Reagent connects to REAPER through a Lua Script Bridge, giving you full control over your projects through natural language. This page covers what you can do and how it works.
How It Works
The Bridge is a script that runs inside REAPER and listens for commands from Reagent. When you send a message:
- Reagent figures out what you want to do
- Sends commands to REAPER through the Bridge
- REAPER executes the commands
- Results come back to Reagent
All operations are wrapped in undo blocks, so you can always undo any changes with Cmd/Ctrl + Z in REAPER.
Reagent has access to a set of specialized tools for interacting with REAPER. You don’t need to know the tool names—just describe what you want in plain language and Reagent picks the right tools automatically.
These tools read information from your project without making changes.
| Tool | What it does |
|---|
| Check Connection | Verifies REAPER is running and the bridge is active |
| Get Project State | Returns project overview: name, tempo, time signature, track/item counts, selection state |
| Get Tracks | Lists tracks with properties like name, color, mute/solo, volume, pan, and folder structure |
| Get Media Items | Returns detailed item information including position, length, takes, and fades |
| Get Markers & Regions | Lists all markers and regions with positions, names, and colors |
| Get Installed Plugins | Lists available FX (VST, VST3, AU, CLAP, JS) with type and manufacturer info |
| Get Media Source Info | Returns source file details: type, length, channels, sample rate, file size |
| Get Items by GUID | Fast lookup of specific items by their unique identifier |
| Tool | What it does |
|---|
| Execute ReaScript | Runs custom Lua code in REAPER for operations not covered by other tools |
| Trim Item Silence | Removes silent portions from items or splits at silence boundaries |
| Mark Peaks | Detects transients and amplitude peaks, places take markers |
| Replace Items | Swaps media items while handling track placement and alignment |
| Randomize Items | Applies pitch, volume, timing, and other randomization to items |
| Tool | What it does |
|---|
| Search REAPER API | Semantic search of ReaScript API docs to find functions and verify signatures |
Limitations
Some things aren’t possible through scripting:
- Operations requiring modal dialogs
- Real-time monitoring
If something isn’t possible, Reagent will explain why and suggest alternatives.
Modal dialogs or popups in REAPER will block Reagent until dismissed.
