Plugin System Overview

typewriter v0.5.2 introduced a dynamic plugin architecture. In v1.0.0 this remains experimental: local plugin loading is available, but there is no plugin add command, registry marketplace, or stable community plugin ABI.

How It Works

Plugin authors implement the EmitterPlugin trait from the typewriter-plugin crate
Plugins are compiled as shared libraries (.so / .dylib / .dll)
The CLI dynamically loads plugins at startup via libloading
Plugins provide TypeMapper implementations just like built-in emitters

Architecture

┌─────────────────┐       ┌──────────────────┐
│  typebridge CLI │──────▶│  PluginRegistry   │
└─────────────────┘       └────────┬─────────┘
                                   │
                    ┌──────────────┼──────────────┐
                    ▼              ▼              ▼
            ┌──────────┐  ┌──────────┐  ┌──────────┐
            │   Ruby   │  │   PHP    │  │   Dart   │
            │  .so/.dll│  │  .so/.dll│  │  .so/.dll│
            └──────────┘  └──────────┘  └──────────┘

Key Components

Component	Crate	Purpose
`EmitterPlugin` trait	`typewriter-plugin`	Interface for plugin implementations
`declare_plugin!` macro	`typewriter-plugin`	Generates C ABI entry points
`PluginRegistry`	`typewriter-engine`	Loads and manages plugins
`PluginConfig`	`typewriter-plugin`	Plugin-specific config from TOML

Bundled Plugins

Plugin	Language ID	Extension	Description
`typewriter-plugin-ruby`	`ruby`	`.rbi`	Sorbet type signatures
`typewriter-plugin-php`	`php`	`.php`	PHP 8.1+ readonly classes
`typewriter-plugin-dart`	`dart`	`.dart`	json_serializable classes

Limitations

CLI only — plugins are loaded at CLI startup, not during cargo build proc-macro expansion
No hot reload — plugins are loaded once; restart CLI after changes
ABI versioning — plugins must match PLUGIN_API_VERSION, and the ABI is not stable in v1.0.0