APID ToolAssistant for Adobe InDesign

Runtime Environment for InDesign Plugin Development

APID ToolAssistant is a runtime dependency: a C++ plug-in that other InDesign plug-ins rely on. It adds no functionality to InDesign on its own (except a single API configuration menu) and does no work by itself.

Do you need to install it?

Install it manually from this page whenever a plug-in needs it to be installed. The main plug-in’s own product page will tell you if that’s the case.

Plug-ins that need APID ToolAssistant are currently not installed by way of PluginInstaller. You need to manually drag items into InDesign’s Plug-Ins folder yourself.

  1. APID ToolAssistant: 2 plug-ins, in total 2 items on macOS, 4 items on Windows (steps below).

  2. The dependent plug-in itself: its .spln file, plus any helper files that ship with it. See that plug-in’s own page.

Currently, PluginInstaller’s only task regarding APID-dependent plug-ins is licensing and activation (see Licensing below). It does not copy plug-in files.

On the other hand, PluginInstaller will properly install the Rorohiko enhancements that do not need APID ToolAssistant (TextExporter, GryperLink, Style-O-Matic, …).

What APID ToolAssistant provides

  • Extended ExtendScript / scripting APIs for dependent plug-ins

  • Extra UI and document-manipulation APIs

  • Licensing and activation services for plug-ins that use them

System requirements

  • InDesign 2025 or higher (see Legacy versions for older releases)

  • macOS or Windows

  • Administrator rights: the InDesign Plug-Ins folder lives inside the application folder

  • InDesign must be fully quit during installation

Installation

  1. Quit InDesign.

  2. Download the version matching your platform and InDesign version from the table below.

  3. Unzip it. The contents may sit inside an extra nested folder (common on Windows). Keep opening folders until you reach the plug-in items themselves.

    You are looking for 2 plug-ins:

    • macOS: 2 files ending in .InDesignPlugin: 2 items total.

    • Windows: 2 files ending in .pln, each with a matching resources subfolder: 4 items total (2 files + 2 folders).

  4. Copy every one of those items into InDesign’s Plug-Ins folder (creating a Rorohiko subfolder inside Plug-Ins is tidy but optional):

    • macOS: /Applications/Adobe InDesign 2026/Plug-Ins/

    • Windows: C:\Program Files\Adobe\Adobe InDesign 2026\Plug-Ins\

    Other InDesign versions use  similar names, with just the year changed. Authenticate as an administrator when prompted.

  5. Launch InDesign.

  6. Verify: an API menu appears in the InDesign menu bar. If it does not, the components are in the wrong folder or the wrong build was used.

Do I need an APID ToolAssistant license?

It depends on who made the plug-in that uses APID ToolAssistant:

The plug-in you are running APID ToolAssistant license?
A Rorohiko plug-in (TextStitch, LayerLifter, FrameReporter, …) No — never. The Rorohiko plug-in may need its own license, bought and managed via PluginInstaller, but APID ToolAssistant itself stays free forever.
A non-Rorohiko plug-in — a third party’s, or one you built yourself with the APID Toolkit Yes, once the 20-day trial ends. Without it, that plug-in stops running.

APID ToolAssistant starts with a 20-day trial, no license required. The trial exists so you can evaluate non-Rorohiko plug-ins (including your own during development). When the trial ends:

  • Rorohiko plug-ins keep working: trial expiry does not touch them.

  • Non-Rorohiko plug-ins stop until an APID ToolAssistant license is active.

License: $25 USD per seat, per year, renewed annually.

To buy a license for APID ToolAssistant:

  1. Install and open PluginInstaller.

  2. Switch to Available Software and type ‘APID’ in the search field.

  3. Select APID ToolAssistant.

  4. Choose Buy from the ⋯ menu and follow the checkout.

Updating

APID ToolAssistant does not update itself. To move to a newer build, re-download from this page and copy the items over the old ones (quit InDesign first).

Downloads

Current builds: 1.0.78:

Platform InDesign Download
macOS 2026 APIDToolAssistant_Mac_2026.1.0.78.zip
macOS 2025 APIDToolAssistant_Mac_2025.1.0.78.zip
Windows 2026 APIDToolAssistant_Win_2026.1.0.78.zip
Windows 2025 APIDToolAssistant_Win_2025.1.0.78.zip

Legacy Versions

https://rorohiko.com/wordpress/indesign-downloads/apid-toolassistant/

  • Available for InDesign 2024 and older
  • No longer updated or supported
  • Use only if current version incompatible