diff --git a/etc/api/BUILD b/etc/api/BUILD
index fb66f90a6a..3e8f83d9be 100644
--- a/etc/api/BUILD
+++ b/etc/api/BUILD
@@ -30,6 +30,8 @@ load("@angular//tools/ts-api-guardian:index.bzl", "ts_api_guardian_test")
     # We don't want to analyse these exports nor add them to the golden files
     # in most cases it's because Ts API Guardian doesn't support Symbol Aliases.
     strip_export_pattern = [
+        # @angular-devkit/architect
+        "^BuilderProgressState$",
         # @angular-devkit/schematics
         "^workflow$",
         "^formats$",
diff --git a/etc/api/angular_devkit/architect/src/_golden-api.d.ts b/etc/api/angular_devkit/architect/src/_golden-api.d.ts
deleted file mode 100644
index 5b09b41068..0000000000
--- a/etc/api/angular_devkit/architect/src/_golden-api.d.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-export declare class Architect {
-    constructor(_host: ArchitectHost, _registry?: json.schema.SchemaRegistry, additionalJobRegistry?: experimental.jobs.Registry);
-    has(name: experimental.jobs.JobName): Observable<boolean>;
-    scheduleBuilder(name: string, options: json.JsonObject, scheduleOptions?: ScheduleOptions): Promise<BuilderRun>;
-    scheduleTarget(target: Target, overrides?: json.JsonObject, scheduleOptions?: ScheduleOptions): Promise<BuilderRun>;
-}
-
-export declare function createBuilder<OptT extends json.JsonObject, OutT extends BuilderOutput = BuilderOutput>(fn: BuilderHandlerFn<OptT>): Builder<OptT>;
-
-export interface ScheduleOptions {
-    analytics?: analytics.Analytics;
-    logger?: logging.Logger;
-}
diff --git a/etc/api/angular_devkit/architect/src/index.d.ts b/etc/api/angular_devkit/architect/src/index.d.ts
new file mode 100644
index 0000000000..db5ff0a7f9
--- /dev/null
+++ b/etc/api/angular_devkit/architect/src/index.d.ts
@@ -0,0 +1,89 @@
+export declare class Architect {
+    constructor(_host: ArchitectHost, _registry?: json.schema.SchemaRegistry, additionalJobRegistry?: experimental.jobs.Registry);
+    has(name: experimental.jobs.JobName): Observable<boolean>;
+    scheduleBuilder(name: string, options: json.JsonObject, scheduleOptions?: ScheduleOptions): Promise<BuilderRun>;
+    scheduleTarget(target: Target, overrides?: json.JsonObject, scheduleOptions?: ScheduleOptions): Promise<BuilderRun>;
+}
+
+export interface BuilderContext {
+    readonly analytics: analytics.Analytics;
+    builder: BuilderInfo;
+    currentDirectory: string;
+    id: number;
+    logger: logging.LoggerApi;
+    target?: Target;
+    workspaceRoot: string;
+    addTeardown(teardown: () => (Promise<void> | void)): void;
+    getBuilderNameForTarget(target: Target): Promise<string>;
+    getTargetOptions(target: Target): Promise<json.JsonObject>;
+    reportProgress(current: number, total?: number, status?: string): void;
+    reportRunning(): void;
+    reportStatus(status: string): void;
+    scheduleBuilder(builderName: string, options?: json.JsonObject, scheduleOptions?: ScheduleOptions): Promise<BuilderRun>;
+    scheduleTarget(target: Target, overrides?: json.JsonObject, scheduleOptions?: ScheduleOptions): Promise<BuilderRun>;
+    validateOptions<T extends json.JsonObject = json.JsonObject>(options: json.JsonObject, builderName: string): Promise<T>;
+}
+
+export interface BuilderHandlerFn<A extends json.JsonObject> {
+    (input: A, context: BuilderContext): BuilderOutputLike;
+}
+
+export declare type BuilderInfo = json.JsonObject & {
+    builderName: string;
+    description: string;
+    optionSchema: json.schema.JsonSchema;
+};
+
+export declare type BuilderInput = json.JsonObject & RealBuilderInput;
+
+export declare type BuilderOutput = json.JsonObject & RealBuilderOutput;
+
+export declare type BuilderOutputLike = Observable<BuilderOutput> | Promise<BuilderOutput> | BuilderOutput;
+
+export declare type BuilderProgress = json.JsonObject & RealBuilderProgress & TypedBuilderProgress;
+
+export declare type BuilderProgressReport = BuilderProgress & ({
+    target?: Target;
+    builder: BuilderInfo;
+});
+
+export declare type BuilderRegistry = experimental.jobs.Registry<json.JsonObject, BuilderInput, BuilderOutput>;
+
+export interface BuilderRun {
+    id: number;
+    info: BuilderInfo;
+    output: Observable<BuilderOutput>;
+    progress: Observable<BuilderProgressReport>;
+    result: Promise<BuilderOutput>;
+    stop(): Promise<void>;
+}
+
+export declare function createBuilder<OptT extends json.JsonObject, OutT extends BuilderOutput = BuilderOutput>(fn: BuilderHandlerFn<OptT>): Builder<OptT>;
+
+export interface ScheduleOptions {
+    analytics?: analytics.Analytics;
+    logger?: logging.Logger;
+}
+
+export declare function scheduleTargetAndForget(context: BuilderContext, target: Target, overrides?: json.JsonObject, scheduleOptions?: ScheduleOptions): Observable<BuilderOutput>;
+
+export declare type Target = json.JsonObject & RealTarget;
+
+export declare function targetFromTargetString(str: string): Target;
+
+export declare function targetStringFromTarget({ project, target, configuration }: Target): string;
+
+export declare type TypedBuilderProgress = ({
+    state: BuilderProgressState.Stopped;
+} | {
+    state: BuilderProgressState.Error;
+    error: json.JsonValue;
+} | {
+    state: BuilderProgressState.Waiting;
+    status?: string;
+} | {
+    state: BuilderProgressState.Running;
+    status?: string;
+    current: number;
+    total?: number;
+});
diff --git a/packages/angular_devkit/architect/src/_golden-api.d.ts b/packages/angular_devkit/architect/src/_golden-api.d.ts
deleted file mode 100644
index 759ed24866..0000000000
--- a/packages/angular_devkit/architect/src/_golden-api.d.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-/**
- * @license
- * Copyright Google Inc. All Rights Reserved.
- *
- * Use of this source code is governed by an MIT-style license that can be
- * found in the LICENSE file at https://angular.io/license
- */
-export { Architect, ScheduleOptions } from './architect';
-export { createBuilder } from './create-builder';