volar-docs/docs/package-api-reference.md

Volar Package API Reference

Docs Index • Repo README • Plugin Authoring • Volar Kit & Editor

This reference summarizes the primary exports and configuration points for the most-used Volar packages. Use it as a quick lookup when wiring custom tooling.

@volar/editor

Export	Description
createEditorConnection(languageService)	Wraps a LanguageService and exposes methods mirroring LSP features (languageFeatures, documents, commands). Ideal for custom editors that do not use JSON-RPC.
SnapshotDocument	Text document implementation that tracks versions and provides ts.IScriptSnapshot.
TextDocuments<T>	Manages a collection of documents, emits onDidOpen, onDidChangeContent, onDidClose, onDidSave events.
createUriMap()	Helper for URI-based maps used by documents/projects.

Usage Tips:

• Always call documents.listen() with your editor’s change events so the language service receives updates.
• Dispose documents when closed to release snapshots and avoid memory leaks.
• Use editor.connection.getWorkspaceEdit() to apply edits triggered by code actions/rename.

@volar/language-service

Export	Description
createLanguageService(language, plugins, env, project)	Core factory returning a LanguageService with context, languageFeatures, and commands.
LanguageServicePlugin	Interface for authoring plugins (see Plugin Authoring).
createUriMap, mergeWorkspaceEdits, transformWorkspaceEdit	Utility helpers used when composing plugins or handling edits.
FileSystem, LanguageServiceEnvironment	Shapes describing filesystem + configuration hooks for the service.

Capabilities: languageService.languageFeatures exposes methods corresponding to LSP requests: getDiagnostics, getCompletionItems, getHover, getDefinition, getCodeActions, etc.

@volar/language-core

Export	Description
createLanguage(plugins, scriptRegistry, sync)	Builds a Language instance that tracks virtual files/embedded codes emitted by language plugins.
forEachEmbeddedCode	Generator that iterates embedded files recursively.
LanguagePlugin	Interface for describing how to turn source files into virtual code (see Source Map & Code Gen).
defaultMapperFactory, LinkedCodeMap	Tools for building and traversing source maps.

Snapshots: Use language.scripts.get(id) to fetch scripts and language.scripts.set(id, snapshot, languageId) to register new ones.

@volar/typescript

Export	Description
createLanguageServiceHost(ts, sys, language, asScriptId, projectHost)	Bridges Volar’s Language with TypeScript’s LanguageServiceHost.
decorateLanguageServiceHost(host, opts)	Augments an existing TS host with Volar hooks.
createUriConverter(rootFolders)	Shared helper for converting between file paths and vscode-uri instances.
createSys	Builds a virtual ts.System that respects Volar’s FS abstraction.

TypeScript Plugin Hooks: Within a language plugin you can expose typescript.extraFileExtensions, types definitions, and getServiceScript to feed TS the generated files.

@volar/language-server

Export	Description
createServer(connection)	Low-level factory returning a server object (documents, workspaceFolders, fileWatcher, languageFeatures, etc.).
createConnection()	Convenience for creating a VS Code-style connection with proposed features enabled.
createSimpleProject(languagePlugins)	Minimal project implementation for non-TypeScript scenarios.
createTypeScriptProject(ts, tsLocalized, create)	Full-featured project that manages TS configs, watchers, and workspace diagnostics.

Features: server.languageFeatures.requestRefresh(clearDiagnostics) forces clients to refresh diagnostics (useful after config changes).

@volar/kit

Export	Description
createLanguageServer(options)	Batteries-included bootstrapper that wires connection, projects, configuration reloads, and restart commands.
createProjectFactory(opts)	Helper for building project loaders compatible with the kit.

Use @volar/kit when you want a ready-made server; drop down to @volar/language-server for custom wiring.

@volar/monaco

See Monaco Playground.

Key Helpers

Export	Description
setupLanguageServiceForMonaco(monaco, loaders)	Registers language service worker + TypeScript loader.
languageServiceHost (returned)	Provides writeFile, syncFile, renameFile helpers for your VFS.

loadTypescript and loadLanguageService should return promises so the worker bundles lazily.

@volar/cli (if used)

While not covered elsewhere, some community tools use @volar/cli as a thin wrapper around the language service. When writing your own CLI, follow the patterns in CLI Integration.

@volar/vue-language-core

Export	Description
createVueLanguagePlugin(ts, compilerOptions, vueCompilerOptions, asFileName)	Default language plugin for .vue SFCs.
getAllExtensions(vueCompilerOptions)	Returns file extensions treated as Vue components.
Utilities (parseSfc, compileTemplate, etc.)	Used when customizing SFC parsing/compilation.

Customize via vueCompilerOptions (macros, experimental flags). See TypeScript Plugin Deep Dive.

@volar/vue-language-service

Wraps @volar/language-service with Vue-specific plugins (template completions, directives, twoslash queries).

Export	Description
getFullLanguageServicePlugins(ts, opts)	Returns the default plugin array (TS semantics, CSS, Emmet, Vue-specific features).
getHybridModeLanguageServicePlugins(ts, getTsPluginClient)	Reduced set for hybrid environments (e.g., Take Over Mode).
getVueLanguagePlugin(ts, compilerOptions, vueCompilerOptions)	Convenience wrapper to create the language plugin.

Use these helpers when you want the stock Vue feature set without reconfiguring every service manually.

@volar/vue-typescript

TypeScript plugin that injects .vue support into tsserver.

Export	Description
createLanguageServerPlugin(ts, resolveConfig)	Entry point for wiring the plugin inside @volar/language-server / @volar/kit.
createTypeScriptPlugin(ts, config)	Low-level API for registering with tsserver directly.
resolveConfig(workspaceUri)	Hook for returning vueCompilerOptions per workspace.

See TypeScript Plugin Deep Dive for details.

@vue/language-core

Vue compiler utilities used under the hood by Volar. Key exports include:

• createTsLanguageServiceHost(ts, options) – used when invoking Vue’s TS integrations directly.
• compileScript, compileTemplate – SFC compilation helpers (useful when customizing macros or template transforms).
• parseSFC – parse .vue files into descriptor objects.

While Volar wraps most of these, advanced integrations may call them directly when customizing compile steps.

With this reference, you can quickly locate the right factory or helper for any integration scenario, complementing the narrative guides throughout the docs.