48 chapters · PDF + EPUB fact-checked

The tmux Book

Internals, Automation, Extension Engineering, and Production Operations.

Coming soon

tmux is a persistent server with its own protocol, command language, and terminal engine. The book traces those pieces through a pinned C source tree and test suite while keeping documented behavior separate from implementation details. It shows how windows, winlinks, and panes relate in memory, how PTY output reaches a terminal, and why commands can finish out of order.

By Wolfgang Kerschbaumer

Status: all 48 chapters and 5 appendices are drafted and fact-checked (about 126,000 words). Runtime verification and external publication remain.

Get notified when it ships More from Sysinit Press

First edition ships DRM-free as PDF and EPUB, with free updates.

01 Contents

How tmux works behind the command line.

The first half explains tmux's object model, command parser, queues, and terminal engine. Later chapters cover automation, a complete configuration, plugin internals, and operational patterns. Open a part to see its chapters.

Preface

What this book assumes, and how to read it

Part 1 Foundations and Architecture 5 chapters

1 Why tmux
2 Building and Reading tmux
3 Clients, Servers, Sockets, and Protocol
4 The Object Graph
5 Events, Lifetimes, and Deferred Work

Part 2 Command, Configuration, and Policy Engines 7 chapters

6 The tmux Command Language
7 Arguments, Targets, and Context
8 The Command Queue
9 Configuration Loading and Reloading
10 Options, Scopes, Arrays, and Defaults
11 Formats, Styles, and Format Jobs
12 Keys, Tables, Hooks, and Mouse Events

Part 3 The Terminal Engine 10 chapters

13 The Terminal Engine
14 Spawning Panes and Owning PTYs
15 The Input State Machine
16 Characters, Cells, Colours, and Attributes
17 Screens, Grids, History, and Reflow
18 Layouts, Geometry, and Resize
19 Redraw, Damage, and TTY Output
20 Terminal Capabilities, Keys, and Colour Negotiation
21 Status Lines, Prompts, Menus, Popups, and Modes
22 Clipboard, Hyperlinks, and Images

Part 4 Expert Operation and Automation 5 chapters

23 Operating Sessions, Windows, and Panes
24 Copy Mode, Buffers, and Selection Semantics
25 Control Mode and Machine Interfaces
26 Named Servers, Multiuser Access, and Security
27 Performance, Diagnosis, Upgrade, and Recovery

Part 5 A Real Configuration Under the Microscope 4 chapters

28 Configuration Architecture and Load Order
29 The Local Key Model
30 Status, Formats, Hooks, and Naming
31 tmuxp, Shell, and Agent Integrations

Part 6 Extension Internals 13 chapters

32 The Plugin Surface and TPM
33 tmux-sensible
34 tmux-yank
35 tmux-logging
36 tmux-pain-control
37 tmux-jump
38 tmux-fingers
39 tmux-fzf-url
40 extrakto
41 tmux-pop
42 tmux-power-zoom
43 tmux-command-palette
44 tmux-window-name

Part 7 Production Patterns and Extension Engineering 4 chapters

45 The Incident-Response Workspace
46 Remote, Nested, SSH, and Mosh Workflows
47 Development, CI, and Declarative Sessions
48 Engineering and Auditing Extensions

Part 8 Appendices 5 appendices

A Troubleshooting Field Guide
B Commands, Options, Hooks, Formats, and Key Tables
C Terminal Protocol and terminfo Field Guide
D Sources, Reproducibility, Verification, and Version Migration
E Glossary and Generated Subject Index

02 Who it's for

For engineers who already live in tmux.

This book is for developers, SREs, and platform engineers who use terminals professionally. It assumes basic tmux familiarity and comfort with processes, PTYs, and event loops. The book explains its source-reading workflow.

Written for

Users who want to predict and automate tmux: control mode, named servers, formats, hooks, and declarative sessions.
Operators who debug rendering, keys, colors, and capability problems with evidence rather than restarts.
Plugin authors and auditors who want to read extensions as programs, with one source-level chapter per plugin.

Coming soon.

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