Subsystems

The internal building blocks that make a prompt happen, separate from the modules that produce the prompt's content. Where modules sit at the user-facing edge ("the rust module"), subsystems sit underneath ("the format-string parser").

Subsystem map

graph TD
    Main["src/main.rs<br/>CLI entry"] --> Print["Print<br/>(src/print.rs)"]
    Main --> InitScripts["Init scripts<br/>(src/init/)"]
    Main --> Configure["Configure<br/>(src/configure.rs)"]
    Main --> BugReport["Bug report<br/>(src/bug_report.rs)"]
    Print --> Context["Context<br/>(src/context.rs)"]
    Print --> Formatter["Formatter<br/>(src/formatter/)"]
    Context --> Config["Configuration<br/>(src/config.rs + src/configs/)"]
    Print --> Logger["Logger<br/>(src/logger.rs)"]
    Print --> Statusline["Statusline integration<br/>(src/utils/statusline.rs)"]
    Configure --> Config

Pages

Subsystem	Page	What lives there
Context	Context	The Context struct, properties, target, repo discovery, dir scanning
Configuration	Configuration	TOML loading, StarshipConfig, FullConfig, ModuleConfig trait, palette and style parsing, JSON Schema generation
Format string DSL	Formatter	The pest grammar, StringFormatter, VersionFormatter
Init scripts	Init scripts	The two-phase init, per-shell quirks
Presets	Presets	The preset system, build.rs codegen, packaged TOML files
Logger	Logger	The STARSHIP_LOG runtime logger
Bug report	Bug report	The starship bug-report flow
Statusline integration	Statusline	The starship statusline claude-code path
Configure subcommands	Configure	The starship config, print-config, toggle subcommands

Why split this way?

The repository's source tree is a flat src/ with one giant modules/ directory. Splitting subsystems off helps explain the parts that are not modules — the parsing, configuration, runtime, and integration layers that all modules depend on. If you're adding a module, focus on Modules. If you're touching the engine itself, this section is for you.