The terminal workspace for AI coding agents.

Panes, tabs and workspaces for Claude Code, Codex and any other CLI agent — with a command line the agents themselves can drive to split, prompt, wait and coordinate.

Install Releases Source

Windows 10/11 and Linux, x86_64. Open source under the Apache 2.0 license.

 ◫  Workspaces        │ starcil  api   +
 1 starcil        ●   │╭ claude ────────────────────────────╮
   api                ││ ✴ Read src/composer.rs             │
                      ││ ✴ Edit composer.rs                 │
                      ││                                    │
                      ││ ❯ run the e2e, fix what fails      │
 new           menu   ││                                    │
──────────────────────│╰────────────────────────────────────╯
        agents        │╭ codex ─────────────────────────────╮
 ⠹ reviewer·claude    ││ • Working (2m 14s · esc to stop)   │
 ✓ worker·codex       ││                                    │
                      │╰────────────────────────────────────╯

See it in action

One Claude Code pane bootstraps a fleet: it reads the Starcil skill, splits the window into a 2×2 grid, starts a second Claude and two Codex agents in the other panes and waits for them with starcil agent wait — the sidebar lists all four with their state.

Install

One command downloads the latest release, verifies its SHA-256 checksum, puts starcil on your PATH and leaves your config alone. Run it again to upgrade.

Windows PowerShell

PS> irm https://starcil.xtarify.app/install.ps1 | iex

Prefer a file? Download the zip, unpack starcil.exe anywhere on your PATH.

starcil-x86_64-pc-windows-gnu.zip latest
SHA256SUMS

Linux & macOS x86_64 & arm64

$ curl -fsSL https://starcil.xtarify.app/install.sh | sh

Installs into ~/.local/bin. The server listens on a Unix socket; bash and zsh panes get the same composer, agent detection and live cwd as on Windows. macOS panes open login shells, like Terminal and iTerm do, so Homebrew and your agents are on PATH.

starcil-x86_64-unknown-linux-gnu latest
starcil-aarch64-unknown-linux-gnu latest
starcil-x86_64-apple-darwin latest
starcil-aarch64-apple-darwin latest

Then open a terminal and run starcil. A named session (starcil --session work) gets its own server and workspace tree. Starcil checks GitHub for new releases on start and asks before installing one.

Built for the way agents work

Starcil is a multiplexer first: a headless server owns the terminals, the TUI is a client, and every action is available from a CLI and a socket API.

◫ Workspaces, tabs, panes

Split, resize, zoom, drag tabs to reorder, name everything. Sessions survive a closed terminal and restore on the next launch, in the directory each pane was in.

✴ Agent detection

Claude Code, Codex, Gemini, OpenCode, Copilot and 16 more CLIs are recognized when they start in a pane. The sidebar shows who is working, idle or blocked on a question.

❯ One place to type

Each shell pane has a composer with Tab completion, history and shell-style editing keys. Type below, see the output above; a dock launches your agents in one click.

$ A CLI for agents

starcil pane split, starcil agent start, starcil agent prompt --wait: an agent inside a pane can spawn peers, brief them and collect results.

⟳ Hooks and resume

Claude Code and Codex hooks report status without screen scraping. Sessions can be resumed natively. Worktrees open as their own workspace.

⌘ Mouse, themes, keys

Full mouse support (also under Warp), 12 themes plus overrides, a configurable keymap, sounds for state changes, and an in-app settings editor.

Let the agent run the fleet

Starcil ships its own skill: starcil --skill prints the instructions an agent needs to split panes, start peers, hand them briefs and wait for results. Install it once for Claude Code with the skills CLI, or paste the output into any agent.

# from inside a Starcil pane
starcil pane split --current --direction right --no-focus
starcil agent start reviewer --kind codex --pane w1:p2
starcil agent prompt reviewer "review the diff in this repo, write findings to REVIEW.txt" --wait
starcil pane read w1:p2 --source recent --lines 40

# teach Claude Code the skill, once
npx skills add daybigo/starcil --skill starcil -g

The composer

The input at the bottom of every shell pane is a real line editor. Nothing reaches the shell until Enter, so what you see is exactly what runs.

`Tab` / `Shift`+`Tab`	complete paths against the pane's live directory, or commands from PATH; repeat to cycle
`↑` `↓`	walk the history, filtered by what you typed; seeded from your shell's own history
`Ctrl`+`R`	incremental history search
`Ctrl`+`←` `Ctrl`+`→` `Ctrl`+`W` `Ctrl`+`U` `Ctrl`+`K`	move and delete by word or to the ends of the line
`Ctrl`+`V`	paste into the draft; a multi-line paste runs line by line
`Alt`+`1`…`9`	launch a dock agent in the current pane
`Ctrl`+`C` `Ctrl`+`L` `Ctrl`+`D`	reach the shell when there is nothing drafted

Made by Xtarify

Starcil was born inside Xtarify, the tool that builds your business website by talking with AI: no templates, no designers — describe what you do and your site is ready to publish in under a minute. Starcil is the ground the agents behind those sites will work on, which is why it is open for anyone to use with their own agents.