diff --git a/client/vscode/src/extension.js b/client/vscode/src/extension.js
index 27a6217..176e42b 100644
--- a/client/vscode/src/extension.js
+++ b/client/vscode/src/extension.js
@@ -2,17 +2,108 @@ const vscode = require("vscode");
 const codemp = require("./codemp.node");
 
 var CLIENT = null
+var CONTROLLER
+var OP_CACHE = new Set()
 
 async function activate(context) {
-	// This must match the command property in the package.json
-	const commandID = "codemp.connect";
-	let disposable = vscode.commands.registerCommand(commandID, connect);
-	context.subscriptions.push(disposable);
+	context.subscriptions.push(
+		vscode.commands.registerCommand("codemp.connect", connect),
+		vscode.commands.registerCommand("codemp.share", share),
+		vscode.commands.registerCommand("codemp.join", join),
+	)
 }
 
 async function connect() {
-	CLIENT = await codemp.connect("http://fantabos.co:50051")
-	vscode.window.showInformationMessage("Connected to CodeMP!");
+	let host = await vscode.window.showInputBox({prompt: "server host (default to http://fantabos.co:50051)"})
+	if (host === undefined) return  // user cancelled with ESC
+	if (host.length == 0) host = "http://fantabos.co:50051"
+	CLIENT = await codemp.connect(host)
+	vscode.window.showInformationMessage(`Connected to codemp @[${host}]`);
+}
+
+async function share() {
+	if (CLIENT === null) {
+		vscode.window.showErrorMessage("No connected client");
+	}
+
+	let path = await vscode.window.showInputBox({prompt: "buffer uri (default to file path)"})
+	if (path === undefined) return  // user cancelled with ESC
+	if (path.length == 0) path = doc.uri.toString()
+
+	let doc = vscode.window.activeTextEditor.document;
+
+	try {
+		if (!await CLIENT.create(path, doc.getText())) {
+			vscode.window.showErrorMessage("Could not share buffer");
+		}
+
+		await _attach(path)
+
+		vscode.window.showInformationMessage(`Shared document on buffer "${path}"`);
+	} catch (err) {
+		vscode.window.showErrorMessage("Error sharing: " + err)
+	}
+}
+
+async function join() {
+	if (CLIENT === null) {
+		vscode.window.showErrorMessage("No connected client");
+	}
+
+	let path = await vscode.window.showInputBox({prompt: "buffer uri"})
+
+	try {
+		let controller = await _attach(path)
+
+		vscode.window.showInformationMessage(`Joined buffer "${path}"`);
+
+		let editor = vscode.window.activeTextEditor
+
+		let range = new vscode.Range(
+			editor.document.positionAt(0),
+			editor.document.positionAt(editor.document.getText().length)
+		)
+		let content = controller.content()
+		OP_CACHE.add((range, content))
+		editor.edit(editBuilder => editBuilder.replace(range, content))
+	} catch (err) {
+		vscode.window.showErrorMessage("error joining " + err)
+	}
+}
+
+async function _attach(path) {
+	let doc = vscode.window.activeTextEditor.document;
+	CONTROLLER = await CLIENT.attach(path)
+	vscode.workspace.onDidChangeTextDocument(async (e) => {
+		if (e.document != doc) return
+		for (let change of e.contentChanges) {
+			if (OP_CACHE.has((change.range, change.text))) {
+				OP_CACHE.delete((change.range, change.text))
+				continue
+			}
+			try {
+				await CONTROLLER.apply(change.rangeOffset, change.text, change.rangeOffset + change.rangeLength)
+			} catch (err) {
+				vscode.window.showErrorMessage("failed sending change: " + err)
+			}
+		}
+	})
+	let editor = vscode.window.activeTextEditor
+	CONTROLLER.set_callback((start, end) => {
+		// TODO only change affected document range
+		let content = CONTROLLER.content()
+		let range = new vscode.Range(
+			editor.document.positionAt(0),
+			editor.document.positionAt(editor.document.getText().length)
+		)
+		try {
+			OP_CACHE.add((range, content))
+			editor.edit(editBuilder => editBuilder.replace(range, content))
+		} catch (err) {
+			vscode.window.showErrorMessage("could not set buffer: " + err)
+		}
+	})
+	return CONTROLLER
 }
 
 module.exports = {