use to upload, arrange, merge, and download PDFs.

Tools

Tool	Description
pdf_merger_upload_pdfs	Upload one or more PDF files from disk to the merger service
pdf_merger_remove_file	Remove a file from an upload session
pdf_merger_merge	Merge uploaded PDFs in a specified order
pdf_merger_get_download_url	Build a one-time download URL for the merged result

Quick Start

# Install dependencies
npm install

# Build
npm run build

# Run (stdio transport — default)
PDF_MERGER_API_URL=http://localhost:3000 npm start

# Run (HTTP transport for remote access)
TRANSPORT=http PORT=4000 PDF_MERGER_API_URL=http://localhost:3000 npm start

Environment Variables

Variable	Default	Description
PDF_MERGER_API_URL	http://localhost:3000	Base URL of the PDF Merger App API
TRANSPORT	stdio	Transport mode: stdio or http
PORT	4000	HTTP server port (only when TRANSPORT=http)

Claude Desktop Configuration

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "pdf-merger": {
      "command": "node",
      "args": ["/path/to/pdf-merger-mcp-server/dist/index.js"],
      "env": {
        "PDF_MERGER_API_URL": "https://your-merger-app.vercel.app"
      }
    }
  }
}

Typical Workflow

1. Upload PDFs → returns session_id + file IDs
2. Remove unwanted files (optional)
3. Merge with desired file order → returns one-time download token
4. Download using the token URL

Architecture

LLM Client ──MCP──▶ pdf-merger-mcp-server ──HTTP──▶ PDF Merger App (Express)
                     (stdio or HTTP)                  (Vercel Blob + pdf-lib)

Development

npm run dev    # Auto-reload via tsx watch
npm run build  # Compile TypeScript → dist/
npm run clean  # Remove dist/