diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/env.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/env.test.ts
index 4189615c09ebf1cda435521d39785777baacb59e..c927c15c3445fccc0d99a4a82103d532d7c4eb7a 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/env.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/env.test.ts
@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as assert from 'assert';
-import { env, extensions, ExtensionKind, UIKind } from 'vscode';
+import { env, extensions, ExtensionKind, UIKind, Uri } from 'vscode';
 
 suite('env-namespace', () => {
 
@@ -45,8 +45,29 @@ suite('env-namespace', () => {
 		}
 	});
 
-	test('env.uiKind', function () {
+	test('env.uiKind', async function () {
+		const uri = Uri.parse(`${env.uriScheme}:://vscode.vscode-api-tests/path?key=value&other=false`);
+		const result = await env.asExternalUri(uri);
+
 		const kind = env.uiKind;
-		assert.equal(kind, UIKind.Desktop);
+		if (result.scheme === 'http' || result.scheme === 'https') {
+			assert.equal(kind, UIKind.Web);
+		} else {
+			assert.equal(kind, UIKind.Desktop);
+		}
+	});
+
+	test('env.asExternalUri - with env.uriScheme', async function () {
+		const uri = Uri.parse(`${env.uriScheme}:://vscode.vscode-api-tests/path?key=value&other=false`);
+		const result = await env.asExternalUri(uri);
+		assert.ok(result);
+
+		if (env.uiKind === UIKind.Desktop) {
+			assert.equal(uri.scheme, result.scheme);
+			assert.equal(uri.authority, result.authority);
+			assert.equal(uri.path, result.path);
+		} else {
+			assert.ok(result.scheme === 'http' || result.scheme === 'https');
+		}
 	});
 });
diff --git a/src/vs/platform/product/common/product.ts b/src/vs/platform/product/common/product.ts
index 2de51e8d32488d0ea77d3e65e69f9b02c5c9c74c..6f76dd1680f430d441c7f680f95c628cfd5fa71d 100644
--- a/src/vs/platform/product/common/product.ts
+++ b/src/vs/platform/product/common/product.ts
@@ -23,7 +23,8 @@ if (isWeb) {
 		assign(product, {
 			version: '1.39.0-dev',
 			nameLong: 'Visual Studio Code Web Dev',
-			nameShort: 'VSCode Web Dev'
+			nameShort: 'VSCode Web Dev',
+			urlProtocol: 'code-oss'
 		});
 	}
 }
diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index 908e242693e696f77afff7f540060725871a4931..ec9cc035c5067db46f9f76a3a09d2b7ac74a49f8 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -6433,22 +6433,51 @@ declare module 'vscode' {
 		export function openExternal(target: Uri): Thenable<boolean>;
 
 		/**
+		 * Resolves a uri to form that is accessible externally. Currently only supports `https:`, `http:` and
+		 * `vscode.env.uriScheme` uris.
+		 *
+		 * #### `http:` or `https:` scheme
+		 *
 		 * Resolves an *external* uri, such as a `http:` or `https:` link, from where the extension is running to a
 		 * uri to the same resource on the client machine.
 		 *
-		 * This is a no-op if the extension is running on the client machine. Currently only supports
-		 * `https:` and `http:` uris.
+		 * This is a no-op if the extension is running on the client machine.
 		 *
 		 * If the extension is running remotely, this function automatically establishes a port forwarding tunnel
 		 * from the local machine to `target` on the remote and returns a local uri to the tunnel. The lifetime of
 		 * the port fowarding tunnel is managed by VS Code and the tunnel can be closed by the user.
 		 *
-		 * Extensions should not cache the result of `asExternalUri` as the resolved uri may become invalid due to
-		 * a system or user action — for example, in remote cases, a user may close a port forwardng tunnel
-		 * that was opened by `asExternalUri`.
+		 * *Note* that uris passed through `openExternal` are automatically resolved and you should not call `asExternalUri` on them.
+		 *
+		 * #### `vscode.env.uriScheme`
+		 *
+		 * Creates a uri that - if opened in a browser (e.g. via `openExternal`) - will result in a registered [UriHandler](#UriHandler)
+		 * to trigger.
+		 *
+		 * Extensions should not make any assumptions about the resulting uri and should not alter it in anyway.
+		 * Rather, extensions can e.g. use this uri in an authentication flow, by adding the uri as callback query
+		 * argument to the server to authenticate to.
+		 *
+		 * *Note* that if the server decides to add additional query parameters to the uri (e.g. a token or secret), it
+		 * will appear in the uri that is passed to the [UriHandler](#UriHandler).
+		 *
+		 * **Example** of an authentication flow:
+		 * ```typescript
+		 * vscode.window.registerUriHandler({
+		 *   handleUri(uri: vscode.Uri): vscode.ProviderResult<void> {
+		 *     if (uri.path === '/did-authenticate') {
+		 *       console.log(uri.toString());
+		 *     }
+		 *   }
+		 * });
+		 *
+		 * const callableUri = await vscode.env.asExternalUri(vscode.Uri.parse(`${env.uriScheme}:://my.extension/did-authenticate`));
+		 * await vscode.env.openExternal(callableUri);
+		 * ```
 		 *
-		 * *Note* that uris passed through `openExternal` are automatically resolved and you should not call `asExternalUri`
-		 * on them.
+		 * *Note* that extensions should not cache the result of `asExternalUri` as the resolved uri may become invalid due to
+		 * a system or user action — for example, in remote cases, a user may close a port forwarding tunnel that was opened by
+		 * `asExternalUri`.
 		 *
 		 * @return A uri that can be used on the client machine.
 		 */
diff --git a/src/vs/vscode.proposed.d.ts b/src/vs/vscode.proposed.d.ts
index 61705756a25ef3bf6547ef3bfb9677caa899e31b..22067687355fd0902d151ca14b65cd98345b3121 100644
--- a/src/vs/vscode.proposed.d.ts
+++ b/src/vs/vscode.proposed.d.ts
@@ -855,33 +855,7 @@ declare module 'vscode' {
 	export namespace env {
 
 		/**
-		 * Creates a Uri that - if opened in a browser - will result in a
-		 * registered [UriHandler](#UriHandler) to fire. The handler's
-		 * Uri will be configured with the path, query and fragment of
-		 * [AppUriOptions](#AppUriOptions) if provided, otherwise it will be empty.
-		 *
-		 * Extensions should not make any assumptions about the resulting
-		 * Uri and should not alter it in anyway. Rather, extensions can e.g.
-		 * use this Uri in an authentication flow, by adding the Uri as
-		 * callback query argument to the server to authenticate to.
-		 *
-		 * Note: If the server decides to add additional query parameters to the Uri
-		 * (e.g. a token or secret), it will appear in the Uri that is passed
-		 * to the [UriHandler](#UriHandler).
-		 *
-		 * **Example** of an authentication flow:
-		 * ```typescript
-		 * vscode.window.registerUriHandler({
-		 *   handleUri(uri: vscode.Uri): vscode.ProviderResult<void> {
-		 *     if (uri.path === '/did-authenticate') {
-		 *       console.log(uri.toString());
-		 *     }
-		 *   }
-		 * });
-		 *
-		 * const callableUri = await vscode.env.createAppUri({ payload: { path: '/did-authenticate' } });
-		 * await vscode.env.openExternal(callableUri);
-		 * ```
+		 * @deprecated use `vscode.env.asExternalUri` instead.
 		 */
 		export function createAppUri(options?: AppUriOptions): Thenable<Uri>;
 	}
diff --git a/src/vs/workbench/api/browser/mainThreadUrls.ts b/src/vs/workbench/api/browser/mainThreadUrls.ts
index a89f291d6c25266ac866c9a4abdfde76b48689e0..beda98076af2682a2fe6ad8bbc6df7589cd28b5d 100644
--- a/src/vs/workbench/api/browser/mainThreadUrls.ts
+++ b/src/vs/workbench/api/browser/mainThreadUrls.ts
@@ -68,7 +68,11 @@ export class MainThreadUrls implements MainThreadUrlsShape {
 		return Promise.resolve(undefined);
 	}
 
-	async $createAppUri(extensionId: ExtensionIdentifier, options?: { payload?: Partial<UriComponents> }): Promise<URI> {
+	async $createAppUri(uri: UriComponents): Promise<URI> {
+		return this.urlService.create(uri);
+	}
+
+	async $proposedCreateAppUri(extensionId: ExtensionIdentifier, options?: { payload?: Partial<UriComponents> }): Promise<URI> {
 		const payload: Partial<UriComponents> = options && options.payload ? options.payload : Object.create(null);
 
 		// we define the authority to be the extension ID to ensure
diff --git a/src/vs/workbench/api/common/extHost.api.impl.ts b/src/vs/workbench/api/common/extHost.api.impl.ts
index 11968b623782f8fa043d5b22d11b108b9a78dfd3..5b5a76c6fc0fc0f6d47ae9248572b767e7d90d6a 100644
--- a/src/vs/workbench/api/common/extHost.api.impl.ts
+++ b/src/vs/workbench/api/common/extHost.api.impl.ts
@@ -228,7 +228,7 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 			get uriScheme() { return initData.environment.appUriScheme; },
 			createAppUri(options?) {
 				checkProposedApiEnabled(extension);
-				return extHostUrls.createAppUri(extension.identifier, options);
+				return extHostUrls.proposedCreateAppUri(extension.identifier, options);
 			},
 			get logLevel() {
 				checkProposedApiEnabled(extension);
@@ -248,6 +248,10 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 				return extHostWindow.openUri(uri, { allowTunneling: !!initData.remote.isRemote });
 			},
 			asExternalUri(uri: URI) {
+				if (uri.scheme === initData.environment.appUriScheme) {
+					return extHostUrls.createAppUri(uri);
+				}
+
 				return extHostWindow.asExternalUri(uri, { allowTunneling: !!initData.remote.isRemote });
 			},
 			get remoteName() {
diff --git a/src/vs/workbench/api/common/extHost.protocol.ts b/src/vs/workbench/api/common/extHost.protocol.ts
index b8f4e05cc2daf6bbd33a00d107687fe77c7751fe..acb3246bef7ca1e66736da8b6a1d67f91ae6b8ff 100644
--- a/src/vs/workbench/api/common/extHost.protocol.ts
+++ b/src/vs/workbench/api/common/extHost.protocol.ts
@@ -594,7 +594,8 @@ export interface ExtHostWebviewsShape {
 export interface MainThreadUrlsShape extends IDisposable {
 	$registerUriHandler(handle: number, extensionId: ExtensionIdentifier): Promise<void>;
 	$unregisterUriHandler(handle: number): Promise<void>;
-	$createAppUri(extensionId: ExtensionIdentifier, options?: { payload?: Partial<UriComponents> }): Promise<UriComponents>;
+	$createAppUri(uri: UriComponents): Promise<UriComponents>;
+	$proposedCreateAppUri(extensionId: ExtensionIdentifier, options?: { payload?: Partial<UriComponents> }): Promise<UriComponents>;
 }
 
 export interface ExtHostUrlsShape {
diff --git a/src/vs/workbench/api/common/extHostUrls.ts b/src/vs/workbench/api/common/extHostUrls.ts
index 6b6f8081ae58f15f5da1956aa85bd467e24cf9aa..0a4480a63e84dfe3c31d26c876ad446b8a8d2ded 100644
--- a/src/vs/workbench/api/common/extHostUrls.ts
+++ b/src/vs/workbench/api/common/extHostUrls.ts
@@ -56,7 +56,11 @@ export class ExtHostUrls implements ExtHostUrlsShape {
 		return Promise.resolve(undefined);
 	}
 
-	async createAppUri(extensionId: ExtensionIdentifier, options?: vscode.AppUriOptions): Promise<vscode.Uri> {
-		return URI.revive(await this._proxy.$createAppUri(extensionId, options));
+	async createAppUri(uri: URI): Promise<vscode.Uri> {
+		return URI.revive(await this._proxy.$createAppUri(uri));
+	}
+
+	async proposedCreateAppUri(extensionId: ExtensionIdentifier, options?: vscode.AppUriOptions): Promise<vscode.Uri> {
+		return URI.revive(await this._proxy.$proposedCreateAppUri(extensionId, options));
 	}
 }
diff --git a/src/vs/workbench/browser/web.main.ts b/src/vs/workbench/browser/web.main.ts
index 26ccbe6f9ea5abd39950ad5149834549cb003752..665523c0bf5d8b1836129e3e52272d522a36be79 100644
--- a/src/vs/workbench/browser/web.main.ts
+++ b/src/vs/workbench/browser/web.main.ts
@@ -162,10 +162,7 @@ class BrowserMain extends Disposable {
 		// Product
 		const productService = {
 			_serviceBrand: undefined,
-			...{
-				...product,				// dev or built time config
-				...{ urlProtocol: '' }	// web related overrides from us
-			}
+			...product
 		};
 		serviceCollection.set(IProductService, productService);