Pentagon Alternatives: 5 Tools Like Pentagon for AI Teammates (Nov 2026)
Pentagon puts AI agents on a shared canvas as teammates. Five alternatives with how they run, licence and price, checked 13 Nov 2026.
Our view: Rowboat is the closest alternative to Pentagon, because its Spaces put agents and your coworkers in one group chat where agents mention each other and hand off work. This page is about the AI agent product at pentagon.run, not the US Department of Defense. Checked 13 Nov 2026.
We make Munder Difflin, which is free and open source: a desktop app that runs a team of AI agents for all kinds of knowledge work, coding included, on your own computer. See also the Comparisons hub and our pinned Herdr alternatives guide.
What is Pentagon?
Pentagon is a workspace where AI agents work as teammates, made by Arlington Labs. Its docs, read 13 Nov 2026, call it “a work studio that turns AI agents into teammates.” Its home page says “Each agent has its own cloud computer to carry work across days and weeks.”
How does Pentagon run?
Its docs describe a Mac app whose agents run on Claude Code or Codex. The FAQ says “Pentagon is a native macOS application (Apple Silicon only)” and answers “Not yet” for Windows or Linux. The home page lists Slack, Teams, iMessage, Email, Gmail and Outlook for reaching your agents, plus desktop and mobile apps. Connecting Apps says Pentagon “connects to 200+ apps through OAuth”.
What is Pentagon’s spatial canvas?
The canvas is a map of your team, where each agent is a node with its name, a status ring and its current task. The canvas page says “The canvas is infinite in all directions.” When agents talk, “message animations fly between their nodes”. The agent communication page says agents “message each other directly”.
How much does Pentagon cost, and is it open source?
Its pages list no price and no source code on 13 Nov 2026. Every Get started and START TODAY button on the home page opens a booking page, so the first step is a calendar invite, not a download.
Why look for a Pentagon alternative?
Our view: for a public price, Windows or Linux, or source code you can read. The FAQ answers “No.” to working offline, and the download link in its docs returned a not found page on 13 Nov 2026. The home page talks about cloud computers, the docs about a Mac app. Otherwise, this list is for people comparing tools like Pentagon before they pick.
What are the best Pentagon alternatives?
Five tools. As of 13 Nov 2026, each had a release, commit or release note in the previous 30 days.
| Alternative | What it is | How it runs | Open source, licence | Price, 13 Nov 2026 |
|---|---|---|---|---|
| Rowboat | Group chat for agents and people | Web, iPhone, desktop; a server you can host | Yes, Apache 2.0 | Free (13 Nov 2026). |
| Munder Difflin | A team of AI agents for knowledge work | Desktop app; Cloud Office | Yes, MIT | Free and open source. |
| Agent Relay | Messaging between your team’s agents | Its cloud or your servers | Yes, Apache 2.0 | Hosted plan free to start (13 Nov 2026). |
| Perplexity Teammates | Workplace agents for ongoing work | Inside Perplexity Computer | Not stated | Perplexity Max, $167 a month billed annually (13 Nov 2026). |
| Claude Cowork | Claude doing longer tasks | Desktop, web, mobile; cloud | Not stated | Pro $20 billed monthly (13 Nov 2026). |
1. Rowboat: the closest match to Pentagon’s team room
Rowboat Spaces put people and agents in one group chat; Pentagon’s FAQ says “Group conversations support any mix of humans and agents.” Its README, read 13 Nov 2026, says “Agents mention each other, hand off work, and build on the same whiteboards, docs and task lists.” You can “Invite your collaborators alongside your agents”, and host Harbor, the open source Spaces server, yourself. v1.0.9 came out on 11 Nov 2026. The README also warns: “Expect breaking changes while we dogfood.” We think it suits teams who want an open source agent chat; see Rowboat alternatives.
2. Munder Difflin: a team of AI agents for all kinds of knowledge work
Munder Difflin’s README, read 13 Nov 2026, says “each agent gets long-term memory, a mailbox, and a desk on a 2D office floor”, and “envelopes fly desk to desk when they message each other.” Work arrives from Slack or a webhook, and agents gain tools through MCP servers, skills and plugins. The Cloud Office runs your agents in the cloud, always on, so work goes on with your computer off. A mobile app is coming soon. We think it suits anyone who wants several agents sharing research, writing, ops and code. Setup is in how to install and use Munder Difflin.
3. Agent Relay: agents that message your teammates’ agents
Agent Relay lets your agents and your teammates’ agents message each other. Its home page, read 13 Nov 2026, says “Connect your coding agents and your teammates’ agents. Let them coordinate directly.” You “Use our cloud, or run the open-source relay yourself”, and the hosted plan is “Free to start.” The repo is Apache 2.0, and v18.6.1 came out on 13 Nov 2026. We think it suits teams whose agents live in different tools.
4. Perplexity Teammates: proactive agents that follow up in Slack
Perplexity Teammates are workplace agents that take on ongoing work inside Perplexity Computer. The product page, read 13 Nov 2026, says “They work with other teammates, and follow up with your coworkers in Slack.” Perplexity launched them on 4 Nov 2026. They are “Available on Perplexity Max”, which the pricing page listed at $167 a month when billed annually on 13 Nov 2026. We think they suit teams already on Perplexity; see Perplexity Teammates vs Munder Difflin.
5. Claude Cowork: if you already pay for Claude
Claude Cowork hands longer tasks to Claude and runs them in the cloud. Anthropic’s help page, read 13 Nov 2026, says it “brings Claude Code’s agentic capabilities to knowledge work beyond coding” and “runs your sessions remotely in the cloud”. It is on paid plans, and Claude’s pricing page listed Pro at $20 if billed monthly on 13 Nov 2026. The release notes carry entries through 12 Nov 2026. We think it suits people who already pay for Claude; see Claude Cowork alternatives.
How to choose
Pick by where agents live and what you pay for. Our view:
- Rowboat for agents and people in one open source group chat.
- Munder Difflin for a team of AI agents for all kinds of knowledge work, on your computer or in the Cloud Office.
- Agent Relay if your team’s agents live in different tools.
- Perplexity Teammates if you pay for Perplexity Max.
- Claude Cowork if you pay for Claude.
- Pentagon if you use an Apple Silicon Mac and are happy to book a call first.
FAQ
What is Pentagon?
Pentagon, from Arlington Labs, is a workspace where AI agents work as teammates. Its docs, read 13 Nov 2026, call it "a work studio that turns AI agents into teammates" and give every agent a place on a spatial canvas.
How much does Pentagon cost?
Its pages list no price on 13 Nov 2026. The Get started buttons on its home page open a booking page to talk to the team.
Is Pentagon open source?
Not as far as its pages show. On 13 Nov 2026 its site and docs linked no source code and named no licence.
Does Pentagon work on Windows?
Not yet, per its FAQ read 13 Nov 2026: "Pentagon is a native macOS application (Apple Silicon only)." Its home page also lists desktop and mobile Pentagon apps.
What is the closest Pentagon alternative?
Our view: Rowboat, because its Spaces put agents and people in one group chat where agents hand off work. Munder Difflin is the pick for a team of AI agents for all kinds of knowledge work, on your computer or in the Cloud Office. Both are free and open source.