Flock

Zellij meets herdr, plus more.

Flock is an agent-aware terminal workspace built on a fork of Zellij. It keeps Zellij's fast terminal multiplexing, layouts, plugins, sessions, web client, and collaboration model, then adds a control plane for coding agents and remote development environments.

What Flock adds

• Live agent status for Codex, Claude Code, OpenCode, Gemini, Kimi, Hermes, and other terminal agents: working, waiting, blocked, done, or offline.
• A unified sidebar for sessions, projects, cloud workspaces, panes, and attention badges, with direct focus and switching.
• A fast selector with fuzzy search, frecency ranking, project discovery, and switch-or-create behavior.
• Authoritative agent hooks for Codex, Claude Code, and OpenCode, with screen detection as the zero-config fallback.
• Remote providers for GitHub Codespaces, devcontainers, and Coder.
• Persistent Coder processes backed by a small remote PTY daemon, while the Flock multiplexer, layouts, configuration, and plugins remain on the laptop. Remote shells, jobs, and bounded output replay survive laptop and network disconnects.
• Coder workspace creation with optional dotfiles and typed connection state in the local sidebar.

Everything else is still Zellij. The executable is named flock, and the upstream Zellij documentation applies unless a Flock feature says otherwise.

Install

Download the archive, ZIP, or Windows installer for your platform from the latest Flock release. The current release is v26.10.1; v26.0.0 was the first Flock release.

To build from source:

git clone https://github.com/abeljim8am/flock.git
cd flock
cargo xtask build

For development builds and tests:

cargo xtask run
cargo xtask test

Enable Flock

The bundled flock-selector and flock-sidebar layouts work out of the box. Remote providers are opt-in:

plugin location="zellij:flock-selector" {
    root_dirs "~/src"
    codespaces_enabled "true"
    devcontainers_enabled "true"
    coder_enabled "true"
}

plugin location="zellij:flock-sidebar" {
    root_dirs "~/src"
    codespaces_enabled "true"
    devcontainers_enabled "true"
    coder_enabled "true"
}

Provider requirements:

• Codespaces: authenticated gh CLI.
• Devcontainers: devcontainer CLI and Docker.
• Coder: authenticated coder CLI. Persistent sessions currently require a Linux x86_64 workspace with tar, sha256sum, and curl, wget, or Python 3.

Debug builds pass their exact FLOCK_EXECUTABLE path into generated local Coder bridge panes, so cargo run -- ... tests the binary you just built instead of a different flock on PATH. Set FLOCK_EXECUTABLE=/absolute/path/to/flock to override it explicitly. Set FLOCK_BUILD_REMOTE_AGENT=1 when running cargo xtask run on a Linux x86_64 laptop to build and stream a static musl binary to the workspace as the remote agent. This opt-in build requires Zig, musl-gcc, or x86_64-linux-musl-gcc. On other platforms, point FLOCK_REMOTE_AGENT_BINARY at a cross-compiled Linux x86_64 Flock binary. Release builds continue installing the matching checksum-verified release.

Coder session lifecycle

Coder shells are intentionally owned by the workspace's remote PTY daemon, so the local host session can be suspended without terminating remote work:

• Detaching leaves the live host session and its remote shells running.
• Killing a session (including kill-all-sessions) synchronously saves its host layout, then disconnects locally. Reopening the same deterministic session name restores its tabs and reconnects to the same remote PTYs.
• Deleting a resumable session is final: Flock durably queues closure of every saved remote PTY before removing the host resurrection metadata. Interrupted closes are retried the next time Flock starts.
• Stopping or restarting the Coder workspace terminates the workspace daemon, so its remote shells are cleaned up immediately.

While a killed host session is intentionally suspended, its remote shells and jobs remain alive and may continue producing bounded replay output until the session is reopened, deleted, or the Coder workspace stops.

Agent hook integrations live in default-plugins/flock-sidebar/assets. They improve accuracy, but are optional because Flock can detect state from pane content and foreground processes. Each integration is universal: the same OpenCode plugin or Codex/Claude hook selects the local pipe, devcontainer file bridge, or Coder remote-agent transport from FLOCK_STATE_CHANNEL. Install the same integration versions in Coder workspaces through your dotfiles or agent configuration; Flock does not rewrite those configurations automatically.

Credits and license

Flock is built on Zellij and ports agent-state ideas and integrations from herdr into the terminal multiplexer itself. It is distributed under the MIT license.