OpenSessions is an open-source tool that pins a sidebar to the edge of your tmux screen so you can list and switch between all your running sessions. It tracks the live state of coding agents such as Amp, Claude Code, Codex, and OpenCode, and raises per-thread markers for done, error, and interrupted. Git branch names, working directories, and detected localhost ports are shown alongside them, so even when agents are running across several repositories at once, it is immediately clear which one is waiting on you. It is developed by Ataraxy Labs, built with Rust and ratatui, and released under the MIT license. It launched in March 2026.
Key Features
- Live agent state: Shows the running state of Amp, Claude Code, Codex, and OpenCode across sessions. You can see which agent is working and which has stopped without hopping between terminals
- Per-thread unseen markers: Records done, error, and interrupted as markers on each thread. Even if you leave a long task running unattended, it is harder to miss what happened when you come back
- Branch, working directory, and localhost port display: The list shows branch names, while the detail panel shows the working directory and thread names. Detected localhost ports are also displayed, so you can tell which session is running which dev server
- Keyboard-driven fast switching:
prefix o → sopens the sidebar,prefix o → tfocuses it, andprefix o → 1through9jump directly to a session. Inside the sidebar you can move with j/k, arrows, and Tab, and reorder, hide and restore, create, or kill sessions - Programmatic HTTP API: Scripts and agents can push arbitrary status, progress, and logs into the sidebar through endpoints such as
/set-status,/set-progress, and/log. A tone (neutral, info, success, warn, error) can be specified for color coding - Native Rust with no runtime dependencies: Written in Rust with ratatui, it installs through TPM (tmux Plugin Manager) by adding
set -g @plugin 'Ataraxy-Labs/opensessions'. It fetches a prebuilt binary on first load and can also be built from source with Cargo
Pricing
| Plan | Price | Highlights |
|---|---|---|
| Open source (MIT) | $0 | All features available free of charge. No paid tier or commercial license |
Pricing is current as of August 2026. Please check the official repository for the latest information.
Pros & Cons
✅ Pros
- Solves the “I can’t tell which one finished” problem of running several agents in parallel with a single sidebar
- Not tied to one agent — Amp, Claude Code, Codex, and OpenCode are all handled on the same screen
- Written in Rust with no runtime dependencies, so it is unlikely to slow down tmux startup
- The HTTP API lets you funnel your own scripts and CI notifications into the same sidebar
- Fully open source under MIT, with no cost and no account signup
⚠️ Cons
- Requires tmux (plus TPM and curl or wget). If you do not use a terminal multiplexer, getting started is a hurdle
- Only four agents are currently supported for state display; anything else has to call the HTTP API yourself
- The keybinding-centric model can be confusing at first if you are not used to the
prefixkey concept - As a relatively new project, specifications and keybindings may change with updates
- It is a TUI rather than a GUI dashboard, so it is not suited to charts or reviewing history
Comparison with Similar Services
| Criteria | OpenSessions | Claude Squad | sesh | Vibe Kanban |
|---|---|---|---|---|
| Main purpose | Agent state display and session switching | Managing parallel agent runs | Searching and switching tmux sessions | Agent task management |
| Interface | tmux sidebar (TUI) | Terminal UI | Terminal UI | Browser UI |
| Agent state visibility | Yes (4 agents + HTTP API) | Yes | No (focused on session management) | Yes |
| Requirements | tmux | tmux + git worktree | tmux | Browser |
| Price | Free (MIT) | Free (open source) | Free (open source) | Free (open source) |
Who Is It For
- Developers running agents like Claude Code or Codex across several repositories at once
- People who want to track agent progress without breaking a terminal-centric workflow
- Anyone who moves on to other work while waiting for agents to finish and checks them as they complete
- Those who want their own scripts and build status collected as notifications in the same place
- Heavy tmux users who would rather not add another browser dashboard
Summary
OpenSessions answers a very practical problem — the more agents you run in parallel, the harder it becomes to tell which one is waiting for you — with the minimal means of a tmux sidebar. It lines up the live state of Amp, Claude Code, Codex, and OpenCode, prevents oversights with per-thread markers, and lets you funnel your own notifications into the same place through its HTTP API. If you live in tmux and run multiple agents, the low cost of trying it — one line added through TPM — makes it well worth considering.