Jean lets a coordinator drive its own sessions. Synapse lets you wire any agent to any other. Jean (jean.build) is a free, Apache-2.0 desktop app that runs Claude, Codex, Cursor, OpenCode and others in parallel worktrees, with diff review, PRs and GitHub, Linear and Sentry integrations. It ships an MCP server so one Jean session can read another's messages and prompt it, plus an experimental coordinator mode. Synapse draws user-drawn, directional links that inject context on every prompt, works with agents started anywhere, and needs no coordinator. Jean is the more complete workspace.
At a glance
| Synapse | Jean | |
|---|---|---|
| What it is | Canvas and messaging layer for every agent on your machine, plus a desktop app in development | Tauri desktop app (plus headless Linux server) for agents in parallel worktrees |
| License | MIT, open source | Apache-2.0, open source |
| Price | Free | Free, no paid tiers |
| Account | None | None; Web Access uses a token |
| Live context links between running agents | Yes, user-drawn, directional, injected every prompt | No automatic per-link injection; manual Load Context |
| Agent to agent tools | Six MCP tools, CLI and skill, for any linked agents | Jean MCP server: read another session's messages, send it a prompt, check status |
| Coordinator agents | Not needed | Experimental, off by default |
| Sees agents it did not launch | Yes, by process scan | No, only sessions created in Jean |
| Gemini CLI, Amp, Copilot CLI | Yes | Not supported |
| Session forks | In development (Claude Code, Codex) | Not found in README or docs |
| Diff review, PRs, GitHub, Linear, Sentry | No | Yes |
| Remote server, web and phone access | No (multiplayer in development) | Yes |
Jean facts are from jean.build, its GitHub repo, source, developer docs, releases and issues, checked on 16 October 2026.
What Jean is
Jean is made by coolLabs, the team of Andras Bacsai, who founded Coolify. It is a Tauri desktop app with a Rust core, plus an optional headless jean-server for Linux that serves the full UI over the web, phones included. The desktop app can attach to several servers and show all their projects in one sidebar.
Each task gets a git worktree, and each worktree can hold several sessions. You mostly work in Jean's own chat UI, which drives the vendor CLIs underneath (Claude through stream-json and --resume), with plan, build and yolo modes, plan approval and session recaps. There are "magic" commands for investigating issues, code review, commit messages, PR descriptions and merge conflicts, a diff viewer with line comments, and integrations with GitHub, Linear, Sentry and CodeRabbit.
Supported backends are Claude, Codex, Cursor, OpenCode, Pi, Command Code, Grok, Kimi Code and Antigravity (beta). Jean reached v1.0.0 on 21 September 2026 and v1.0.11 on 14 October 2026. It has about 1,300 GitHub stars and is mostly written by one maintainer.
What Synapse is
Synapse puts every live coding agent on your machine on a canvas, grouped by git repo. Drag from one agent to another and the second one sees what the first is doing. On each prompt, a hook injects what the linked agent said since last time, capped at 8,000 characters per link. Linked agents can message each other through six MCP tools, a CLI and a skill.
It finds agents by scanning processes, so they do not have to be started by Synapse.
How agents talk to each other in Jean and in Synapse
Jean has the closest overlap with Synapse of any workspace we have compared, so here it is precisely.
Jean:
- Jean MCP, required since v1.0.0, is an MCP server Jean registers in each supported CLI. A session inside Jean can call
list_sessions,read_session_messages(up to 200 recent messages of another session),send_chat_message(a fire-and-forget prompt into another session, any backend),create_session,get_session_status,cancel_session_runand tools for diffs and PRs. So one Jean agent can read another's transcript and prompt it on demand. These are pulls the agent makes when it decides to, and depth and rate limits stop runaway loops. - Agents, experimental and off by default, are persistent backend agents, including a built-in coordinator called "Jean." They hand work to sessions, get results back automatically when a session finishes, can message each other, and have schedules and shared memory. Push, merge, delete and PR creation wait for your approval.
- Saved contexts let you summarize a session and attach it to another one by hand.
Synapse:
- Links are drawn by you and stay live. A link from A to B means B gets A's recent conversation injected on every prompt, without B having to ask. The canvas shows who reads whom.
- No coordinator is needed. Any two linked agents can message each other as peers.
- It works across tools. Synapse sees agents started in Jean, plain terminals, tmux or other workspaces, and supports Gemini CLI, Amp and Copilot CLI, which Jean does not host.
The fair summary: Jean's model is orchestration, where one agent drives others inside Jean through tools. Synapse's model is peer links, drawn by you, between any live agents on the machine. Jean's model is richer for automated delegation with approvals. Synapse's is simpler when you just want two agents to stay aware of each other.
Forks
Synapse's desktop app, in development, adds forks for side questions. Type /sfork <question> in Claude Code or Codex, or press ⇧⌘F, and Synapse forks the session natively into a card stacked on its parent, so the side question never enters the main context. The fork shows on the canvas as a dashed line. We did not find a conversation fork feature in Jean's README or docs.
Open source, accounts and privacy
Both are free and open source: Jean under Apache-2.0 and "free forever" with no paid tiers, Synapse under MIT. Neither needs an account. Jean does not mention telemetry on its site, and we have not verified either way. Jean talks to GitHub, Linear and Sentry when you use those integrations. Synapse makes no network calls and keeps links and messages in ~/.synapse.
Where Jean is ahead
- A complete workflow app. Worktree lifecycle, diff review with comments, PR and merge, investigation and review commands, issue automation, usage tracking. Synapse has none of this.
- Remote and web access. A headless server, a browser UI that works on phones, and one sidebar across several machines. Synapse's cross-machine multiplayer is in development, not shipped.
- Richer orchestration. A coordinator can create sessions, prompt them, poll status, read transcripts and get results back, with schedules, memory and approval gates.
- Platforms. macOS, plus Windows and Linux builds (lightly tested). Synapse is macOS first.
Using Synapse with Jean
- Keep Jean for worktrees, sessions, review and PRs.
- Install Synapse:
node install.mjs && npm start. - Check the canvas for the Claude and Codex agents Jean starts. Jean drives these CLIs in headless stream mode rather than an interactive terminal, so Synapse's per-prompt context injection may not apply on those turns. Test it on your setup.
- Use Synapse to link a Jean session with an agent Jean cannot host, such as Gemini CLI, Amp or Copilot CLI, or a Claude Code session in your IDE.
Who should pick which
- Pick Jean if you want one open-source app for worktrees, review, PRs and integrations, with remote access and a coordinator that can drive sessions.
- Pick Synapse if you want to link agents wherever they run, include Gemini CLI, Amp or Copilot CLI, or keep two agents aware of each other without writing an orchestration prompt.
- Run both if your agents live in Jean and outside it.
FAQ
Is Synapse a Jean alternative?
For linking agents across tools, yes. Synapse links any live agent on your machine with user-drawn links and peer messaging. For worktrees, review, PRs and integrations, no. Jean is a full workspace and Synapse is meant to work next to one.
Can Jean agents talk to each other?
Yes, inside Jean. Jean's MCP server lets one Jean session read another's recent messages and send it a prompt, and its experimental Agents feature adds a coordinator that delegates work and gets results back. It only covers sessions created in Jean.
Does Jean support Gemini CLI?
No. Gemini CLI support is an open request (issue #175), and Amp and Copilot CLI are not listed either. Synapse supports Gemini CLI, Amp and Copilot CLI.
Is Jean open source and free?
Yes. Jean is open source under Apache-2.0, and its site says it is "Open source and free forever" with no paid tiers. You bring your own CLI subscriptions. Synapse is free and MIT licensed.
What is the difference between Jean's coordinator and Synapse links?
Jean's coordinator is an agent that drives other Jean sessions through tools when it decides to. A Synapse link is drawn by you between any two live agents, and the target gets the source's recent conversation on every prompt without asking. No coordinator is involved.
Does Synapse see agents running inside Jean?
Synapse finds agents by process scan and Claude sessions through Claude Code's session registry, so Jean's agents should appear. Jean drives the CLIs headless, so Synapse's per-prompt context injection may not apply to those turns. Test on your setup.