Personal Agent Bench

Is Meta Muse open source? What is open, and what is not

Is Meta Muse open source? No. The Muse agent, the apps you reach it through and the Linux machine it runs on in Meta's cloud are all closed, and the model Meta says powers it, Muse Spark, has no public weights. But "Meta Muse open source" is not an empty search either, because Meta has opened two things with the Muse name on them: a kit for building small devices that talk to Muse, released on 2 October 2026, and a 30-billion-parameter model called Muse Glimmer, released with open weights in August. Neither one lets you run Muse yourself. This page goes through each layer, says where each answer comes from, and points to the two open-source projects that were built to be what Muse is not.

  • The Muse agent, its apps and its per-user cloud VM are closed. Meta has described the design in public, and our teardown examined it from outside, but no code is published.
  • Muse Spark, the model behind Muse, is offered through APIs. We found no Spark weights on Hugging Face as of 12 October 2026.
  • Muse Glimmer 30B is open-weight under Apache 2.0, distilled from Muse Spark and built to run on your own hardware. It is a separate model, not the one Meta says Muse runs on.
  • Muse Gadgets is open source under Apache 2.0, but every gadget needs a token from Meta to pair, so it extends Muse rather than replacing it.

Is Meta Muse open source? The answer, layer by layer

"Muse" means four different things depending on who is asking, and each has its own answer.

  • The app. iOS, Android, the web, WhatsApp, and since 17 September a Mac app. Closed.
  • The agent and its machine. Each user gets a Linux virtual machine in Meta's cloud, with the agent, its tools and a gatekeeper Meta calls Sentinel running on it. Closed. Meta has published a detailed account of the design but not the code.
  • The model. Meta's launch post says Muse is "powered by Muse Spark," and Meta's security write-up names Muse Spark 1.3. No public weights.
  • The devices around it. The Muse Gadgets SDK is open source under Apache 2.0.

And separately, there is an open-weight model in the same family, Muse Glimmer 30B, which runs on your own hardware but is not the model the Muse product names.

So the short version is: what you would need to run Muse is closed, and what is open sits around the edges of it.

Meta Muse's agent and VM: closed, but described in public

The part that makes Muse Muse is the agent: one long conversation, memory kept as files, tools it can call, and a gate in front of anything that leaves the machine. All of it runs on a virtual machine Meta provisions for each user, which Meta calls Muse Secure VM. None of that runtime is published as source.

What Meta has published is an unusually detailed description. The security write-up explains that a second agent, Sentinel, is the only thing that can approve a connector action or let network traffic out; that the agent works with stand-in credentials that are swapped for real ones at the network edge after approval; and that approval requests go straight to your app rather than through the conversation. It also says that, for now, staff access to your data is restricted by policy rather than made impossible, and that an encrypted Muse Confidential VM is planned for later.

A published design is not open source. You cannot read the code that enforces it, run it yourself, or check that the build you are talking to matches the description. Our Muse teardown got as far as the structure of the requests and the permission sheet of 246 methods, and lists what it could not reach, starting with every request the runtime actually sent to the model.

Muse Spark: the model Meta Muse runs on, and why it is not open source

Muse Spark is what Meta's launch post calls its "most capable model to date," and it is the model Meta names for Muse in both its launch post and its security write-up. You can call Spark models through APIs. OpenRouter's Meta page listed Muse Spark 1.2 and 1.3 on 12 October 2026, priced per token like any hosted model.

What you cannot do is download Spark. A search of Hugging Face on 12 October found no Muse Spark weights published by Meta, only unrelated projects that borrowed the name. If you have seen "muse spark open source" in a headline, it is almost certainly about one of the two releases below, not Spark itself.

That matters for anyone hoping to reproduce Muse. Even with the agent's design written up in detail, the model doing the reasoning would be a different one.

Muse Glimmer: the open-weight model in the Meta Muse family

Muse Glimmer 30B is the one genuinely open model with Muse in its name. Meta Superintelligence Labs published it on Hugging Face on 9 August 2026 under the Apache 2.0 licence, with no gate on downloading it.

The model card describes a dense model of about 29.6 billion parameters with a built-in image encoder, distilled from Muse Spark and "purpose-built for autonomous agentic tasks on consumer hardware." Quantised to around 4 bits, the language model fits in under 20 GB, and the card lists target setups from 24 GB to 64 GB of video memory. It names tool use, failure recovery and multi-step planning as what it was trained for, and says it works with open agent frameworks such as OpenClaw and Hermes Agent.

Two cautions. First, Glimmer is not what Meta says Muse runs on; the launch post and security write-up both name Spark. Running Glimmer at home gives you a capable open model from the same lab, not a copy of Muse. Second, "open weights" is not the same as open training. The card says the training data includes publicly available data, licensed data and information from Meta's products and services, and none of that data is released.

Glimmer is still the most useful answer to the question for many people. If what you want is a Meta-trained model for agent work that you control, this is it. Our where it runs page sets the hosted agents beside the ones you run yourself, which is where a model like this would go.

Muse Gadgets: the open-source part of Meta Muse itself

The release that triggered most of the "Meta Muse open source" headlines is Muse Gadgets, published on GitHub under Meta's facebookincubator organisation on 2 October 2026.

It contains two device SDKs. One is firmware for off-the-shelf ESP32 boards, so a small board with a screen, a speaker or some sensors can show images, play audio or report readings to Muse. The other is a service for a Raspberry Pi or any spare Linux box, so you can add your own commands and let Muse run chores on it. Gadgets pair with the Muse app on iOS and Android once you switch on a developer mode in its device settings. Meta's README is cheerful about the risks and lists bricked boards and voided warranties among the side effects.

The code is under Apache 2.0, with a few third-party files under their own licences and one exception: the animated avatar is not covered. The bigger limit is in the pairing step. Every gadget needs an SDK token from Meta and is subject to Meta's separate Gadget SDK terms. So Muse Gadgets is open source in the sense that you can read and change the device side. It does not make Muse portable: a gadget with no Muse account behind it has nothing to talk to.

Open-source alternatives to Meta Muse

If the question behind the search is "can I have something like Muse that I run myself," there are two projects built specifically as an answer, and they made opposite choices.

OpenMuse, from CopilotKit, was published on 15 September under the MIT licence. It runs on a server you control, with a persistent browser and an optional Linux workspace, and the apps are windows onto that server. We read its source rather than probing it. The catch we found is that conversation persistence depends on a hosted CopilotKit service the MIT licence does not cover.

nanoMuse, from a small team at Zhejiang University, went up on GitHub in late September under GPL-3.0-or-later. It puts a whole agent on each of your devices instead of one agent on a server, and on Android and a computer it can operate other apps through their screens, which Muse cannot. Its paper is frank that it lacks Muse's per-user VM and the hard security boundary that comes with it.

Neither is affiliated with Meta, neither has been through our exam, and both are young. Each has a page here that sets out what is public and what is still unknown.

What an open Meta Muse would change

The case for openness here is not abstract. A personal agent holds your inbox, your calendar and a written profile of you, and acts on them while you are away. The questions people most want answered about such a thing, what exactly it sends, what it keeps, and whether the gate in front of a payment really holds, are the ones that are hardest to settle from outside.

Our own work shows the gap. On Muse we could describe the shape of the request and the permission sheet, but we never saw a request leave the machine. On OpenMuse we could read every line that decides where your data goes. Neither is a verdict on which is safer, but only one of them can be checked by anyone who cares to look.

Our teardown called Muse the most generous architecture on our scorecard, and Meta's security write-up is more detailed than most vendors publish. Opening the device kit and a smaller model are real steps. The agent you actually talk to, and the machine it runs on, remain Meta's.

FAQ

Is Meta Muse open source? No. The Muse agent, its apps and the cloud VM it runs on are closed, and the Muse Spark model has no public weights. Meta has open-sourced the Muse Gadgets SDK and released the Muse Glimmer 30B model with open weights.

Is Muse Spark open source? No. Muse Spark is available through hosted APIs, but as of 12 October 2026 Meta had not published its weights. Muse Glimmer 30B, which is distilled from Spark, is the open-weight one.

What is Muse Glimmer? A roughly 30-billion-parameter open-weight model from Meta Superintelligence Labs, released in August 2026 under Apache 2.0, built for agent tasks and designed to run on consumer hardware. It is not the model Meta says powers the Muse app.

What are Muse Gadgets? An open-source SDK, released on 2 October 2026, for building small devices on ESP32 boards or Linux computers that pair with your Muse. Each gadget needs a token from Meta to pair.

Can I self-host Meta Muse? No. The agent only runs on Meta's infrastructure. If you want something in the same shape that you run yourself, OpenMuse and nanoMuse are the two open-source projects built for that.

Is OpenMuse made by Meta? No. OpenMuse is from CopilotKit and nanoMuse is from an independent university team. Both borrowed the name because Muse defined the kind of product they are building.