Everything between the request and the pull request.

Give every task its own conversation.

Open a folder on your Mac as a project and start a chat for each feature or fix. Name and pin chats, filter the sidebar, and find your drafts and history where you left them after a relaunch.

Jump anywhere with ⌘K.

The command bar runs any command and finds settings, guide topics and past messages.

Home shows what needs you.

Approvals waiting on you, plans ready to review, failed checks and running work appear in one place. Each item opens the chat it came from.

Start from a suggestion.

An empty chat offers starter tasks. They fill the composer and wait for you to send.

Make each project easy to spot.

Give a project an emoji and a colour.

Plan before a file changes.

Switch the composer to Plan and Muse works out the approach without editing your project. Read the plan, then approve it to build, ask for changes, or discard it.

An approved plan waits for you.

If an approved plan can’t start (the connection drops, or the folder moved), it stays in the chat with Retry and Inspect.

Keep the work together.

Open a task with /task and its plan, changes, checks and checkpoints collect in the inspector. Set a goal, and mark it accepted when the work is done.

Choose the model and effort.

Set the model and reasoning effort per chat or per project, from the models your Muse account offers.

Models from your Muse account

See each step as it runs.

A turn lists its steps while it works. Expand any step for detail, or collapse the whole turn when it’s done.

Approve commands with the full picture.

When Muse asks to run something, Thalia shows the whole command, with hidden characters made visible, before Allow is available. Decide in the chat, from Home, or with ⇧⌘A and ⇧⌘D.

Steer, stop or answer mid-turn.

Send a new instruction while Muse is working, stop the turn with ⇧⌘., or choose an answer when Muse asks you a question. Edit and resend an earlier request, or retry a reply.

See the helper agents Muse starts.

When Muse hands part of a task to helper agents, the Agents screen shows each one: what it’s doing, what it returned, and the worktree it works in. You can message a helper or stop it.

When Muse delegates

Coordinate sessions in one project.

Sessions shows other Muse sessions working in the same project, a shared task board, and messages between sessions. Claims on the board are advisory; they don’t lock files.

Several Muse CLI sessions in one project

Review the change, then approve exactly that.

Changes lists every file that differs from your last commit, and Review shows each file’s diff. When you approve, Thalia records the exact snapshot. If a file changes afterward, the approval is withdrawn until you review again.

In Git projects

Send review notes back to Muse.

Write what should change and send it to the chat the work came from (⌥⌘↩).

Run your checks next to the diff.

Save your project’s verification command once, run it with ⇧⌘T, and see pass or fail beside the changes. The result is marked stale when files change. When a check fails, ask Muse to fix it with the failure attached.

Rewind with a preview first.

Capture a checkpoint. Before a restore writes anything, Thalia shows which files it will put back and which it will move to Thalia’s trash. It also saves a checkpoint of the current files first, so you can undo the rewind.

In Git projects

Preview a static site.

Open a preview inside Thalia. The preview runs from an isolated copy, not your project folder.

Static sites with index.html at the root

A separate checkout for separate work.

Create a Git worktree from the Agents screen, open a chat in it, and remove it when you’re done.

In Git projects

Push the branch and open the pull request.

From Review, write the pull request’s title and description, then choose Push + open PR. Thalia works through the GitHub CLI.

GitHub remoteGitHub CLI (gh), signed in

A shell in every project.

Open the terminal under any chat (⌃`) to run commands in the project folder. For full-screen tools like editors and pagers, Open Terminal Here opens the folder in Terminal.

Notes that carry into every turn.

Keep notes for each project, and a personal memory that Muse shares with the CLI. Both go with each turn, and you can switch either off.

Your repository’s rules.

Turn on project rules in Settings, and Muse reads your repository’s rules file, such as THALIA.md or AGENTS.md, from the project root on every turn.

Off by default: turn on in Settings

Bring memory from other tools.

Import Markdown memory from another coding agent into your personal memory or a project’s notes.

Commands you can reuse.

Save a prompt as a slash command, for yourself or for a project. $ARGUMENTS fills in whatever you type after the name. Built-in commands cover plan mode, models, effort and checkpoints.

Give Muse the material.

Attach files to a message, or clip a web page’s text into your next request with /fetch.

Routines: saved prompts you run on demand.

Save a prompt against a project and run it when you need it, in a chat or headless in the background. Thalia can notify you when it finishes.

Runs on demand

Skills you can inspect and pin.

Create skills, or import them from a folder or from other agent tools on your Mac. Mark each revision trusted or not, and pin a revision to a project.

Connect the services you already use.

Guided presets for GitHub, Linear, Cloudflare, Sentry and GitLab walk you through setup.

Your own account and authorization for each service

Add any MCP server.

Add a custom connector over streamable HTTP, or as a local command, with OAuth sign-in where the server supports it.

Depends on the server

Connector keys stay in your Keychain.

Keys you enter for the guided GitHub and Linear connectors, and credentials for custom connectors, are stored in the macOS Keychain. Thalia won’t send a key over plain HTTP unless the server is on your Mac.

Know which connectors are live.

A connector that’s on but not signed in is skipped and marked, and Home counts it.

More than one account.

Add a second account for a service, each with its own named key.

A native Mac app.

Thalia is written in Swift and SwiftUI for macOS 26 and 27 on Apple Silicon.

Keyboard first.

The whole loop has menus and shortcuts, and Settings → Keyboard lists them all.

Light, dark, or follow the system.

Choose an appearance, or let Thalia follow macOS.

A layout you can shape.

Show or hide the sidebar, inspector and terminal, and reset the layout in one step.

A guide in the app.

A searchable guide explains each screen and term, and its keyboard section is generated from the app’s own commands.

Your work stays on your Mac.

Projects, chats, checkpoints and settings are stored on your Mac. Thalia sends Mabry Ventures no analytics, telemetry or usage data.

Muse works under your account.

When you chat, your messages and the files the agent reads go through the Muse Code CLI to Meta, under your Muse account and Meta’s terms. Sign in with your Meta account or a Muse API key; the key is handed to the CLI, which stores it.

Setup that checks its work.

If the Muse CLI is missing, setup installs it from Meta, checking the download first. Then it signs you in and confirms a live reply before you start. Thalia never updates Muse in the middle of a turn, and it asks before running Muse’s own update.

Diagnostics only when you ask.

A diagnostics bundle is made only on request. You see it redacted before saving, and it leaves your Mac only if you send it.