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dev-mux vs pi-web (and firstmate)

Q: What is the difference between pi-web and dev-mux?

pi-web is a free, MIT-licensed web cockpit for the Pi coding harness, with a gateway that federates multiple machines one-at-a-time; it requires a Node 22 daemon per machine and only supports Pi. dev-mux is a commercial, harness-agnostic fleet control plane: a hub keeps one live, freshness-aware map of every machine and agent, spokes need only bash + tmux + git, and surfaces include browser, TUI, iOS, glasses, and Telegram.

Q: Is firstmate a dev-mux alternative?

Not really — it's complementary. firstmate orchestrates a crew of agents inside a session backend (tmux by default) on one box, with no UI or fleet layer. Its tmux crews are exactly the kind of sessions a dev-mux hub watches, so it slots inside a spoke rather than replacing the plane.

Q: Is there a free fleet control plane for coding agents?

pi-web is the closest free option if you're Pi-only and accept machine-at-a-time federation. There's no free equivalent of an always-on, harness-agnostic hub with freshness semantics and mobile push — that's the infrastructure dev-mux charges for.

pi-web is the closest free analogue to dev-mux's browser cockpit: persistent server-side sessions for the Pi coding harness, supervised from a browser or phone, with a “Fleet” mode that federates multiple machines behind one gateway. It's MIT, solo-built, and moving fast. The differences are real, though: pi-web is Pi-only and machine-at-a-time; dev-mux is harness-agnostic and holds the whole fleet in one live map.

TL;DR — If you're all-in on the Pi harness and comfortable running a Node 22 daemon on every box, pi-web is a genuinely good free cockpit. If you run Claude Code (or a mix of agents), want one always-fresh view of every machine at once rather than a machine switcher, and prefer a bash-floor spoke over a daemon install — that's dev-mux.

What pi-web actually is (and where firstmate fits)

pi-web is an npm package (Node ≥22) installing a per-user session daemon and web server on each machine, organized as Machine → Project → Workspace (a git worktree) → Session, with transcript history, context/cost tracking, and real-time redirecting — deep, but Pi-only (pinned to a Pi minor version). Fleet mode makes one instance a gateway that proxies to other registered runtimes (ideally over Tailscale) — you pick a machine, then browse it. firstmate is a different animal worth knowing: not a server but an agent-orchestration layer — skills, scripts, and a bash watcher that wakes a supervisor agent when a crewmate needs attention, running on top of tmux (or herdr/zellij). It's what a power user might run inside dev-mux spokes, not instead of dev-mux.

At a glance

As of July 31, 2026. If something here is stale, tell us.

	dev-mux	pi-web
What it is	Harness-agnostic fleet control plane	Pi-harness web cockpit with machine federation
Agents	Tuned for Claude Code; transport is agent-agnostic	Pi only (pinned minor version)
Multi-machine model	One live, freshness-aware map of all boxes at once	Gateway proxies to one selected machine at a time
Machine floor	bash 3.2 + tmux + git	Node ≥22 daemon + web server per machine
Attention	Hook-level signals + push, fleet-wide	Session status while you're looking; Pi-specific
Cost tracking	Usage dials across providers	Pi context/cost per session (deep)
Surfaces	Browser, TUI, iOS, glasses, Telegram	Browser (phone via browser)
Backing / price	Commercial product — Solo $25/mo	Free, MIT, solo-maintained

Where pi-web (and firstmate) shine

pi-web's Pi depth — transcripts, context usage, and per-session cost for the Pi harness go deeper than any generic tool.
Real federation, for free — the gateway genuinely reaches sessions on other machines; for a Pi-only fleet it may be all you need.
firstmate's supervision model — an event-driven watcher that wakes a supervisor agent only when a crewmate needs a real decision is a clever, token-frugal pattern — and it runs happily inside tmux sessions on dev-mux spokes.

Where dev-mux is a different layer

One map, not a switcher. pi-web's Fleet mode routes you to a machine; dev-mux's hub aggregates every machine into a single freshness-aware view — you see the whole herd's state before choosing where to look.
Harness-agnostic. dev-mux watches whatever runs in tmux — Claude Code today, anything terminal-driven tomorrow. pi-web is bound to Pi's release cadence by design.
Floor, not runtime. A spoke needs bash + tmux + git; pi-web needs a Node 22 daemon on every box you federate.
Beyond the browser. TUI for terminal people, a native iOS app with push, glasses, Telegram — and a company behind the product.

Common questions

What is the difference between pi-web and dev-mux?

pi-web: free Pi-only cockpit, Node-22 daemon per box, machine-at-a-time federation. dev-mux: harness-agnostic control plane, one live map of everything, bash-floor spokes, surfaces from browser to glasses.

Is firstmate a dev-mux alternative?

Not really — complementary. firstmate orchestrates a crew inside tmux on one box, no UI or fleet layer; its crews are exactly the sessions a dev-mux hub watches.

Is there a free fleet control plane for coding agents?

pi-web, if you're Pi-only and accept machine-at-a-time federation. An always-on, harness-agnostic hub with freshness and push is the part nobody offers free — that's what dev-mux charges for.

Federating machines is a start. Watching the whole herd at once is the point.

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Written 2026-07-31 against pi-web's site and repo, and the firstmate repo. pi-web is a trademark of its owners; no affiliation or endorsement implied. Corrections welcome.