What it does

The main features, with a short recording where one exists. Planned work is on the roadmap. Keys are given for Linux and Windows; the macOS equivalents are in Keybindings.

• Agents and sessions: sessions · hand the agent a file path · crop an image for the agent
• Navigation and previews: walk the project · Modules mode · PDF · pan and zoom · pin a file · edit a file
• The REPL: run code, see figures inline
• The window: searchable help
• Your machines: a remote backend, several frontends, sessions that outlive the connection

Agents and sessions

Claude Code and Codex sessions

Each agent session is one row in Sessions mode, on this machine or on any connected host. The row colour is the agent's work state, so you can see which session needs you without opening each one; the colours are listed in Work-state colours. Codex sessions have no REPL integration yet: only Claude Code sessions run Julia in the shared REPL.

Demo session rows changing colour as a script sets their work states: green working, red waiting for your answer, purple waiting on a job, blue done, gray idle. Each row's ready tag means its supervisor has a live agent process running.

Hand the agent a file path

In Files mode, c copies the selected file's path to the clipboard for pasting into the agent's prompt.

Pressing c in Files mode copies the selected file's path; Ctrl+V pastes it into the Claude Code session in the agent pane; asked what the script does, it answers in one sentence.

Crop an image for the agent

With the preview focused (Ctrl+Right), zoom into an image, then c crops the visible region and drops a ready-to-send line into the agent pane, naming the source file and the region, with the crop attached.

With the preview focused, pressing c on a zoomed figure puts the visible region into the agent's input, and the question is sent: asked which leg in it is the shortest, the agent reads the answer off the crop.

More on agents

• Agents run code in your REPL. Claude Code sessions run Julia in the session's persistent REPL, and each run appears in your REPL drawer. See How agents use the REPL.

• Agents can show you results. A session can open an image or file in your preview pane instead of describing it in text.

• Agents messaging each other. A built-in message relay (the comm relay) carries directed or broadcast messages between sessions, across machines; the same channel drives the row colours above. See Agents messaging each other.

Navigation and previews

Walk the project, see the file

In Files mode the cursor walks the tree and the preview pane follows it: markdown with typeset math, an HDF5 tree, a paged PDF, a figure.

The preview follows the cursor through notes with math, the agent's bar chart, an HDF5 file, a PDF and the route figure.

Modules mode

m switches the navigation tree to Modules mode — modules and their definitions — and the preview shows each definition's docstring and source as the cursor moves. Read-only, derived from JuliaSyntax.jl. See Modes.

Modules mode: the cursor moves through a module's definitions, with docstring and source in the preview.

PDF, paged

With the preview focused (Ctrl+Right), n pages a PDF forward and p back; each page rasterizes on the backend to fit the pane.

With the preview focused, n and p page through a PDF, then = zooms in to read it.

Pan and zoom images

With the preview focused (Ctrl+Right), = (or Shift+Up) zooms an image in and the arrow keys pan it. Same-size images in a directory share zoom and pan, so stepping through a run's plots keeps your framing.

With the preview focused, = zooms an image and the arrow keys pan; the next same-size image opens at the same zoom and pan.

Pin a file

In Files mode, p pins a file to keep it in the preview pane while you browse elsewhere; it still updates as it changes on disk.

Pressing p pins the preview to src/DemoProject.jl while the cursor moves on; pressing p again unpins it; the cursor returns to the pinned file, and the preview then follows the cursor.

Edit a file yourself

With the preview focused (Ctrl+Right), e opens the displayed file in the built-in editor in the preview pane; Ctrl+S saves and Escape closes it, asking first if there are unsaved edits. When the entry has a concept annotation (a note about it, written by you or the agent and kept under .concept/), e edits the annotation instead; see The concept layer.

There is no diff view of its own: you review the agent's edits in the preview pane, which follows a file as it changes on disk, in the REPL drawer, which shows every run the agent made, and with git in a shell session.

More on previews

• Add a file type in Julia. A FileType subtype, a matches method and a preview method; no Rust changes. See The dispatch ABI.

• Video and interactive documents open in the browser. Video shows a poster frame in the pane; o opens playback in your browser. Pluto notebooks, Quarto documents and HTML pages follow the same policy, served through the backend connection, local or remote, with no SSH setup.

The REPL

Run code, see figures inline

A persistent Julia REPL per session. Run a whole .jl file (r into a fresh REPL — this also clears what the agent built in Main — Shift+R into the current session) or type at the prompt. CairoMakie figures render inline in the drawer as images, not through a terminal graphics protocol. See The REPL.

Asked to run scripts/route.jl, the agent runs it in the shared Julia drawer; the output and the leg-distance bar chart land inline, then it answers.

The drawer's REPL and the agent's are the same Julia process and Main, one evaluation at a time; see How agents use the REPL.

• Interactive figures open in your browser. wglshow(fig) serves a live WGLMakie figure in your browser so you can pan, zoom and rotate in 3-D; the page and its WebSocket are served through the backend connection, local or remote, with no SSH setup.

The window

Searchable help

Ctrl+? overlays the focused pane's actions; press it again for the searchable Help drawer, Tab widens it to every pane, and typing narrows the list.

The Help drawer (Ctrl+? twice): Tab widens the scope to all panes, typing zoom filters the actions, Down steps through them.

• A local terminal. Ctrl+T opens the Terminal drawer, an OS shell on the frontend machine, typically used to SSH out to backend hosts.

• Fill the window. Alt+= maximizes the focused pane, Escape restores.

More on the window

• Watching the machines. The Monitor drawer (Ctrl+M) shows CPU, GPU and memory across your Linux hosts, for example while a training run is going.

• Keybindings. Named actions can be rebound in a keybindings file; anything you do not override keeps its default. See Keybindings for the lookup order and every key.

• Configuration. Layout presets for ultrawide, laptop and portrait screens, and a [gpu] setting for hybrid-graphics laptops; see Configuration files.

• More keys. Uploads and downloads, an image scalebar, text scaling and a printable cheat sheet of every key are on the Keybindings page.

Your machines

The setup is in Going remote.

• A remote backend. The backend daemon runs where your GPUs and data are; the window runs on your laptop or desktop and reaches it over SSH. The backend can also run locally, on Linux. Windows and macOS run as frontends to a Linux backend (macOS is experimental). See Platforms.

• Several frontends. A desktop and a laptop can attach to the same backend at once and see the same sessions, work-state colours and REPLs. See A second frontend.

• Sessions outlive the connection. Agent sessions run under their own supervisor, and their REPLs under the backend daemon, so a dropped connection stops nothing, and with a remote backend neither does closing the laptop lid or the window; the next launch reattaches. Closing the last window on the computer that runs the backend ends its sessions; Ctrl+Q can keep them. See Sessions and persistence.