Getting Started

zline is an ultra-fast, zero-dependency, pure-Zsh replacement for Powerlevel10k and Starship designed for sub-millisecond synchronous rendering and zero subshell forks.

Installation

Using zload (recommended for sub-millisecond warm startup):

~/.zshrc

plugins=(
  casonadams/zline
)
zload "${plugins[@]}"

Manual Git clone installation:

Terminal

git clone https://github.com/casonadams/zline.git ~/.zline
echo 'source ~/.zline/zline.zsh' >> ~/.zshrc
echo 'zline preset powerline --transient' >> ~/.zshrc
echo 'zline init' >> ~/.zshrc

Core Architecture & Performance Invariants

Strict Zero-Fork Path

Prompt rendering strictly executes 0 subprocesses and 0 subshell forks $(...) on the synchronous path. All string processing relies on native Zsh parameter expansions.

Compile Once, Render Microseconds

When zline init runs, token arrays are compiled into direct function pointers, eliminating zparseopts and argument-parsing overhead at prompt render time.

Async Background Worker

Slow I/O operations (such as deep Git status scans) run asynchronously in a dedicated non-blocking worker over FIFOs/pipes without blocking your prompt.

Base16 Palette First

Standardizes on ANSI colors 0 through 15 so prompt themes automatically adapt to your terminal's color scheme without hardcoded RGB values.

Configuration & Array Syntax

Prompts are declared using native Zsh token arrays. You do not need quotes around lines unless an argument contains spaces:

~/.zshrc

zline_left=(
  dir --shorten 1 --anchor git
  git --clean 2 --dirty 3 --icon " "
  rust --icon ""
  package
  newline
  prompt_char
)

zline_right=(
  exec_time --min 2
  time --color cyan
)

Universal Segment Flags

Every built-in and custom segment accepts these universal modifiers:

Flag	Target	Default	Description & Example
`--icon <glyph>`	Any Segment	Built-in glyph	Overrides the default icon (e.g. `--icon " "`).
`--icon ""`	Any Segment	—	Suppresses the icon, rendering only text/content.
`--color <col>` `--fg <col>`	Any Segment	Theme Default	Sets foreground color: Base16 index (`0-15`), color name (`cyan`), or hex (`#38bdf8`).
`--bg <col>`	Any Segment	Theme Default	Sets background block color in Powerline and Rainbow visual styles.
`--prefix <str>`	Any Segment	None	String prepended immediately before the segment content.
`--suffix <str>`	Any Segment	None	String appended immediately after the segment content.
`--format <fn>`	Any Segment	None	Passes raw content to custom Zsh function which mutates `$REPLY`.

Global Styling Flags

Passed to zline preset <name> [flags] or zline style <name> [flags]:

Flag	Default	Description
`--transient`	Off	Collapses prompt history into a compact symbol upon executing a command.
`--transient-dir`	Off	Retains current working directory along with symbol in transient prompt history.
`--no-transient`	On	Disables transient prompt behavior (preserves full prompt in terminal scrollback).
`--no-icons` / `--icons`	Icons On	Toggles icon glyphs globally across all prompt segments.
`--ascii`	NerdFont	Renders ASCII-safe separators (`>`) for minimal or standard terminal fonts.
`--nerdfont`	NerdFont	Enables high-resolution Nerd Font Powerline glyphs (``, ``, ``).
`--frame [full\|left\|none]`	none	Draws framing line around multi-line prompt layouts.
`--connect`	Off	Draws connecting line between left and right prompt segments.
`--no-osc`	OSC On	Disables OSC 133 semantic prompt annotations and OSC 7 directory tracking.

Visual Presets & Curated Themes

Layout Presets

Preset	Visual Style	Command
Powerline	Classic solid block backgrounds with interlocking arrow glyphs.	`zline preset powerline`
Lean	Minimalist two-line prompt with pure colors and zero background blocks.	`zline preset lean`
Rainbow	Vibrant rounded pill segments with distinct functional color grouping.	`zline preset rainbow`
Pure	Clean, uncluttered, prompt-symbol-first modern aesthetic.	`zline preset pure`

Curated Base16 Color Themes

Theme	Palette Style	Command
Catppuccin	Soothing pastel dark palette with Mocha accents.	`zline preset catppuccin`
Tokyo Night	Dark, vibrant aesthetic inspired by Tokyo nightlife.	`zline preset tokyonight`
Nord	Arctic, north-bluish clean and muted palette.	`zline preset nord`
Gruvbox	Warm retro groove color scheme with rich contrast.	`zline preset gruvbox`

Command Line Interface

Complete reference of zline commands:

Command	Arguments / Flags	Description
`zline preset <name>`	`[--transient] [--ascii] [--no-icons]`	Loads layout preset or curated theme with optional styling flags.
`zline preset list`	—	Lists all available presets and curated themes.
`zline preset show <name>`	—	Displays the full Zsh configuration code for a preset.
`zline style <name>`	`[styling flags]`	Applies visual frame, separators, or mode overrides without reloading segments.
`zline init`	—	Compiles prompt tokens into wordcode and attaches shell lifecycle hooks.
`zline bench`	`[--profile] [iterations]`	Measures render latency against < 1.5 ms budget, with optional per-segment profiling.
`zline compare`	—	Runs comparative microbenchmarks against other prompt architectures.
`zline doctor`	—	Runs health check on Zsh version, UTF-8 locale, cache directory, and segments.
`zline configure`	—	Interactive CLI configuration wizard.
`zline migrate <file>`	`~/.p10k.zsh`	Translates Powerlevel10k configurations into native zline syntax.
`zline compile`	—	Compiles all zline modules into wordcode (`.zwc`) for instant loading.
`zline clean`	—	Removes compiled wordcode bytecode artifacts.
`zline update`	—	Pulls the latest git release and recompiles bytecode.
`zline notify`	`[on\|off\|threshold\|status]`	Configures desktop notifications for long-running commands (OSC 777 / OSC 9).
`zline version`	—	Prints current zline version.

Built-in Segments Directory (58 Segments)

zline ships with 58 built-in segments covering source control, system monitoring, cloud infrastructure, and 26+ programming language runtimes.

dir VCS & FS

Working directory with fish-style shortening, Git root anchoring, path aliasing, and read-only lock indicator.

--shorten 1 | --anchor git | --alias key=val | --readonly-icon

git VCS & FS

Instant synchronous HEAD branch read (< 0.1 ms) + non-blocking async worker badges for dirty, ahead/behind, stash, and submodules.

--clean 2 | --dirty 3 | --ahead 12 | --submodule | --stash

jj VCS & FS

Jujutsu VCS repository change ID and bookmark tracking from active .jj/ working copy.

Trigger: .jj/

status System

Command exit code badge with error signal translation and conditional zero suppression.

--hide-zero | --color 9

exec_time System

Execution duration of last command with minimum threshold gating and decimal precision controls.

--min 2 | --precision 2

prompt_char System

Dynamic prompt symbol with color state tracking for successful exit, error code, and Vi mode.

--symbol '❯' | --error '❯'

vi_mode System

Zsh Line Editor (ZLE) modal editing mode badge tracking NORMAL, INSERT, and VISUAL keymaps.

--normal NOR | --insert INS | --hide-insert

shlvl System

Nested shell depth warning alert displayed when $SHLVL exceeds configurable threshold.

--threshold 2 | --warn 9

jobs System

Active background job counter indicator tracking asynchronous processes suspended or running in current shell.

Pure Zsh builtin (%j)

time System

Current local time formatted with zero-fork prompt expansion escapes (e.g. %*, %T, %D).

--format '%*'

os System

Operating system and Linux distribution identification with matching logo glyphs.

--text

user_host System

User and hostname indicator automatically surfacing for SSH remote sessions or root user privileges.

SSH & UID == 0 detection

container System

Container runtime environment badge identifying Docker, Podman, LXC, systemd-nspawn, or WSL.

Trigger: /.dockerenv | /run/.containerenv

battery System

Hardware battery level percentage and charging state with configurable low-battery alert threshold.

--warn 20

ram System

System physical memory utilization percentage with warning color thresholding.

--warn 80

load System

System 1-minute CPU load average with configurable warning threshold.

--warn 4.0

k8s Cloud

Active Kubernetes cluster and namespace parsed directly from ~/.kube/config.

Trigger: ~/.kube/config

docker Cloud

Active Docker context name read from $DOCKER_CONTEXT or ~/.docker/config.json.

Trigger: Dockerfile | compose.yaml

aws Cloud

Active AWS profile and configured region read from environment variables or ~/.aws/config.

Trigger: $AWS_PROFILE | ~/.aws/

gcp Cloud

Active Google Cloud Platform project name extracted from $CLOUDSDK_CORE_PROJECT or active gcloud configuration.

Trigger: $CLOUDSDK_CORE_PROJECT | ~/.config/gcloud/

azure Cloud

Active Microsoft Azure subscription name from $ARM_SUBSCRIPTION_NAME or azure profile.

Trigger: $AZURE_CONFIG_DIR | ~/.azure/

terraform Cloud

Active Terraform workspace read from $TF_WORKSPACE or .terraform/environment.

Trigger: *.tf | .terraform/

pulumi Cloud

Active Pulumi stack and project configuration parsed from Pulumi.yaml.

Trigger: Pulumi.yaml

helm Cloud

Helm chart name and release version parsed from Chart.yaml or helmfile.yaml.

Trigger: Chart.yaml | helmfile.yaml

cmake Cloud

CMake project name and minimum version parsed from CMakeLists.txt or presets.

Trigger: CMakeLists.txt | CMakePresets.json

meson Cloud

Meson C/C++ project name and release version parsed from meson.build.

Trigger: meson.build

bazel Cloud

Bazel monorepo workspace name parsed from MODULE.bazel or WORKSPACE.

Trigger: MODULE.bazel | WORKSPACE | BUILD

rust Runtime

Rust toolchain release version parsed from rust-toolchain, rust-toolchain.toml, or Cargo.toml.

Trigger: Cargo.toml | rust-toolchain.toml

golang Runtime

Go runtime version parsed from go.mod directive or local Go toolchain.

Trigger: go.mod | *.go

node Runtime

Node.js version read from .node-version, .nvmrc, or package.json engines.

Trigger: package.json | .nvmrc | .node-version

bun Runtime

Bun runtime version or project badge detected from bun.lockb or bunfig.toml.

Trigger: bun.lockb | bunfig.toml

deno Runtime

Deno runtime version or project badge detected from deno.json or deno.lock.

Trigger: deno.json | deno.jsonc | deno.lock

venv Runtime

Python virtual environment, Conda environment, or Poetry project indicator.

Trigger: $VIRTUAL_ENV | $CONDA_DEFAULT_ENV | .venv

ruby Runtime

Ruby version detected from .ruby-version, Gemfile, or .tool-versions.

Trigger: Gemfile | .ruby-version

java Runtime

Java JDK version parsed from .java-version, pom.xml, or active $JAVA_HOME.

Trigger: pom.xml | build.gradle | .java-version

kotlin Runtime

Kotlin compiler version parsed from build.gradle.kts or .tool-versions.

Trigger: *.kt | *.kts | build.gradle.kts

scala Runtime

Scala language version parsed from build.sbt or .tool-versions.

Trigger: build.sbt | *.scala

swift Runtime

Swift compiler and Swift Package Manager version from Package.swift.

Trigger: Package.swift | *.swift

dart Runtime

Dart SDK and Flutter version parsed from pubspec.yaml or .tool-versions.

Trigger: pubspec.yaml | *.dart

zig Runtime

Zig toolchain version parsed from .zigversion, build.zig, or build.zig.zon.

Trigger: build.zig | .zigversion

php Runtime

PHP runtime version read from .php-version or composer.json.

Trigger: composer.json | .php-version

elixir Runtime

Elixir runtime version parsed from mix.exs or .tool-versions.

Trigger: mix.exs | *.ex | *.exs

erlang Runtime

Erlang/OTP version parsed from rebar.config or .tool-versions.

Trigger: rebar.config | *.erl

julia Runtime

Julia environment release version parsed from Project.toml or .tool-versions.

Trigger: Project.toml | *.jl

crystal Runtime

Crystal language runtime version from shard.yml or .tool-versions.

Trigger: shard.yml | *.cr

clojure Runtime

Clojure project environment from deps.edn, project.clj, or .tool-versions.

Trigger: deps.edn | project.clj | *.clj

haskell Runtime

Haskell GHC compiler version parsed from stack.yaml, cabal.project, or .tool-versions.

Trigger: stack.yaml | *.cabal | *.hs

ocaml Runtime

OCaml toolchain version parsed from dune-project, dune, or .tool-versions.

Trigger: dune-project | *.ml

solidity Runtime

Solidity smart contract workspace parsed from foundry.toml or hardhat.config.js.

Trigger: foundry.toml | hardhat.config.js | *.sol

perl Runtime

Perl version parsed from cpanfile or .tool-versions.

Trigger: cpanfile | *.pl | *.pm

r Runtime

R environment version detected from DESCRIPTION, .Rprofile, or renv.lock.

Trigger: DESCRIPTION | renv.lock | *.R

dotnet Runtime

.NET SDK release version parsed from global.json or project solution.

Trigger: global.json | *.csproj | *.fsproj

lua Runtime

Lua runtime release version from .lua-version or .tool-versions.

Trigger: .lua-version | *.lua

package Environment

Application package version extracted from package.json, Cargo.toml, or pyproject.toml.

Trigger: package.json | Cargo.toml | pyproject.toml

direnv Environment

Active Direnv loaded environment indicator triggered by $DIRENV_DIR or .envrc.

Trigger: $DIRENV_DIR | .envrc

mise Environment

Active mise polyglot runtime environment indicator from $MISE_ENV or mise.toml.

Trigger: mise.toml | .tool-versions

nix_shell Environment

Active Nix development shell indicator from $IN_NIX_SHELL or default.nix.

Trigger: $IN_NIX_SHELL | flake.nix | shell.nix

text Environment

Static text badge or evaluated shell variable (e.g. text "PRODUCTION" --color 9).

text <content> [--color <col>]