diff --git a/extensions/git/src/api.d.ts b/extensions/git/src/api.d.ts
new file mode 100644
index 00000000000..3273c7e4c00
--- /dev/null
+++ b/extensions/git/src/api.d.ts
@@ -0,0 +1,31 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Uri, SourceControlInputBox } from 'vscode';
+
+declare module GitExtension {
+	export interface API {
+
+	}
+
+	// export const availableVersions: string[];
+	// export function getAPI(version: string): API;
+
+	//#region Deprecated API
+	export interface InputBox {
+		value: string;
+	}
+
+	export interface Repository {
+		readonly rootUri: Uri;
+		readonly inputBox: InputBox;
+	}
+	//#endregion
+}
+
+export interface GitExtension {
+	getRepositories(): Promise<GitExtension.Repository[]>;
+	getGitPath(): Promise<string>;
+}
\ No newline at end of file
diff --git a/extensions/git/src/api.impl.ts b/extensions/git/src/api.impl.ts
new file mode 100644
index 00000000000..ff702cf52e8
--- /dev/null
+++ b/extensions/git/src/api.impl.ts
@@ -0,0 +1,42 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+import { Model } from './model';
+import { Repository as ModelRepository } from './repository';
+import { Uri, SourceControlInputBox } from 'vscode';
+import { GitExtension } from './api';
+
+class InputBoxImpl implements GitExtension.InputBox {
+	set value(value: string) { this.inputBox.value = value; }
+	get value(): string { return this.inputBox.value; }
+	constructor(private inputBox: SourceControlInputBox) { }
+}
+
+class RepositoryImpl implements GitExtension.Repository {
+
+	readonly rootUri: Uri;
+	readonly inputBox: GitExtension.InputBox;
+
+	constructor(repository: ModelRepository) {
+		this.rootUri = Uri.file(repository.root);
+		this.inputBox = new InputBoxImpl(repository.inputBox);
+	}
+}
+
+export function createGitExtension(model?: Model): GitExtension {
+	if (!model) {
+		return {
+			getGitPath() { throw new Error('Git model not found'); },
+			getRepositories() { throw new Error('Git model not found'); }
+		};
+	}
+
+	return {
+		async getGitPath() { return model.git.path; },
+		async getRepositories() { return model.repositories.map(repository => new RepositoryImpl(repository)); }
+	};
+}
diff --git a/extensions/git/src/api.ts b/extensions/git/src/api.ts
deleted file mode 100644
index cfce4c9ed8b..00000000000
--- a/extensions/git/src/api.ts
+++ /dev/null
@@ -1,65 +0,0 @@
-/*---------------------------------------------------------------------------------------------
- *  Copyright (c) Microsoft Corporation. All rights reserved.
- *  Licensed under the MIT License. See License.txt in the project root for license information.
- *--------------------------------------------------------------------------------------------*/
-
-'use strict';
-
-import { Model } from './model';
-import { Repository as ModelRepository } from './repository';
-import { Uri, SourceControlInputBox } from 'vscode';
-
-export interface InputBox {
-	value: string;
-}
-
-export class InputBoxImpl implements InputBox {
-	set value(value: string) { this.inputBox.value = value; }
-	get value(): string { return this.inputBox.value; }
-	constructor(private inputBox: SourceControlInputBox) { }
-}
-
-export interface Repository {
-	readonly rootUri: Uri;
-	readonly inputBox: InputBox;
-}
-
-export class RepositoryImpl implements Repository {
-
-	readonly rootUri: Uri;
-	readonly inputBox: InputBox;
-
-	constructor(repository: ModelRepository) {
-		this.rootUri = Uri.file(repository.root);
-		this.inputBox = new InputBoxImpl(repository.inputBox);
-	}
-}
-
-export interface API {
-	getRepositories(): Promise<Repository[]>;
-	getGitPath(): Promise<string>;
-}
-
-export class APIImpl implements API {
-
-	constructor(private model: Model) { }
-
-	async getGitPath(): Promise<string> {
-		return this.model.git.path;
-	}
-
-	async getRepositories(): Promise<Repository[]> {
-		return this.model.repositories.map(repository => new RepositoryImpl(repository));
-	}
-}
-
-export class NoopAPIImpl implements API {
-
-	async getGitPath(): Promise<string> {
-		throw new Error('Git model not found');
-	}
-
-	async getRepositories(): Promise<Repository[]> {
-		throw new Error('Git model not found');
-	}
-}
diff --git a/extensions/git/src/main.ts b/extensions/git/src/main.ts
index 186dd806118..f4833c8985f 100644
--- a/extensions/git/src/main.ts
+++ b/extensions/git/src/main.ts
@@ -7,6 +7,7 @@
 
 import * as nls from 'vscode-nls';
 const localize = nls.loadMessageBundle();
+
 import { ExtensionContext, workspace, window, Disposable, commands, Uri, OutputChannel } from 'vscode';
 import { findGit, Git, IGit } from './git';
 import { Model } from './model';
@@ -16,8 +17,9 @@ import { GitDecorations } from './decorationProvider';
 import { Askpass } from './askpass';
 import { toDisposable, filterEvent, eventToPromise } from './util';
 import TelemetryReporter from 'vscode-extension-telemetry';
-import { API, NoopAPIImpl, APIImpl } from './api';
+import { GitExtension } from './api';
 import { GitProtocolHandler } from './protocolHandler';
+import { createGitExtension } from './api.impl';
 
 const deactivateTasks: { (): Promise<any>; }[] = [];
 
@@ -69,7 +71,7 @@ async function createModel(context: ExtensionContext, outputChannel: OutputChann
 	return model;
 }
 
-export async function activate(context: ExtensionContext): Promise<API> {
+export async function activate(context: ExtensionContext): Promise<GitExtension> {
 	const disposables: Disposable[] = [];
 	context.subscriptions.push(new Disposable(() => Disposable.from(...disposables).dispose()));
 
@@ -92,7 +94,7 @@ export async function activate(context: ExtensionContext): Promise<API> {
 
 	try {
 		const model = await createModel(context, outputChannel, telemetryReporter, disposables);
-		return new APIImpl(model);
+		return createGitExtension(model);
 	} catch (err) {
 		if (!/Git installation not found/.test(err.message || '')) {
 			throw err;
@@ -121,7 +123,7 @@ export async function activate(context: ExtensionContext): Promise<API> {
 			}
 		}
 
-		return new NoopAPIImpl();
+		return createGitExtension();
 	}
 }