diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index 500c27d7d6c..46e761bc5ff 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -505,6 +505,24 @@ declare namespace vscode {
 		isReversed: boolean;
 	}
 
+	/**
+	 * Represents sources that can cause [selection change events](#window.onDidChangeTextEditorSelection).
+	*/
+	export enum TextEditorSelectionChangeKind {
+		/**
+		 * Selection changed due to typing in the editor.
+		 */
+		Keyboard = 1,
+		/**
+		 * Selection change due to clicking in the editor.
+		 */
+		Mouse = 2,
+		/**
+		 * Selection changed because a command ran.
+		 */
+		Command = 3
+	}
+
 	/**
 	 * Represents an event describing the change in a [text editor's selections](#TextEditor.selections).
 	 */
@@ -513,6 +531,11 @@ declare namespace vscode {
 		 * The [text editor](#TextEditor) for which the selections have changed.
 		 */
 		textEditor: TextEditor;
+		/**
+		 * The [change kind](#TextEditorSelectionChangeKind) which has triggered this
+		 * event. Can be `undefined`.
+		 */
+		kind: TextEditorSelectionChangeKind;
 		/**
 		 * The new value for the [text editor's selections](#TextEditor.selections).
 		 */
diff --git a/src/vs/workbench/api/node/extHostEditors.ts b/src/vs/workbench/api/node/extHostEditors.ts
index f15a38174b8..4e01b6ebd03 100644
--- a/src/vs/workbench/api/node/extHostEditors.ts
+++ b/src/vs/workbench/api/node/extHostEditors.ts
@@ -11,7 +11,7 @@ import Event, {Emitter} from 'vs/base/common/event';
 import {TPromise} from 'vs/base/common/winjs.base';
 import {IThreadService} from 'vs/workbench/services/thread/common/threadService';
 import {ExtHostDocuments, ExtHostDocumentData} from 'vs/workbench/api/node/extHostDocuments';
-import {Selection, Range, Position, EditorOptions, EndOfLine, TextEditorRevealType} from './extHostTypes';
+import {Selection, Range, Position, EditorOptions, EndOfLine, TextEditorRevealType, TextEditorSelectionChangeKind} from './extHostTypes';
 import {ISingleEditOperation} from 'vs/editor/common/editorCommon';
 import {IResolvedTextEditorConfiguration, ISelectionChangeEvent} from 'vs/workbench/api/node/mainThreadEditorsTracker';
 import * as TypeConverters from './extHostTypeConverters';
@@ -103,12 +103,14 @@ export class ExtHostEditors extends ExtHostEditorsShape {
 	}
 
 	$acceptSelectionsChanged(id: string, event: ISelectionChangeEvent): void {
-		let selections = event.selections.map(TypeConverters.toSelection);
-		let editor = this._editors[id];
-		editor._acceptSelections(selections);
+		const kind = TextEditorSelectionChangeKind.fromValue(event.source);
+		const selections = event.selections.map(TypeConverters.toSelection);
+		const textEditor = this._editors[id];
+		textEditor._acceptSelections(selections);
 		this._onDidChangeTextEditorSelection.fire({
-			textEditor: editor,
-			selections: selections
+			textEditor,
+			selections,
+			kind
 		});
 	}
 
diff --git a/src/vs/workbench/api/node/extHostTypes.ts b/src/vs/workbench/api/node/extHostTypes.ts
index b1a291b7ae4..af533a978b8 100644
--- a/src/vs/workbench/api/node/extHostTypes.ts
+++ b/src/vs/workbench/api/node/extHostTypes.ts
@@ -829,6 +829,22 @@ export enum TextEditorRevealType {
 	InCenterIfOutsideViewport = 2
 }
 
+export enum TextEditorSelectionChangeKind {
+	Keyboard = 1,
+	Mouse = 2,
+	Command = 3
+}
+
+export namespace TextEditorSelectionChangeKind {
+	export function fromValue(s: string) {
+		switch (s) {
+			case 'keyboard': return TextEditorSelectionChangeKind.Keyboard;
+			case 'mouse': return TextEditorSelectionChangeKind.Mouse;
+			case 'api': return TextEditorSelectionChangeKind.Command;
+		}
+	}
+}
+
 export class DocumentLink {
 
 	range: Range;