Athas now runs on a new editor engine built for large files. Every editor feature moved to CodeMirror 6, including LSP navigation, refactoring, diagnostics, hover, completion, vim, find, the minimap and sticky scroll. Typing in a 200,000-line file costs about the same as in a small one, and the editor no longer re-renders the rest of the window on each keystroke.
Files open noticeably faster. Clicking a file in the tree paints its text sooner, because indexing, focus, tree updates and other work that can wait now happen after the first frame. Markdown previews update only the blocks you edit, and find, git blame and semantic highlighting no longer rescan the whole file while you type.
You can browse the web in a tab. Pages open in browser tabs inside the workbench, keep their place when you switch tabs, and stay visible as a snapshot when menus or dialogs open on top of them.
The agent chat is redesigned, and the built-in agent can do more. Every agent runs in the same chat, with a context meter, steps and cost under answers, keyboard answers to permission prompts and a timeline of past sessions in the sidebar. The built-in agent can use your MCP servers, follows project rules, reviews its changes in a tab and inline in the editor, and keeps checkpoints so you can restore files from before a turn.
Inline edit and Tab autocomplete are easier to use. Inline edit previews its change as a diff and now shows the instruction, model and actions in two clear rows with their shortcuts. You can start it from the selection toolbar, and Tab autocomplete shows its model and status with real error messages.
Quick open is now a search hub. Besides files and symbols, it finds Git branches and commits, GitHub pull requests and issues, open tabs and agent sessions. Code outside the editor, such as diffs, search results and the SQL bar, is highlighted with the same grammars as the editor.
Source control and GitHub have a new stream layout. Changes, history, pull requests, issues and actions read as one stream, and two pull requests opened side by side no longer overwrite each other.
Settings opens in a large dialog with a compact layout. Settings are grouped into cards with one control style, and a compact UI density can be turned on and is restored at startup. Commands from the palette, menus and shortcuts now share one list, so every action can have a keyboard shortcut.
Your work is safer. Athas refuses to overwrite files that changed on disk, asks about unsaved changes once when closing tabs or windows, asks before trusting an unknown SSH host key, respects AI ignore files and keeps prompts and file paths out of crash reports.
Terminals and git handle heavy output better. Terminal output is sent in larger batches, so commands that print a lot use far less work, and terminal tabs can now be cleared and exported from their menu. Git blame stays ready after you commit or switch branches.
Athas uses the system webview on every platform. The bundled browser engine is gone, which makes the app smaller, and window commands such as full screen, minimize and maximize work from the command palette.