Superlogical Rex: Mitchell Hashimoto's Terminal Multiplexer
TL;DR
Superlogical Rex, the terminal multiplexer from Mitchell Hashimoto's new company, opened public testing on macOS in October 2026. What it is, cost, and access.
Last updated: October 9, 2026
Superlogical is Mitchell Hashimoto's new company, announced July 29, 2026, and Rex is its terminal multiplexer. Rex opened public testing on October 5, 2026: invites go out in waves to the Superlogical mailing list, only the macOS app is in the test so far, and Superlogical says Rex "is and will always be free", needs no account, and can be fully self-hosted. It is the first step toward a "multiplexer for all work" that unifies interactive, automatic, and production work.
Updated October 9, 2026: this post originally covered the July announcement, when nothing had shipped. Superlogical has since named the multiplexer Rex, started public testing on macOS, and published Rex docs. The new section below covers what is available now.
The launch: a terminal multiplexer company from the HashiCorp founder#
Mitchell Hashimoto has started a new company. That sentence alone was enough to send Superlogical to the top of Hacker News on July 29, 2026 (the thread has since reached 796 points and 458 comments). The HashiCorp co-founder and creator of Vagrant, Terraform, Vault, and (more recently) Ghostty is returning to building a developer tool - this time with a founding team that reads like a who's-who of infrastructure and design leadership.
The company describes its mission as building "the multiplexer for all work." They are starting with a terminal multiplexer, but the stated vision goes much further: a durable session layer that spans local development, remote access, coding agents, background jobs, production applications, live debugging, shared terminals, incident response, and multiplayer work.
The announcement came through a personal blog post by Hashimoto and the Superlogical website, both published simultaneously. Hashimoto made a point of noting he wrote the announcement himself: "No AI! Hand-written, real, and authentic."
The team: a HashiCorp-Vercel-Heroku lineage#
Superlogical's founding team is unusually deep for a seed-stage developer tools company:
- Mitchell Hashimoto - Creator of Ghostty. Co-founded HashiCorp and created Vagrant, Terraform, Vault. Served as CEO and CTO through HashiCorp's IPO.
- Jack Pearkes - First HashiCorp employee, VP of Engineering and VP of R&D.
- Alasdair Monk - Head of Experience at Poolside, VP of Design at Vercel, senior design leader at HashiCorp and Heroku. Two decades of developer-facing design.
- Hector Simpson - Designed apps, services, and agentic experiences at Poolside, Heroku, HashiCorp, and Vercel.
The investors are equally notable: Notable Capital, Amplify Partners, and angel investors including Aaron Levie (Box CEO), Patrick Collison (Stripe CEO), Tobias Lutke (Shopify CEO), Guillermo Rauch (Vercel CEO), and Armon Dadgar (HashiCorp co-founder). The site lists 14 angels in all, including Dax Raad, Mario Zechner, Steve Ruiz, and Paul Copplestone.
What they are actually building#
The concrete first product is a terminal multiplexer, now named Rex - think tmux or zellij, but modern. Sessions will be accessible through web and native macOS/iOS applications. Sharing a live session with other people is built in from the start. Hashimoto says they are addressing the common papercuts of existing multiplexers: "making scrollback, selection, and scrolling all work natively."
The multiplexer is built on libghostty, the MIT-licensed terminal library Hashimoto's team extracted from Ghostty. He was explicit that Ghostty remains an independent non-profit project whose "mission, governance, license, technical goals, and roadmap do not change." Superlogical consumes the same public building block available to everyone else and will continue upstreaming shared work.
Beyond the terminal multiplexer, the vision is deliberately larger. Superlogical's website describes a future where interactive work (a person at a keyboard), automatic work (CI, background jobs), and production work (deployed systems) all share one underlying session layer. The three-part plan is: (1) build an incredible multiplexer, (2) make everything in it composable, (3) make it safe and operable in production.
Rex: what is in public testing now#
Superlogical's October 5 update put a name and a date on the multiplexer. The company pitches Rex as "a drop-in replacement for whichever terminal you use today", with persistent sessions, remote connections, and program activity status as the headline capabilities. The facts that matter if you want in:
| Question | Answer as of October 9, 2026 |
|---|---|
| How do I get it? | Join the mailing list on superlogical.com. Invites go out in waves, and Superlogical intends to work through the whole list in under a month |
| Which platforms? | macOS only for now. The Mac app runs its own Rex server and can connect to Rex servers on your other Macs. Linux and Windows servers and iOS, Linux and Windows clients exist but are not part of the test yet |
| What does it cost? | Free. No account, no data sharing, and self-hostable servers. The commercialization plan has not been announced, but Superlogical says the Rex clients and servers will not be directly monetized |
| How mature is it? | About 50 people ran it in a private test, and the team says it has used Rex for real work daily for months |
| Where are the docs? | Rex docs are public, though the download needs a tester login |
The detail most relevant to anyone running coding agents is in the docs, not the announcement. Rex defines a Program Status Protocol, an OSC 7501 escape sequence that "lets a program tell the terminal what it is doing: idle, working, waiting on the user, finished, or failed, and why." The spec names coding agents alongside builds and deployments as the long-running work it targets. Compare that with Herdr, which infers whether an agent is working or blocked by reading the screen. Rex asks the program to say so. If agent harnesses adopt the sequence, "is my agent waiting on me?" stops being a guess, but that depends on adoption that has not happened yet.
The other open question is commercial. Rex is free and self-hostable by design, which leaves the paid layer to the second and third parts of the plan: composability and production operations. Superlogical says it will talk about that before the stable release.
What HN is saying#
The HN discussion was among the most-commented stories on the front page that day and reflects the range of reactions you would expect when a famous builder announces a new company with substantial funding.
Excitement about the team. The most-upvoted sentiment was trust in the founder. One top commenter wrote: "This is an incredible idea. I would usually be skeptical that such an engineering-focused tool would 'make it,' but Mitchell Hashimoto is one of the very few people I think can pull it off." Another added: "This guy is the inventor of quite a bit of architecture software supporting modern systems. I think it will be fine."
The "why not k8s?" question. Several commenters asked how a "durable session around work" differs from what Kubernetes already does. The replies pointed out that k8s handles orchestration and scheduling but does not provide the human-facing session layer for interactive and agent-driven work. One commenter synthesized it well: "K8s is just the last 100 meters."
Funding questions. Multiple commenters questioned why a billionaire would take venture funding. Others pointed out the practical reasons: accountability, recruiting, and strategic advice. One commenter noted: "Had it been hyper growth startup you would be looking at a16z or other bigger names." The investor list reads more like an advisory board of domain experts.
Skepticism about scope. Some commenters wondered whether a terminal multiplexer is the right starting point for such an ambitious vision. Others pointed to existing tools like tmux and zellij, asking what new ground Superlogical could cover. The counterargument: a terminal multiplexer is the narrow foundation for a broad vision, and the team has the track record to make it work.
The "ssh superlogical.jobs" moment. One commenter discovered the hiring page is accessible via ssh superlogical.jobs - a terminal-appropriate touch that generated a thread of approval.
Why it matters#
A terminal multiplexer may sound like a narrow starting point for a funded company, but it sits at an increasingly important intersection. As terminal agents become the portable runtime surface for AI development, the multiplexer layer is where human sessions, agent sessions, CI jobs, and production debugging converge. A modern multiplexer that handles scrollback, history, sharing, and reconnection natively removes friction that every developer using terminal-based coding agents hits daily.
Hashimoto's work on Ghostty proved that there is appetite for rethinking foundational developer tools when they are fast, well-crafted, and open. Superlogical is extending that same thesis to the session layer - the connective tissue between the tools, environments, and agents a developer touches in a day.
The timing is telling. A year ago, a "terminal multiplexer company" would have raised eyebrows even with this team. In mid-2026, with AI agents running in terminals, developers managing multi-session workflows across local and remote machines, and the line between interactive and automated work blurring daily, the problem feels more real than it did when tmux was written in 2007.
FAQ#
What is Superlogical?#
Superlogical is a company founded by Mitchell Hashimoto, the creator of Ghostty and co-founder of HashiCorp. Its stated mission is to build "the multiplexer for all work", starting with a terminal multiplexer.
Who is on the Superlogical team?#
Per the company site: Mitchell Hashimoto, Jack Pearkes (HashiCorp's first employee and former VP of Engineering), Alasdair Monk (formerly at Poolside, Vercel, HashiCorp, and Heroku), and Hector Simpson (a designer with Poolside, Heroku, HashiCorp, Clearbit, and Vercel experience).
Is Superlogical built on Ghostty?#
It is built on libghostty, the MIT-licensed terminal library from Ghostty. Hashimoto says Ghostty remains an independent non-profit and that its mission, governance, license, and roadmap do not change.
What is Superlogical Rex?#
Rex is Superlogical's terminal multiplexer, the first product from Mitchell Hashimoto's new company. It keeps terminal sessions alive so you can close the app, reconnect from another device, and pick up where you left off, and it adds remote connections and program activity status.
When can I use Rex?#
Public testing began on October 5, 2026. Invites go out in waves to the mailing list on superlogical.com, and only the macOS app is in the test so far. Superlogical says it plans to work through the whole list in under a month, and a stable release will be downloadable without sharing contact details.
Is Rex free?#
Yes. Superlogical says Rex "is and will always be free", needs no account, and can be fully self-hosted. It has not announced its commercialization plan, but says the Rex clients and servers will not be directly monetized.
How is it different from tmux or zellij?#
Superlogical describes a more modern multiplexer with web and native macOS and iOS apps, built-in live session sharing, and native scrollback and selection. The larger plan is a durable session layer that also covers agents, background jobs, and production work. For a comparison of agent-aware multiplexers that exist today, see Herdr vs pi vs tmux.
Sources#
- Superlogical announcement - company website
- Mitchell Hashimoto's personal post on Superlogical - personal reflection and context
- Public testing is beginning - Superlogical's October 5, 2026 Rex announcement
- Rex Program Status Protocol (OSC 7501) - Rex docs
- Hacker News discussion (796 points, 458 comments as of October 9) - community reaction
- Ghostty non-profit announcement - Hashimoto's post on Ghostty's transfer to a non-profit
- libghostty documentation - the terminal library Superlogical builds on
Continue Reading#
- Mitchell Hashimoto on Building Ghostty in Zig - Our earlier interview analysis covering Hashimoto's terminal work and Zig choice
- Terminal Agents Are the New Developer Runtime - Why terminals matter more than ever as AI agent surfaces
- Warp Open-Sources Its Agentic Terminal Stack - Another terminal company making moves in the agent era
- Git Worktrees and Parallel Agent Development - Managing multi-session development workflows with agents
- DevDigest Redesign 2026 - How we rebuilt our own developer-facing surface
- Warp 2.0: The Agentic Development Environment
- Herdr vs pi vs tmux: Which Agent Harness Should You Run? - the agent-aware multiplexers you can use today
- Herdr Deep Dive - how an agent-aware multiplexer detects working and blocked agents from the screen
- Best CLI Tools for Developers - the terminal toolkit around multiplexers like tmux and zellij
- Claude Code - the terminal agent most multi-session setups are built to run
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