1# Muse Code
2
3Muse Code is a beta integration and is disabled by default. Install
4[Muse Code](https://dev.meta.ai/docs/muse-code) on the machine hosting your
5environment, then run `muse login` as the account that runs T3 Code.
6
7Open **Settings → Providers** in the web or desktop app, select the environment,
8and enable **Muse Code**. Set **Binary path** if Muse is not on the host's `PATH`.
9Refresh provider status after installation or login, then select Muse in a
10thread's model picker.
11
12Provider status does not check your login. If you are signed out, messages
13fail until you run `muse login` on the host.
14
15## Sign-in and API keys
16
17T3 Code ignores a `META_API_KEY` that the T3 server inherits from its own
18environment, so Muse uses the credential saved on the host by `muse login`. To
19use an API key instead, add `META_API_KEY` to the Muse instance's environment
20variables in **Settings → Providers**. Muse gives that key priority over the
21saved login.
22
23## Remote access and instances
24
25Connect from web, desktop, or mobile through [remote access](./remote-access.md).
26Muse uses the selected environment's files and login; connecting devices do not
27need Muse installed. Install and sign in separately on each host where you want
28Muse to run.
29
30Add a provider instance for a separate configuration. Instances on the same host
31share its Muse login; give an instance its own `META_API_KEY` to bill it
32separately. Existing conversations retain their instance when its model catalog
33becomes unavailable.
34
35## Models
36
37Models and reasoning choices come from Muse on the selected host. After changing
38Muse configuration, refresh provider status in **Settings → Providers**. On
39mobile, pull down in thread settings to refresh models. If a saved model becomes
40unavailable, select an available model before sending another message.
41
42Muse can list models that your account cannot use. If a message fails with
43"does not exist or you lack access", pick another model, or add one your account
44can use under **Custom models** in the instance settings.
45
46## Permissions and limitations
47
48Muse offers two [permission modes](./permission-modes.md): **Supervised** asks
49before commands and edits, and **Full access** runs them without asking. Muse has
50no equivalent of **Auto-accept edits** or **Auto**, so they are not offered. Muse
51does not offer a separate Plan mode in T3 Code.
52
53Muse can use T3 Code's tools. If Muse cannot reach them, the turn continues
54without them. Switching providers can pass conversation context as a handoff.
55
56Muse skills do not appear in the composer's `$` menu. Muse still loads them
57itself. Manage them with `muse skills` on the host.
58
59Forking a Muse conversation starts a new session with a copy of the conversation
60context. Conversation rewind is unavailable.
61
62Install Muse and sign in on the host; in-app installation and sign-in are not
63available. Updates can run from **Settings → Providers** when T3 Code recognizes
64the Muse launcher; otherwise update Muse on that host manually.
65
66To stop using Muse in an environment, disable it in **Settings → Providers**.
67This keeps the host's Muse login, thread history, and workspace files.