diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index a08a922651d..7c034b314c1 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -6042,15 +6042,19 @@ declare module 'vscode' {
 		export function openExternal(target: Uri): Thenable<boolean>;
 
 		/**
-		 * The [authority](#Uri.authority)-component. When `undefined`, extensions are
-		 * executed in the same context (e.g. operating system or machine) in which the UI
-		 * of the editor is executed. If defined, extensions are running in a different
-		 * context, for instance a remote machine.
+		 * Information about running remotely. When `undefined`, extensions are executed in the same
+		 * context (e.g. operating system or machine) in which the UI of the editor is executed.
+		 * If defined, extensions are running in a different context, for instance a remote machine.
 		 *
-		 * *Note* that no assumptions about the actual value should be made as it is defined
-		 * by extensions and not by the editor.
+		 * A remote [uri](#Uri) adheres to this format: `remote_scheme://auth_prefix+auth_rest/path` where
+		 * the `remote_scheme` is defined by the editor, `auth_prefix` and `auth_rest` are defined by extensions,
+		 * and `path` is defined by the user.
+		 *
+		 * Extensions contributing a remote are encouraged to use a stable `auth_prefix`-value,
+		 * e.g `remote_scheme://ssh+23/` and `remote_scheme://ssh+42`. Such prefix is exposed
+		 * in the `prefix`-property of the returned object.
 		 */
-		export const remoteAuthority: string | undefined;
+		export const remoteAuthority: { prefix: string } | undefined;
 	}
 
 	/**
diff --git a/src/vs/workbench/api/node/extHost.api.impl.ts b/src/vs/workbench/api/node/extHost.api.impl.ts
index 272dc9788e3..c46ff996455 100644
--- a/src/vs/workbench/api/node/extHost.api.impl.ts
+++ b/src/vs/workbench/api/node/extHost.api.impl.ts
@@ -236,7 +236,7 @@ export function createApiFactory(
 		};
 
 		// namespace: env
-		const env: typeof vscode.env = Object.freeze({
+		const env: typeof vscode.env = Object.freeze<typeof vscode.env>({
 			get machineId() { return initData.telemetryInfo.machineId; },
 			get sessionId() { return initData.telemetryInfo.sessionId; },
 			get language() { return initData.environment.appLanguage; },
@@ -257,7 +257,21 @@ export function createApiFactory(
 			openExternal(uri: URI) {
 				return extHostWindow.openUri(uri, { allowTunneling: !!initData.remoteAuthority });
 			},
-			get remoteAuthority() { return initData.remoteAuthority || undefined; }
+			get remoteAuthority() {
+				const { remoteAuthority } = initData;
+				if (!remoteAuthority) {
+					return undefined;
+				}
+				const idx = remoteAuthority.indexOf('+');
+				if (idx < 0) {
+					console.warn(`INVALID remote authority: ${remoteAuthority}`);
+					return undefined;
+				}
+				return {
+					prefix: remoteAuthority.substring(0, idx),
+					toString() { return remoteAuthority; } // compatiblity
+				};
+			}
 		});
 
 		// namespace: extensions