Coterm

Coterm is a native macOS workspace where two developers can pair in a shared terminal, browser, and coding-agent session. A live room lets participants follow the terminal, see who is present, and share previews. Supported agents include Claude Code, Codex, OpenCode, Gemini CLI, Aider, Amp, Cursor Agent, and other CLI agents. Its Ghostty-based terminal has vertical tabs, a notification panel, and a socket-based control API; programmatic control is also available through a CLI and Unix socket. Coterm's collaboration relay, control plane, presence, and approval flow run in the user's own Cloudflare account, and the Mac app works locally without a Coterm-hosted account service. The app is free under GPL-3.0-or-later and can be installed from a DMG or Homebrew. It requires macOS 14.0 or later on Apple Silicon or Intel Macs. An iOS companion app is available in beta for attaching to a Mac's terminals. After relaunch, Coterm restores layout and metadata but does not checkpoint arbitrary live process state; unsupported apps reopen as normal terminals. Its privacy policy says it may collect crash diagnostics, OS and app versions, and anonymous usage patterns.

Coterm is a free macOS pairing workspace with shared terminal sessions and a self-hosted collaboration option. Keep its macOS requirement and session-restore limit in mind, and note that the iOS companion remains in beta.

Coterm suits developers who want to pair in real time in a shared terminal and coding-agent workflow on macOS. It may also fit users who want collaboration infrastructure hosted in their own Cloudflare account.

Coterm is a macOS workspace for developers who want to pair inside a shared terminal and coding-agent session. Its free, self-hosted collaboration model will appeal to pairs comfortable running their own backend; teams that need Windows or Linux desktop support should look elsewhere.

The draw is a focused pairing workflow that keeps both developers in the same working context. Its main trade-offs are the macOS requirement and the inability to preserve live process state across relaunches.

Overview

Two developers can join a live room, follow the terminal, see who is present and share previews. Coterm is built for collaborative terminal work, not screen sharing: it has no screen-sharing feature. That distinction matters for pairs who want to work in a shared CLI session, but makes it a poor fit when the collaboration depends on seeing and controlling another person’s entire desktop.

The Mac app runs locally, and pair programming uses a collaboration relay, control plane, presence and approval flow hosted in the user’s Cloudflare account rather than a Coterm-hosted account service. This gives technically capable teams control of the collaboration backend, but means the self-hosting step is part of the product’s operating model.

Key features

Shared terminal and agent work

Coterm’s shared workflow supports Claude Code, Codex, OpenCode, Gemini CLI, Aider, Amp, Cursor Agent and other CLI agents. That makes it a natural fit for pairs who want to work with an agent in the same session. The app also includes configurable integration hooks for Claude Code, Amp, Cursor, Gemini and Kiro CLI, giving users a way to connect those tools to their workflow.

Terminal controls and recovery

The Ghostty-based terminal offers vertical tabs, a notification panel and a socket-based control API. A CLI and Unix socket expose commands for programmatic control, which should suit users who want to automate or integrate terminal operations. Coterm restores layout and metadata after relaunch, but not arbitrary live process state; unsupported apps reopen as ordinary terminals. Users relying on long-running processes should not treat session restore as a checkpoint.

Privacy and data flows

The app runs locally, and user code, files and content are not sent to Coterm’s servers during normal use. Its privacy policy also says it may collect crash diagnostics, operating-system and app versions, and anonymous usage patterns, and that it does not sell personal information for marketing. The iOS terminal stream travels directly between phone and Mac over the user’s network, while forwarded notification text can pass through Coterm servers and Apple’s push service. That distinction is worth considering for users with stricter notification privacy requirements.

Pricing

Coterm is free to use: the Coterm plan costs nothing and includes the macOS app under GPL-3.0-or-later, with an optional self-hosted collaboration backend. There is no free trial because the product is already free. The plan suits individual Mac users and pairs willing to self-host; there is no paid tier or hosted collaboration plan to choose instead.

Platforms

The desktop app runs on macOS 14.0 or later, on Apple Silicon and Intel Macs, and installs from a DMG or Homebrew. The iOS companion is in beta and can attach to a Mac’s terminals, so it is an additional mobile option rather than a substitute for the Mac app. Coterm also offers an API and a self-hosted option, but the native desktop requirement rules it out for teams needing a Windows or Linux Mac-app equivalent.

Who it's for

Coterm is best for two developers already working on Macs who want to pair in a terminal, collaborate alongside CLI agents and manage their own collaboration infrastructure. Its free price and local-first operation make it appealing to cost-conscious technical pairs. It is less suitable for teams that need screen sharing, cross-platform desktop clients or reliable restoration of running processes.

Pros and cons

• Pros: Free to use under GPL-3.0-or-later, with an optional self-hosted pairing backend; useful agent coverage for pairs working in CLI tools; CLI and Unix socket control support programmatic workflows.
• Cons: The desktop app requires macOS 14.0 or later; teams must run the collaboration backend themselves; relaunch restores layout and metadata, not live process state; there is no screen sharing.

Alternatives

• Pair Programming Software is a useful place to compare more tools in the category.
• Teamtype is another free option with Android, Windows and Linux support as well as macOS, making it a better starting point for mixed-platform teams.
• Visual Studio is a better fit for Windows users seeking a full IDE, with a free Community plan for students, open-source work and individual developers.
• Zed suits developers looking for a cross-platform code editor with a free Personal plan that includes 2,000 accepted edit predictions and external-agent or API-key support.
• CodeInterview is a stronger match for structured remote interviews: its free plan allows two interviews per month with unlimited users and all languages and frameworks.
• Drovio is worth considering when screen sharing and remote control are priorities; its free Basic plan allows up to two participants, with remote control limited to 30 minutes per day.
• Duckly offers a free plan for occasional sessions with two simultaneous participants and no video calls, making it an alternative for pairs seeking a browser or extension workflow.
• Hopp offers a free self-hosted option for teams that want to run a collaboration tool on their own infrastructure.
• Pop is another option for teams comparing meeting-focused tools.

Verdict

Choose Coterm if you and a partner work on Macs and want a free shared terminal workflow that accommodates CLI agents, with the control of self-hosting. Look elsewhere if you need screen sharing, broader desktop-platform support or relaunches that preserve running process state.