Free add-on, GPL like Blender itself

A bug tracker for your scene.

Red Pen adds a notes panel to Blender. Leave to-dos, bugs, and questions on the file you are working in, with real statuses rather than a text block you will never open again. Your .blend stays untouched: notes live in a small file beside it.

No objects added to your scene, no empties in the outliner, nothing saved into the .blend.

How it works

Install it like any add-on

It installs from a zip in Preferences and behaves like the add-ons you already use.

Install from disk

Preferences → Get Extensions → Install from Disk, pick the zip, enable it. Done, and it works offline from that moment on.

Open the N-panel

A Red Pen tab appears next to Item and Tool. Every note for the open file lives there.

Leave real notes

Note, Bug, To-do, or Question, each with Open, In Progress, or Resolved. Ctrl+Shift+N grabs a viewport snapshot onto the note, and it is in Blender's keymap so you can remap it.

Sync if you want to

Push notes to the Hub, a local board that sees all your projects. It is optional; the add-on is complete without it.

Respectful by design

Your scene stays exactly as you left it

Most note tools for Blender put objects in your scene and data in your file. Red Pen refuses to do either.

Nothing added to the scene

It creates no empties and no annotation objects. Your outliner looks the same with Red Pen as without it.

The .blend is never touched

Notes live in a JSON sidecar at .redpen/notes.json next to your .blend. File size, renders, and version history are unaffected.

A real lifecycle

Open, In Progress, Resolved, with note types and priorities. A high-priority note renders red in the viewport, so you see it without opening the panel. Reply threads are the one part of the note model that has not landed here yet.

Free and GPL

Licensed like Blender itself, and it will never grow a license key. The add-on is free, and so is the optional Hub.

Works offline

Nothing phones home, ever. The only network feature is the Hub sync, it is opt-in, and it talks to your own machine.

Two-way Hub sync

Push notes up, and pull board changes back down. Resolve something from the Hub and the file's notes update to match.

The red wire

Every file feeds the Hub

An asset, an environment, a rig: each file sends its notes to the Red Pen Hub, one local board that sees all of them.

hero-asset.blend

Blender add-on
Red Pen Hublocal board
hero-asset.blend3 open
kitchen_env.blend1 open
character_rig.blend2 open

The Hub also aggregates notes from the other Red Pen surfaces, so your portfolio site and your .blend files land on one board. Nothing in it counts projects, so the number you connect is up to your disk.

Put a red pen in the viewport

The add-on is free and always will be. GPL means it is yours the way Blender is yours. The Hub is free too, however many projects you point at it. There has never been a paid tier and there will not be one.

This page runs Red Pen too. The red button in the corner is the web version of the same idea.

FAQ

Questions

Does it put objects in my scene?

No. Nothing is added to your outliner or collections. Notes do get pinned to objects and drawn in the viewport as gizmos, at the exact point you clicked, but a gizmo is drawn rather than created. It is not an object, it is not in your scene data, and it is not in your renders.

Does it change my .blend file?

Never. Notes are stored in a small file beside your .blend. Keep the two together when you move projects around and the notes come along.

Is it really free? What's the catch?

Really free, and GPL like Blender itself, which also means an in-add-on paywall is off the table by design. There is no paid tier anywhere, in the add-on or the Hub. If it earns its keep you can back a release; nothing is gated behind it.

Can a teammate or client see my notes?

Not yet, not directly. The Hub is a board on your machine. It binds to localhost only and rejects anything else, so it is not something you can point a teammate at. The way to share today is the sidecar file itself: it sits next to the .blend, so committing it or sending it along carries the notes with the project. A shared multi-user Hub is on the roadmap.

Which Blender versions does it support?

It is built as a modern Blender extension for the 4.x series. Check the GitHub releases page for the exact minimum of the current build.