loopcut
The connector for Loopcut, an open-source AI agent inside Blender: cloud render,
assets, images, 3D models, motion and audio for Claude Code, Codex, Cursor, Claude Desktop and the shell, and
as a hosted connector for claude.ai and ChatGPT. Render .blend files on cloud RTX 4090s, search free asset
libraries, make and edit images, turn images into 3D models, remesh meshes, rig characters, make sound effects and voice
lines, and turn a video or a sentence into character animation on your own rig. Results come back as files the agent imports with Blender's Python. Everything is paid from your
Loopcut account's credits. You don't need the Loopcut app; any Blender install packs the scene.
It's one MCP server plus a CLI with the same verbs. The tools come from Loopcut's catalog, so a cloud tool
that opens on Loopcut shows up without a new release.
Results are files the next tool takes: a generated image as image_to_3d's image, a model as remesh's
model, a rendered frame as image_edit's image. With a budget from you, the agent passes max_credits to a
paid tool, which starts a quote within it at once instead of returning it for job_start.
A character from a photo, rigged and animated: image_edit the photo into a T-pose with separated fingers,
image_to_3d from that with topology: "quads", import it and save the .blend, auto_rig it (20 credits),
then motion_from_text and motion_apply. auto_rig takes humanoids with clear arms, legs and fingers, up to
100,000 triangles; a rig that can't be bound is refunded automatically.
Motion
Two motion tools, with a free local tool to use their results:
motion.bvh is a rig-neutral SOMA 77-joint skeleton (standing T-pose rest, centimetres, Y up, 30 fps).
The connector measures the clip's length itself (MP4 and MOV from the file header, WebM with ffprobe
when it's installed) because the quote holds the seconds captured. target_armature and in_place on a
motion tool are kept on your machine for motion_apply and never sent to Loopcut. job_status returns
the result with three ways to use it: motion_apply (or loopcut motion-apply) for a saved .blend,
a short Python snippet for a Blender that's already open (for example through another Blender MCP),
and Blender's plain BVH import. The retargeting is the Loopcut add-on's own, so results match the app.
With no-generation on, motion_from_video stays available (it records the user's own performance) and
motion_from_text is hidden.
Price. 1 credit = $0.01. Every paid tool quotes first, for free, and the quote is the most a job can
cost. Rendering costs 5 credits per GPU-minute on an RTX 4090 with a one-minute minimum; the other prices
are on loopcut.org/pricing. Asset search, quotes, packing and the render QA
report are free. Failed jobs are refunded. New accounts start with 100 credits.
Install
You need uv (it provides Python 3.10+), and Blender if you render or apply a
motion. To get uv: brew install uv or curl -LsSf https://astral.sh/uv/install.sh | sh on macOS and Linux,
powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex" on Windows.
claude.ai, ChatGPT and Claude Desktop, nothing to install: add https://loopcut.org/mcp as a connector and
sign in with Loopcut. In Claude: Customize → Connectors → Add custom connector. In ChatGPT: chatgpt.com/plugins →
+ → Add custom MCP server (custom servers with paid tools need a Business, Enterprise or Edu workspace
until Loopcut is in ChatGPT's plugin directory). The hosted connector has asset search, images, 3D models,
remeshing, motion from text, sound, voice and rendering from a script, and returns download links; one tool's
result feeds the next by its job:<job_id>/<name> ref. Rendering your own .blend and motion from a video
need the plugin below, because they read files on your computer.
Claude Code (plugin, which includes a skill that teaches the agent the tools and the habits that save
credits)
On Claude Code before 2.1.275, run /plugin marketplace add loopcut-ai/loopcut and then
/plugin install loopcut@loopcut. Or add only the MCP server:
Codex (plugin, with the same skill)
Or add only the MCP server:
Every tool call returns within 50 s, under Codex's default 60 s tool timeout; long work carries on between
calls. Both plugins start the server with uvx loopcut==<release> mcp, pinned to the release they ship with; the
package has no dependencies beyond Python.
Cursor, VS Code, Claude Desktop and other MCP clients
Apps opened from the Dock or Start menu may not see your shell's PATH. If the server doesn't start, use
the full path from which uvx as command.
The first call opens a browser to sign in, and the key is kept where only you can read it. Without a
browser (over SSH, say), the call returns the link for you to open. LOOPCUT_API_KEY skips all of this.
CLI
Install the command with uv tool install loopcut, or run any command without installing as uvx loopcut ….
run and render quote, then start only with --yes, under --max-credits N, or after you answer the
prompt. run of a motion tool with --blend also puts the motion on that scene's rig; motion-apply
saves over --blend (Blender keeps the previous file as .blend1) unless you give --out. Results print as JSON on stdout; progress goes to stderr. In CI, create a key on
loopcut.org/account and set LOOPCUT_API_KEY.
Settings
Private mode and no-generation. These account settings apply here too. Private mode (on by default on
paid plans) refuses tools whose provider may train on what it receives; today that is sound effects.
No-generation hides and refuses the generative tools. Change them in the Loopcut app or with
loopcut settings.
How it works
- Quote. Every tool goes through the same job API the Loopcut add-on uses. A quote prices the exact
request and lasts ten minutes; an expired one is renewed at start, and the job goes ahead only if the
price didn't change. Starting the same quote twice returns the same job.
- Files in. File inputs are local paths. They're checked (type and size), addressed by SHA-256, and
only uploaded if the cloud doesn't already have them, straight to storage with presigned URLs. Big
files go in parts, each retried on its own.
- Render packing. A background Blender (
-b --factory-startup --disable-autoexec) opens the saved
.blend and runs the Loopcut add-on's own collector (addon/bundles.py, vendored). It copies every
texture, library, cache and sequencer file into a bundle with relative paths. That Blender gets a
private config folder and none of your environment's keys. The cloud never runs Python from your file,
and the renderer has no internet access.
- Files out. Results are checked against their hashes and saved into
loopcut_renders/<job_id>/
next to the .blend for a render, and loopcut_outputs/<job_id>/ in the working folder for everything
else (or out_dir). The working folder is the client's workspace root when it shares one; Codex starts
plugin servers in the plugin's own folder, so there results go under your home folder instead. A
render's QA report flags black, white, flat and transparent frames, fireflies, duplicate frames and
exposure jumps.
- Motion onto a rig.
motion_apply starts the same kind of background Blender on your saved .blend
and runs the add-on's retargeter (addon/motion_retarget.py, vendored) through
loopcut/motion_blender.py: one whole-body rest alignment, limb-only direction alignment for A-pose
rigs, the pelvis path scaled by leg length from the character's own standing height, and keys written
parent first. A previous action on the rig is kept in a muted NLA track. Nothing leaves your machine and it
costs nothing.
- Rigging.
auto_rig runs the add-on's rigging code (addon/autorig.py and rig_*.py, vendored) in a
background Blender through loopcut/rig_blender.py, once on each side of the cloud job: first it checks the
named meshes and writes the upload (the meshes as a GLB and a rig task with their fingerprints) to the state
folder, without changing the .blend; after the job it checks the character is unchanged, verifies the
returned skeleton and weights against what was sent, binds them to the original meshes and saves.
If the catalog can't be read at startup, the server uses the last catalog it read from that service, then
the snapshot in src/loopcut/catalog.json.
What it runs and connects to. uv, which provides Python (and downloads it if needed); your Blender,
headless, only to pack a scene for render_quote, to apply a motion with motion_apply and to check and bind a rig for auto_rig; ffprobe, if
installed, only to measure a WebM clip; and your browser, only to open the Loopcut sign-in
page. It connects to loopcut.org (the catalog, sign-in and job API) and to the presigned storage URLs
that API hands out for uploads and downloads. It sends no analytics.
Privacy Policy
Loopcut's privacy policy is at loopcut.org/privacy. For this connector:
- What it sends. The Loopcut key on every request, with the client's name and version. For a render,
the packed scene: the saved
.blend and every texture, library and cache it uses. For other tools, the
inputs you or the agent give (prompts, settings) and the files named as inputs (images, meshes, videos).
It reads nothing else from your machine: no other files, no environment keys besides LOOPCUT_API_KEY,
no open Blender session. motion_apply opens and saves the .blend you name on your machine only, and
target_armature and in_place stay local too. For auto_rig it sends the named meshes (as a GLB) and their
fingerprints, not the .blend, and binds the result on your machine.
- Where it's stored. Loopcut's database (Supabase, US) holds your account, quotes and jobs; uploaded
files and results are kept in Cloudflare R2.
- Third parties. Each job goes only to the provider that runs it: today OpenAI, fal and the model
developers it runs (Deemos for Rodin, Tripo), Google Cloud, ElevenLabs and RunPod. Providers' own
retention terms are on the privacy page. Private mode, on by default for paid plans, refuses tools whose
provider may train on what it receives (today, sound effects).
- Retention. Uploaded files are deleted 7 days after their last use and results 30 days after theirs.
Account and billing records are kept while the account exists. Results you download are ordinary files
on your machine.
- On your machine. The key, quotes, jobs and the last tool catalog are kept in
~/.config/loopcut-connector, readable only by you. loopcut logout removes the key.
- Contact. [email protected], also for exporting or deleting your account data.
Development
The end-to-end tests run against Loopcut's contract mock, which lives in the service repository; they're
skipped here. addon/VENDORED.md explains how the add-on copies are kept in sync.
Released under the GPL-3.0-or-later. Loopcut is an independent project; Blender is a trademark of the
Blender Foundation.