# API reference Source: https://libtmux.org/en/kotlin/latest/reference/ > Types, methods, and functions in libtmux for Kotlin. Kotlin API Find a type or member Browse the Kotlin types and operations for working with tmux. Start with the core objects below, or search for a type or member. Server 2 types, 1 function or constant [Server 49 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-server/) Manages sessions, windows, and panes on a tmux server. [LibTmuxDsl annotation](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-libtmuxdsl/) Marks every builder below so an inner block cannot reach an outer block's receiver by accident: `split { directory = x }` inside `window { }` resolves to the innermost [`SplitBuilder` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-splitbuilder/), never to the [`WindowBuilder` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-windowbuilder/)it is nested in. Reaching the outer receiver on purpose still works, spelled explicitly (`this@window.directory = x`). [withServer function](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-withserver/) Opens a [`Server` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-server/), runs [`block` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-withserver/#io.github.libtmux.kotlin.withServer.parameter.block), and closes it — even if [`block` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-withserver/#io.github.libtmux.kotlin.withServer.parameter.block)throws or is cancelled. Session 2 types [Session 26 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-session/) A tmux session and its captured windows and properties. [SessionBuilder 5 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-sessionbuilder/) Configure a new session, its initial command, and its windows with [`Server.newSession` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-server-newsession/). Window 2 types [Window 38 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-window/) A tmux window at a specific position in a session. [WindowBuilder 5 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-windowbuilder/) Configure a window and its pane splits inside a [`SessionBuilder` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-sessionbuilder/)block. Pane 1 type [Pane 53 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-pane/) A tmux pane, with operations for input, output, and layout. Client 1 type [Client 15 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-client/) An attached tmux client and its captured properties. Hooks 1 type [Hooks 10 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-hooks/) Read and update hooks for the server, session, window, or pane that owns this handle. Options — Functions 2 functions and constants [orNull function](https://libtmux.org/en/kotlin/latest/reference/java-util-optionalint-ornull/) java.util.OptionalInt The value, or null when absent: an exit status, a captured server pid. [orNull function](https://libtmux.org/en/kotlin/latest/reference/java-util-optionallong-ornull/) java.util.OptionalLong The value, or null when absent. Keys and bindings 1 type [Keys 9 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-keys/) The server's key bindings, in one key table or across all of them. Buffers 1 type [Buffers 11 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-buffers/) The tmux server's paste buffers. Layout and geometry 1 type [SplitBuilder 8 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-splitbuilder/) Choose the position, size, and working directory of a new pane split. Environment 1 type [Environment 14 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-environment/) Read and update environment variables used to start processes in tmux. Commands 7 types, 1 function or constant [Batch 9 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-batch/) Several tmux commands collected to run together in one invocation. [CommandChain 13 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-commandchain/) A sequence of tmux commands where each one acts on what the last one made. [Commands 6 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-commands/) The commands this tmux knows, read without starting a server to answer. [ExecutionPolicy 4 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-executionpolicy/) Controls the dispatchers and concurrency limits for a [`Server` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-server/)'s suspending operations. [MessageLog 6 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-messagelog/) The server's own message log, newest last. [Prompt 7 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-prompt/) The server's command-prompt history. [Shell 8 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-shell/) A shell command run by tmux, and a tmux command chosen by a shell command's exit status. [retryIfSafe function](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-retryifsafe/) Retries [`block` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-retryifsafe/#io.github.libtmux.kotlin.retryIfSafe.parameter.block)up to [`times` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-retryifsafe/#io.github.libtmux.kotlin.retryIfSafe.parameter.times)more times after a [`DispatchException` ](https://libtmux.org/en/java/latest/reference/io-github-libtmux-exception-dispatchexception-dispatchexception/)whose [`DispatchException.safeToRetry` ](https://libtmux.org/en/java/latest/reference/io-github-libtmux-exception-dispatchexception-dispatchexception-safetoretry/)says the exact same request can be sent again. Control mode 1 type, 3 functions and constants [ControlClient 11 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-controlclient/) A tmux client that stays attached and answers one command at a time. [await function](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-channel-await/) Waits for something to signal this channel. [awaitReservingCapacity function](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-channel-awaitreservingcapacity/) As [`await` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-channel-await/), while preserving process capacity for a call that signals it. [withControl function](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-withcontrol/) As [`withServer` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-withserver/), for a [`ControlClient` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-controlclient/)attached through [`server` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-withcontrol/#io.github.libtmux.kotlin.withControl.parameter.server). Queries 2 functions and constants [filter function](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-iterable-filter/) Selects the elements an expression matches. [not function](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-query-filterexpr-not/) Inverts an expression, so `!Pane_.active().isTrue()` says what it means. Queries — Fields 5 types [TextField 7 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-textfield/) Kotlin-idiomatic wrappers over [`Fields` ](https://libtmux.org/en/java/latest/reference/io-github-libtmux-query-fields-fields/)' typed field handles, each holding the Java handle it wraps. A value class, so this costs nothing beyond the Java object it already holds — the same choice [`io.github.libtmux.kotlin.Server` ](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-server/)'s live handles reject, made here on purpose: a field handle carries exactly one property, which is what makes the boxing tradeoff free. [NumberField 6 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-numberfield/) Build numeric comparisons for a captured tmux field. [FlagField 2 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-flagfield/) Match a captured boolean field against true or false. [ToManyField 3 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-tomanyfield/) Match an object by the captured children related to it. [ToOneField 1 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-toonefield/) Match an object by one captured related object. Constants and enums 1 type [Options 13 members](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-options/) Read and update options for the server, session, window, or pane that owns this handle. ## By module 8 modules * java.util.OptionalInt 1 * [or​Null](https://libtmux.org/en/kotlin/latest/reference/java-util-optionalint-ornull/) * java.util.OptionalLong 1 * [or​Null](https://libtmux.org/en/kotlin/latest/reference/java-util-optionallong-ornull/) * io.github.libtmux.Channel 2 * [await](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-channel-await/) * [await​Reserving​Capacity](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-channel-awaitreservingcapacity/) * io.github.libtmux.kotlin 25 * [Batch](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-batch/) * [Buffers](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-buffers/) * [Client](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-client/) * [Command​Chain](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-commandchain/) * [Commands](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-commands/) * [Control​Client](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-controlclient/) * [Environment](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-environment/) * [Execution​Policy](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-executionpolicy/) * [Hooks](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-hooks/) * [Keys](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-keys/) * [Message​Log](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-messagelog/) * [Options](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-options/) * [Pane](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-pane/) * [Prompt](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-prompt/) * [Server](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-server/) * [Session](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-session/) * [Session​Builder](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-sessionbuilder/) * [Shell](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-shell/) * [Split​Builder](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-splitbuilder/) * [Window](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-window/) * [Window​Builder](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-windowbuilder/) * [Lib​Tmux​Dsl](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-libtmuxdsl/) * [retry​If​Safe](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-retryifsafe/) * [with​Control](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-withcontrol/) * [with​Server](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-withserver/) * io.github.libtmux.kotlin.Iterable 1 * [filter](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-iterable-filter/) * io.github.libtmux.kotlin.query 5 * [Flag​Field](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-flagfield/) * [Number​Field](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-numberfield/) * [Text​Field](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-textfield/) * [To​Many​Field](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-tomanyfield/) * [To​One​Field](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-query-toonefield/) * io.github.libtmux.query.FilterExpr 1 * [not](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-query-filterexpr-not/) * Types 1 * [Lib​Tmux​Dsl](https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-libtmuxdsl/)