Claude Desktop

The most polished MCP experience as of writing — native, GUI-driven, with a visible "tools" button per conversation.

Prerequisites

Claude Desktop installed (download)
A Transactional API token (create one from API Keys → New key, copy the tk_live_… value)

1. Open the config file

Claude Desktop reads its MCP config from a JSON file on disk.

macOS — ~/Library/Application Support/Claude/claude_desktop_config.json
Windows — %APPDATA%\Claude\claude_desktop_config.json
Linux — ~/.config/Claude/claude_desktop_config.json

If the file doesn't exist yet, create it (and the Claude folder if needed).

2. Add the Transactional server

Edit the config to include a mcpServers entry. If you already have other MCP servers, just add the transactional block alongside them.

{
  "mcpServers": {
    "transactional": {
      "url": "https://mcp.transactional.dev",
      "headers": {
        "Authorization": "Bearer tk_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
      }
    }
  }
}

Replace the token with yours.

3. Restart Claude Desktop

Fully quit (Cmd-Q on macOS, not just close the window) and reopen. MCP servers are discovered at startup.

4. Verify

In any conversation, click the 🛠 tools icon in the input bar. You should see a transactional entry with five tools:

list_documents
get_document
generate_pdf
list_folders
get_usage

Try this prompt:

"List my Transactional documents."

Claude will ask permission to call list_documents. Approve, and you'll see your templates inline.

Common issues

No transactional entry in the tools menu — The JSON didn't parse. Check for a trailing comma or a missing quote. Restart Claude after every edit.

"Connection failed" toast — Bad URL or the token isn't being sent. Verify the https:// prefix and that Authorization is exactly Bearer tk_live_… (one space).

Tools listed but every call returns unauthorized — Your token is revoked. Generate a new one in the dashboard and update the config.

Next steps

Run a first prompt →
MCP tools reference →