Add SSH remote agent host bootstrap

package.json

@@ -123,6 +123,7 @@
     "node-pty": "^1.2.0-beta.12",
     "open": "^10.1.2",
     "playwright-core": "1.59.0-alpha-2026-02-20",
+    "ssh2": "^1.16.0",
     "tas-client": "0.3.1",
     "undici": "^7.24.0",
     "v8-inspect-profiler": "^0.1.1",
@@ -148,6 +149,7 @@
     "@types/node": "^22.18.10",
     "@types/sinon": "^10.0.2",
     "@types/sinon-test": "^2.4.2",
+    "@types/ssh2": "^1.15.4",
     "@types/trusted-types": "^2.0.7",
     "@types/vscode-notebook-renderer": "^1.72.0",
     "@types/wicg-file-system-access": "^2023.10.7",

src/vs/platform/agentHost/common/sshRemoteAgentHost.ts

@@ -0,0 +1,85 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Event } from '../../../base/common/event.js';
+import { IDisposable } from '../../../base/common/lifecycle.js';
+import { createDecorator } from '../../instantiation/common/instantiation.js';
+
+export const ISSHRemoteAgentHostService = createDecorator<ISSHRemoteAgentHostService>('sshRemoteAgentHostService');
+
+export const enum SSHAuthMethod {
+	/** Use the local SSH agent for key-based auth. */
+	Agent = 'agent',
+	/** Authenticate with an explicit private key file. */
+	KeyFile = 'keyFile',
+	/** Authenticate with a password. */
+	Password = 'password',
+}
+
+export interface ISSHAgentHostConfig {
+	/** Remote hostname or IP. */
+	readonly host: string;
+	/** SSH port (default 22). */
+	readonly port?: number;
+	/** Username on the remote machine. */
+	readonly username: string;
+	/** Authentication method. */
+	readonly authMethod: SSHAuthMethod;
+	/** Path to the private key file (when {@link authMethod} is KeyFile). */
+	readonly privateKeyPath?: string;
+	/** Password string (when {@link authMethod} is Password). */
+	readonly password?: string;
+	/** Display name for this connection. */
+	readonly name: string;
+}
+
+export interface ISSHAgentHostConnection extends IDisposable {
+	/** The SSH config used to establish this connection. */
+	readonly config: ISSHAgentHostConfig;
+	/** The local forwarded address (e.g. `127.0.0.1:54321`) registered with IRemoteAgentHostService. */
+	readonly localAddress: string;
+	/** The display name. */
+	readonly name: string;
+	/** Fires when this SSH connection is closed or lost. */
+	readonly onDidClose: Event<void>;
+}
+
+/**
+ * Manages SSH connections that bootstrap a remote agent host process.
+ *
+ * Each connection SSHs into a remote machine, ensures the VS Code CLI
+ * is installed, starts `code agent-host`, and creates a local TCP
+ * port forward so the sessions app can connect via its standard
+ * WebSocket transport.
+ */
+export interface ISSHRemoteAgentHostService {
+	readonly _serviceBrand: undefined;
+
+	/** Fires when the set of active SSH connections changes. */
+	readonly onDidChangeConnections: Event<void>;
+
+	/** Currently active SSH-bootstrapped connections. */
+	readonly connections: readonly ISSHAgentHostConnection[];
+
+	/**
+	 * Bootstrap a remote agent host over SSH.
+	 *
+	 * 1. Opens an SSH connection to the remote host
+	 * 2. Downloads and installs the VS Code CLI if needed
+	 * 3. Starts `code agent-host`
+	 * 4. Forwards the remote agent host port to a local port
+	 * 5. Registers the local address with {@link IRemoteAgentHostService}
+	 *
+	 * Resolves with the connection handle once the agent host is reachable.
+	 */
+	connect(config: ISSHAgentHostConfig): Promise<ISSHAgentHostConnection>;
+
+	/**
+	 * Disconnect an SSH-bootstrapped connection by host address.
+	 * Tears down the SSH tunnel, stops the remote agent host, and
+	 * removes the entry from {@link IRemoteAgentHostService}.
+	 */
+	disconnect(host: string): Promise<void>;
+}

src/vs/platform/agentHost/electron-browser/sshRemoteAgentHostService.ts

@@ -0,0 +1,10 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { InstantiationType, registerSingleton } from '../../instantiation/common/extensions.js';
+import { ISSHRemoteAgentHostService } from '../common/sshRemoteAgentHost.js';
+import { SSHRemoteAgentHostService } from './sshRemoteAgentHostServiceImpl.js';
+
+registerSingleton(ISSHRemoteAgentHostService, SSHRemoteAgentHostService, InstantiationType.Delayed);