v0.4.1

Since v0.4.0

This is a patch release for calendar reasons, but contains a new feature that makes highly parallel workflow easier.

✨ Features

• Agents can now set statuses (with optional URLs for clicking)
  • It seems to pick decent emojis and URLs by default, but more in-depth customization is available via standard AGENTS.md guidance

• vim mode is now toggled with /vim, disabled by default for parity with Claude Code
• Code blocks now have line numbers and a copy to clipboard helper

🛠️ Fixes

• Fixed a bug where using "~" in the Project path would not resolve correctly and cause all workspace creates to fail
  • We both expand tildes by default now and only permit creating a project when the path exists and we can see it has a .git
• Fixed many bugs related to first usage when you don't have an API key set
  • User should now see clear instructions on how to resolve the issue vs. obscure errors
• Persistent chat errors (e.g. authentication, context_exceeded) are no longer auto-retried
  • Many general improvements to the retry and chat error behavior
• Interrupting a stream over SSH will now properly terminate in-progress bash tool calls and should complete nearly instantaneously
• Fixed a bug where editing a symlink would cause that symlink to resolve, most notably leading to issues when editing CLAUDE.md -> AGENTS.md type symlinks

⚠️ Known Issues

• Momentary UI freeze as tokenizer loads in on first UI launch - resolves within a few seconds
• Open Terminal doesn't work for SSH workspaces

v0.4.0

Since v0.3.0

✨ Features

• The headline feature of this release is SSH isolation for agents (docs)
• You can now run cmux as a stand-alone web app with: npm i -g @coder/cmux && cmux server
  • When paired with Tailscale or another secure tunnel this enables development from mobile devices such as phones and tablets

🛠️ Fixes

• Chat history is far more responsive on small viewports (e.g. when Review tab is open)
• An absolute ton of other bug fixes and performance improvements

⚠️ Known Issues

• Momentary UI freeze as tokenizer loads in on first UI launch - resolves within a few seconds

v0.3.0

Since v0.2.0

✨ Features

Integrated code-review system:

Maintained context display in thin viewports:

Real-time compaction streaming:

TODO lists:

Also:

• /compact now supports an optional -m <model> flag, e.g. /compact -m haiku to get a fast compaction
• /fork <name> to create a copy of the workspace, /new <name> to create a fresh one
• Syntax highlighting on all diffs
• Drag-and-drop image reading support for supported models
• Haiku 4.5 has first-class support via "haiku" abbreviation
• Rendering performance improvements

🛠️ Fixes

• Agents will no longer experience "amnesia" when resumed after an error
• Project Sidebar ordering persists through restarts
• Many compaction related bug-fixes

⚠️ Known Issues

• Startup can appear to freeze for up to 10 seconds, this goes away on second launch
• The experience is worth the freeze!

Telemetry

Note

This is the first version to ship with anonymized telemetry (details here)

v0.3.0-rc.2

Since v0.3.0-rc.1

✨ Features

• Context usage show up as thin vertical bar when viewport width is constrained
  • Context usage is now always visible when a chat is open
• /compact now supports an optional -m <model> flag, e.g. /compact -m haiku to get a fast compaction
• Haiku 4.5 has first-class support via "haiku" abbreviation
• Rendering performance improvements

🛠️ Fixes

• Project Sidebar ordering persists through restarts

⚠️ Known Issues

• Startup can appear to freeze for up to 10 seconds, this goes away on second launch
• The experience is worth the freeze!

v0.3.0-rc.1

Features

• Agent will manipulate a TODO list as it works to provide the user with better insight on future tasks
• Many rendering performance improvements

Fixes

• Mode switching has been improved on a chat protocol level, Agent will refuse to make edits in Plan Mode
• /compact UX is generally more reliable and robust to restarts

Known Issues

• Startup can appear to freeze for up to 10 seconds, this usually goes away on second startup

v0.2.1

Hotfix to improve splash screen behavior while app is loading

Known Issues

• Startup can appear to freeze for up to 10 seconds, this usually goes away on second startup

v0.2.0 — OSS

v0.2.0

This is the first open source release of cmux in a Preview state.

Here's an overview of major changes:

Features

• Workspaces are now sorted in Projects sidebar by recency
• Projects can be drag-and-dropped reordered in the sidebar
• Frontend shows live token streaming statistics
• Mode-specific sections in AGENTS.md (e.g. ## Mode: Plan)
• /compact -c "message" allows for automatic continuation of conversation post-compaction
• Workspaces now have an Unread status to make it easier to go where Human attention is needed

Performance

• Splash screen shows up immediately as a band-aid to slow app start
• Rendering has been optimized across the app, much less idle CPU draw
• Workspaces delete much more quickly

Genesis

Things are looking kind of stable here.

Notes omitted as there are no prior releases to compare with.