tmtv 3.0.0 — More of your terminal, shared
3.0.0 · 27 October 2026
A shared terminal should carry the context that makes your work understandable: the pane layout, the character you typed, the link in the output. tmtv 3.0 moves to a pinned tmux 3.8 core and introduces sharing protocol 11 to carry more of that context between the host and relay.
Use it to pair on a fix, walk a teammate through a failing command, or teach a workflow live. Guests can join over SSH without installing tmtv. Enable web sharing when a browser is the easier way in.
What changes in 3.0
Modern tmux, shared
The tmux 3.8 migration brings a newer terminal core and richer layout transfers, including layout hierarchy, floating panes and linked-window state. Supported state travels through bounded, validated snapshots; if a live layout cannot be represented, sharing ends with an explicit error instead of silently leaving viewers out of sync. Local terminal operation does not require a sharing connection.
A more complete picture after reconnecting
Reconnect restoration carries supported screen and parser state, text attributes, OSC 8 hyperlinks and SIXEL images. The browser waits for its image decoder before replaying output. Full-width copy-mode cursor and selection positions are preserved, and unsafe snapshot metadata is rejected before it can partially change receiver state.
Snapshots have explicit size and history limits. They are not an unlimited terminal archive or a promise that every possible tmux state can be shared. See the snapshot protocol and limits.
Type what you mean
Unicode keystrokes travel as Unicode scalar values rather than process-local tmux identifiers, including emoji and private-use characters. Key modifiers are retained. Pasted UTF-8 travels as literal bytes; bracketed-paste delimiters are forwarded only when the receiving application has enabled bracketed paste.
Familiar ways to work together
SSH sharing, separate read-only and read-write tokens, optional browser access, asciinema recording and self-hosting remain part of tmtv. These are existing capabilities, not features introduced by 3.0.
Browser sharing and browser input are separate opt-ins. Read-only viewers cannot type and do not receive shared clipboard access. Treat tokens as credentials; named public URLs are not secret access controls. The relay processes terminal data, so choose a relay you trust or host your own.
Upgrading: host and relay move together
Protocol 11 is incompatible with tmtv 2.x and earlier develop protocol versions. A v3 host cannot share through a v2 relay, and a v2 host cannot share through a v3 relay. Ordinary SSH viewer applications require no tmtv installation or upgrade.
The public tmtv.se relay was upgraded to 3.0.0 on 27 October 2026. If you use the public service, upgrade your hosting client to 3.0.0; SSH guests do not need to install or upgrade tmtv. You can check the relay’s current version at the health endpoint.
For a self-hosted relay, prepare matching host and relay binaries and web assets, then switch them in a planned maintenance window:
- Save work and arrange the interruption with your collaborators.
- Keep the previous host binary, relay binary and web assets for rollback.
- Upgrade the relay and hosting clients together.
- Restart running hosts and distribute their new invitation links.
Replacing the executable does not update a running host. Restarting a host ends its local tmux server and may terminate programs in its panes. A fresh host creates new sharing credentials and links. Automatic reconnects of the same running host retain their identity; an incompatible relay upgrade does not migrate live sessions.
Rollback also requires matching old host, relay and web assets and restarted hosts. New-version sessions and links cannot be preserved by that rollback. Operators should follow the release procedure.
Validation and rollout
The release workflow validates the complete twelve-binary manifest and checksums, authenticated SSH transport, and Chromium, Firefox and Linux WebKit rendering and reconnects. Linux and native Intel and Apple Silicon host regressions also run.
The public relay was upgraded to 3.0.0 on 27 October 2026. Release publication and production deployment are separate operations for self-hosted services.
Built on good foundations
Thanks to the tmux and tmate communities whose work makes tmtv possible, and to everyone trying it in real sessions. tmtv remains open source under the ISC license.