VS Code API Coverage

Authoritative map of every top-level vscode.* API surface and its implementation split across Sky (workbench renderer), Cocoon (extension-host Node sidecar), and Mountain (Rust backend).

Dual-Track Strategy

Track A - Stock-Node: Cocoon loads stock VS Code extHost*.ts sources unchanged. The workbench’s mainThread*.ts runs inside Sky. The ExtHostContext/MainContext RPC glue is provided by Cocoon’s shim alongside stock extHost code. Maximum compatibility from day one for any API the stock implementation handles in-process.
Track B - Rust-native: Mountain owns the backend. Cocoon’s vscode shim sends gRPC to Mountain which does the work natively (filesystem, process, terminal, search, git). Faster and safer than bouncing through Node for I/O-heavy APIs.

The two tracks are not mutually exclusive. Most APIs live on Track A by default, and we promote individual operations to Track B when a measured benefit exists. The Cocoon <Namespace>Route.ts tier router decides per-call.

Legend

Track	Meaning
A	Stock-Node - lift unchanged `extHost*.ts` into Cocoon
B	Rust-native - Mountain owns backend, gRPC from Cocoon
C	Cocoon-bespoke - hand-rolled TS in Land (last resort)
S	Sky-direct - call via `__CEL_SERVICES__.*` workbench accessor

Status symbols:

Working - end-to-end (activation + feature render path confirmed)
Partial - RPC wired but UI render gap, or missing sub-method
Stubbed - registration accepted, no effect
Not attempted
Pure lift - stateless, no RPC, already landed via StockLift.ts

Commands

Operation	Primary	Status
`registerCommand`	A+S	Working
`registerTextEditorCommand`	A	Working
`executeCommand`	A+S	Working
`getCommands`	A	Working

Window - Editors

Operation	Primary	Status
`activeTextEditor`	A	Working
`visibleTextEditors`	A	Working
`showTextDocument`	A	Working
`onDidChangeActiveTextEditor`	A	Working

Window - Surfaces

Operation	Primary	Status
`createStatusBarItem`	S (native)	Working
`setStatusBarMessage`	S	Working
`createTreeView`	A+S	Working
`registerTreeDataProvider`	A+S	Working
`createWebviewPanel`	A	Stubbed
`registerWebviewViewProvider`	A	Stubbed
`registerCustomEditorProvider`	A	Stubbed
`createTerminal`	B	Partial
`onDidOpen/CloseTerminal`	B	Partial
`createOutputChannel`	S	Working
`showInformationMessage` / `showWarningMessage` / `showErrorMessage`	A	Working
`showQuickPick` / `createQuickPick`	A	Partial
`showInputBox`	A	Partial
`showOpenDialog` / `showSaveDialog`	B	Working
`withProgress`	A+S	Partial
`registerFileDecorationProvider`	A	Partial
`registerUriHandler`	A	Partial
`onDidChangeWindowState`	A	Working
`showNotebookDocument`	A	Stubbed

Workspace

Operation	Primary	Status
`workspaceFolders`	A	Working
`onDidChangeWorkspaceFolders`	A	Working
`getWorkspaceFolder`	A+B	Working
`textDocuments`	A	Working
`openTextDocument`	A+B	Working
`onDidOpen/Close/SaveTextDocument`	A	Working
`onWillSaveTextDocument`	A	Partial
`applyEdit`	A+S	Partial
`save` / `saveAs`	A	Gap
`fs.readFile` / `writeFile` / `stat` / `readDirectory` / `createDirectory` / `delete` / `rename` / `copy`	B	Working
`fs.isWritableFileSystem`	A	Working
`registerFileSystemProvider`	A	Partial
`createFileSystemWatcher`	B	Partial
`findFiles`	B	Working
`findTextInFiles`	B	Working
`registerTextDocumentContentProvider`	A	Partial
`getConfiguration` / `onDidChangeConfiguration`	A+B	Working
`registerTaskProvider`	A	Partial

Languages

Operation	Primary	Status
`registerCompletionItemProvider`	A	Partial
`registerHoverProvider`	A	Partial
`registerDefinitionProvider`	A	Partial
`registerReferenceProvider`	A	Partial
`registerDocumentSymbolProvider`	A	Partial
`registerCodeActionsProvider`	A	Partial
`registerCodeLensProvider`	A	Partial
`registerDocumentFormattingEditProvider`	A	Partial
`registerRenameProvider`	A	Partial
`registerInlayHintsProvider`	A	Partial
`registerFoldingRangeProvider`	A	Partial
`registerSemanticTokensProvider`	A	Partial
`registerSignatureHelpProvider`	A	Partial
`setTextDocumentLanguage`	A+S	Working
`setLanguageConfiguration`	A+S	Working
`createDiagnosticCollection`	A+S	Working
`match`	Pure	Working

Debug

Operation	Primary	Status
`registerDebugConfigurationProvider`	A	Partial
`registerDebugAdapterDescriptorFactory`	A	Partial
`registerDebugAdapterTrackerFactory`	A	Partial
`startDebugging`	A+B	Stubbed
`activeDebugSession` / `onDidStart/ChangeSession`	A	Stubbed
`addBreakpoints` / `removeBreakpoints`	A	Stubbed
`activeStackItem`	A	Gap

Tasks

Operation	Primary	Status
`registerTaskProvider`	A	Partial
`fetchTasks`	A	Stubbed
`executeTask`	A+B	Stubbed
`taskExecutions` / `onDidStartTask` / `onDidEndTask`	A	Stubbed

SCM

Operation	Primary	Status
`createSourceControl`	A+S	Partial
`inputBox.value` read/write	A	Partial
`$gitExec` (built-in git ext)	B	Stubbed

Environment

Operation	Primary	Status
`appName` / `appRoot` / `uriScheme` / `language` / `shell` / `machineId` / `sessionId` / `isNewAppInstall`	A	Working
`clipboard.readText` / `writeText`	B	Working
`openExternal`	B	Working
`asExternalUri`	A	Gap
`remoteName` / `remoteAuthority`	A	Working

Extensions

Operation	Primary	Status
`getExtension(id)`	A	Working
`all`	A	Working
`onDidChange`	A	Working

Authentication

Operation	Primary	Status
`registerAuthenticationProvider`	A	Partial
`getSession`	A	Partial
`getAccounts`	A	Partial

Notebooks

Operation	Primary	Status
`createNotebookController`	A	Stubbed
`registerNotebookCellStatusBarItemProvider`	A	Stubbed
`registerNotebookSerializer`	A	Partial

Tests

Operation	Primary	Status
`createTestController`	A	Partial
Run profile / run request	A	Stubbed

Chat / LM

Operation	Primary	Status
`createChatParticipant`	A	Stubbed
`registerLanguageModelChatProvider`	A	Gap
`selectChatModels`	A	Stubbed

Localization

Operation	Primary	Status
`t(message, ...)`	Pure	Working
`bundle` / `uri`	A	Working

Comments

Operation	Primary	Status
`createCommentController`	A	Stubbed

Domain-Grouped Primary Assignment

Rust-native primary (Track B wins)

High I/O, process, or syscall-bound operations where Node adds latency:

File system — workspace.fs.*, scanner reads. Mountain owns File::* via tokio.
Find files / text search — workspace.findFiles / findTextInFiles. Mountain’s globset walk.
Terminal PTY — Mountain-owned via portable-pty.
Git subprocess — Mountain spawns git as a child process.
File watch — createFileSystemWatcher. Mountain notify crate.
Native dialogs / clipboard / openExternal — Tauri covers these.
Process spawn for debug adapters / task exec — upcoming via tokio::process.

Node-stock primary (Track A wins)

State-heavy or coordination-heavy APIs where stock VS Code handles nuance:

Command registry, language features, editor/document/selection, configuration, messages/dialogs/quick-input, progress, secrets/storage/memento, authentication, debug/tasks (stock core + Mountain process spawn), webviews, notebooks, tree views.

Hybrid (per-operation split)

SCM — stock for provider registration, Mountain-native for $gitExec.
Terminal shell integration — shell events via extHost, PTY via Mountain.
FileSystemProvider — Cocoon forwards reads via gRPC to Mountain for disk ops.
Status bar — stock manages entry lifecycle, Sky renders via __CEL_SERVICES__.Statusbar.

Highest-Priority Gaps

vscode.debug.* end-to-end (startDebugging, sessions, breakpoints) — blocks every language debugger.
vscode.tasks.executeTask — blocks Jake / Gulp / Grunt / npm task providers.
vscode.window.createWebviewPanel — blocks GitLens graph panel, Copilot chat, markdown-preview internals.
vscode.scm viewlet route into ISCMService — extensions register but UI stays empty.
Tree-view renderer wiring — landed: extension-registered tree views render via __CEL_SERVICES__.TreeViewByViewId(id).dataProvider.
localGit channel — landed.