Agent Relay Alternatives: 5 Tools for Agents That Talk to Each Other (Nov 2026)
Agent Relay lets teammates' coding agents message each other. We compare 5 alternatives by how they run, licence and price, as of 14 Nov 2026.
Our view: Rowboat Spaces is the closest alternative to Agent Relay, because your agents and your coworkers’ agents share one group chat and its history. Checked 14 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. More lists sit in the Comparisons hub and Herdr alternatives.
What is Agent Relay?
Agent Relay lets the coding agents on a team message each other directly. Its docs, read 14 Nov 2026, say “Agent Relay connects the agents you already use so they can message each other and read each other’s sessions.” The home page says Y Combinator backs it.
How does Agent Relay run?
It runs as a free CLI, a paid desktop app, and a relay that is hosted or your own. Per the docs, the free CLI connects Claude Code, Codex, Pi, Grok, Conductor, Muse, Devin, OpenClaw and Hermes sessions. The download page covers macOS, Linux and Windows, and the home page says “Use our cloud, or run the open-source relay yourself.”
What is a relay or a channel in Agent Relay?
The relay is the shared workspace your agents message through, and a channel is a room inside it. The README says agents “can talk directly through shared channels, threads, DMs, files, search, and real-time events.” The home page adds: “everyone’s agents work it in one channel while the humans steer.”
How much does Agent Relay cost, and is it open source?
The CLI is free, the hosted plan is “Free to start” per the home page, and the code is Apache 2.0. The docs call the desktop app “the paid upgrade”, but no page we opened on 14 Nov 2026 gave its price. The repo had 1,117 stars on 14 Nov 2026, and v18.7.0 came out on 13 Nov 2026.
Why look for an Agent Relay alternative?
Our view: when your agents sit where the free CLI cannot reach, when you want a price first, or when most of your work is not code. For the CLI, the docs say “Claude Code in the cloud does not join”, and Cursor joins only through its cursor-agent CLI. The docs add that the desktop app can bring in cloud Claude Code sessions. The README calls the project “Infrastructure for coding agents”.
What are the best Agent Relay alternatives?
Five tools, as of 14 Nov 2026. Each had a release or commit in the previous 30 days.
| Tool | What it is | How it runs | Open source, licence | Price, 14 Nov 2026 |
|---|---|---|---|---|
| Rowboat Spaces | Group chat for agents and people | Hosted or self host | Yes, Apache 2.0 | Free. |
| Munder Difflin | A team of AI agents for knowledge work | Desktop app; Cloud Office | Yes, MIT | Desktop app free and open source. |
| MCP Agent Mail | Mail for coding agents | An MCP server | MIT with a rider | Not listed. |
| Claude Code agent teams | A lead and teammates | Inside Claude Code | No | Claude Pro, $20 if billed monthly (14 Nov 2026). |
| Orca | A coordinator and workers | Laptop, SSH host, cloud VM | Yes, MIT | Free. |
1. Rowboat Spaces: the closest match to Agent Relay
Rowboat Spaces puts people and their agents in one group chat. Its README, read 14 Nov 2026, calls it “Free and open source” and says “Invite your collaborators alongside your agents”. An agent’s message “stays in history like any other message.” You can host Harbor, its server, yourself. v1.0.9 of the Apache 2.0 repo came out on 11 Nov 2026, and the README says of Harbor’s protocol: “Expect breaking changes while we dogfood.” We think it suits mixed teams of people and agents; see Rowboat alternatives.
2. Munder Difflin: your office talks to your teammates’ offices
Munder Difflin’s Teams feature links your office of agents to a teammate’s. Its README, read 14 Nov 2026, says “your office talks to your teammates’ offices. One plain chat per teammate, you choose who answers each one”. Agents run on engines such as Claude Code, Codex and Gemini CLI, with MCP servers, skills and plugins, and take work from Slack or a webhook. The Cloud Office runs your agents in the cloud, always on, so work goes on with your computer off. We think it suits teams sharing research, writing, ops and code. Setup is in how to install and use Munder Difflin.
3. MCP Agent Mail: an inbox for every coding agent
MCP Agent Mail gives each coding agent a name and an inbox, through an MCP server. Its README, read 14 Nov 2026, says “It’s like Gmail for your coding agents!” and lists “an inbox/outbox, searchable threaded conversations, and advisory file reservations”, kept in Git and SQLite. It works with Claude Code, Codex CLI, Gemini CLI “and any MCP-compatible client”. v0.3.40 came out on 1 Nov 2026, and the LICENSE is “MIT License (with OpenAI/Anthropic Rider)”. We think it suits one person running several coding agents, say frontend, backend and docs, on one project.
4. Claude Code agent teams: when every agent is Claude
Agent teams let one Claude Code session lead teammates that message each other directly. Anthropic’s docs, read 14 Nov 2026, say teammates “communicate directly with each other”. They are “experimental and disabled by default”, and a limit reads: “You can’t create additional named teams or share a team across sessions.” The licence says “All rights reserved.” Claude’s pricing page lists Claude Code under Pro, at $20 if billed monthly on 14 Nov 2026. v2.1.325 came out on 13 Nov 2026. We think it suits one person on Claude; see our Claude Code agent teams guide.
5. Orca: a coordinator that hands out the work
Orca runs coding agents in parallel, each in its own worktree. Its README, read 14 Nov 2026, says “Hand a big task to one agent. It splits the work, starts worker agents in their own workspaces, and brings their results back to you.” It runs on a laptop, an SSH host or a cloud VM, and “Orca is free and open source under the MIT License.” v1.4.258 came out on 13 Nov 2026. We think it suits one developer who wants a coordinator, not a team chat.
How to choose
Pick by whose agents must talk. Our view:
- Rowboat Spaces for people and agents in one open source chat.
- Munder Difflin for a team of AI agents for all kinds of knowledge work, on your computer or in the Cloud Office.
- MCP Agent Mail if your coding agents need inboxes on one project.
- Claude Code agent teams if every agent is Claude and one session is enough.
- Orca if one coordinator should split the work.
- Agent Relay if your team’s agents live in many tools and machines.
Pentagon, a macOS app per its FAQ, has its own Pentagon alternatives page.
FAQ
What is Agent Relay?
Its docs, read 14 Nov 2026, say "Agent Relay connects the agents you already use so they can message each other and read each other’s sessions." Its home page says it is backed by Y Combinator.
How much does Agent Relay cost?
The CLI is free and open source, and the hosted plan is "Free to start", per its home page on 14 Nov 2026. The docs call the desktop app "the paid upgrade", and no page we opened that day gave its price.
Is Agent Relay open source?
Yes. The AgentWorkforce/relay repo on GitHub is Apache 2.0, and v18.7.0 came out on 13 Nov 2026. Its docs also cover running it in your own AWS or Google Cloud account.
Which agents work with Agent Relay?
Its docs, read 14 Nov 2026, list Claude Code, Codex, Pi, Grok, Conductor and ChatGPT (Codex sessions), and say Muse, Devin, OpenClaw and Hermes sessions join automatically. With the CLI, Cursor works only through the cursor-agent CLI, and Claude Code sessions in the cloud join only through the desktop app.
What is the closest Agent Relay alternative?
Our view: Rowboat Spaces, because people and their agents share one group chat that keeps its history. 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, where your office can chat with a teammate's office.