diff --git a/siesta/siesta-tests.ts b/siesta/siesta-tests.ts
index 2439ff84f..213990aa7 100644
--- a/siesta/siesta-tests.ts
+++ b/siesta/siesta-tests.ts
@@ -7,4 +7,22 @@ startTest(function (t: Siesta.Test) {
 });
 
 describe(function (t: Siesta.Test) {
+});
+
+var Harness = Siesta.Harness.Browser;
+
+Harness.start(<Siesta.Harness.ITestGroupDescriptor>{
+    group: 'MyGroup',
+    items: [
+        'test-script01.js',
+        'test-script02.js',
+        <Siesta.Harness.ITestUrlDescriptor>{
+            url: 'http://somesite.com/test-script03.js',
+            preload: [<Siesta.Harness.IPreloadUrlDescriptor>{
+                type: 'css',
+                url: 'http://somesite.com/test-script03.css'
+            }]
+        }
+    ],
+    option1: true
 });
\ No newline at end of file
diff --git a/siesta/siesta.d.ts b/siesta/siesta.d.ts
index 2046f7089..e987f3ce6 100644
--- a/siesta/siesta.d.ts
+++ b/siesta/siesta.d.ts
@@ -5,28 +5,170 @@ declare var startTest: typeof StartTest;
 declare var describe: typeof StartTest;
 
 declare module Siesta {
-    export class Harness {
+
+    //#region Harness
+
+    class Harness {
+        alsoPreload: any[];
+
+        autoCheckGlobals: boolean;
+
+        cachePreload: boolean;
+
+        defaultTimeout: boolean;
+
+        disableColoring: boolean;
+
+        expectedGlobals: string[];
+
+        isReadyTimeout: number;
+
+        keepNLastResults: number;
+
+        keepResults: boolean;
+
+        listenters: {
+            [key: string]: (event: Event, ...args: any[]) => void;
+        }
+
+        maxThreads: number;
+
+        needDone: boolean;
+
+        overrideSetTimeout: boolean;
+
+        pauseBetweenTests: number;
+
+        preload: any[];
+
+        runCore: string;
+
+        subTestTimeout: number;
+
+        testClass: Siesta.Test;
+
+        title: string;
+
+        transparentEx: boolean;
+
+        waitForTimeout: number;
+
+        configure(config: any): void;
+
+        start(...descriptors: any[]): void;
     }
 
-    export module Harness {
-        export class Browser extends Harness {
+    module Harness {
+        interface ITestGroupDescriptor {
+            group: string;
+
+            items: any[];
         }
 
-        export module Browser {
-            export class ExtJS extends Browser implements ExtJSCore {
-            }
-
-            export class ExtJSCore {
-            }
-
-            export class SenchaTouch extends Browser implements ExtJSCore {
-            }
+        interface ITestUrlDescriptor {
+            url: string;
         }
 
-        export class NodeJS implements Harness {
+        interface IPreloadUrlDescriptor {
+            type: string;
+
+            url: string;
         }
+
+        interface IPreloadContentDescriptor {
+            type: string;
+
+            content: string;
+        }
+
+        interface IPreloadTextDescriptor {
+            text: string;
+        }
+
+        interface IBrowser extends Harness {
+            autoRun: boolean;
+
+            autoScrollElementsIntoView: boolean;
+
+            breakOnFail: boolean;
+
+            coverageUnit: string;
+
+            disableCaching: boolean;
+
+            enableCodeCoverage: boolean;
+
+            excludeCoverageUnits: RegExp;
+
+            hostPageUrl: string;
+
+            includeCoverageUnits: RegExp;
+
+            maintainViewportSize: boolean;
+
+            runCore: string;
+
+            separateContext: boolean;
+
+            simulateEventsWith: string;
+
+            speedRun: boolean;
+
+            testClass: Function;
+
+            useStrictMode: boolean;
+
+            viewDOM: boolean;
+
+            viewportHeight: number;
+
+            viewportWidth: number;
+        }
+
+        interface IBrowserExtJSCore {
+            coverageUnit: string;
+
+            excludeCoverageUnits: RegExp;
+
+            installLoaderInstrumentationHook: boolean;
+        }
+
+        interface IBrowserExtJS extends IBrowser, IBrowserExtJSCore {
+            allowExtVersionChange: boolean;
+
+            loaderPath: any;
+
+            waitForAppReady;
+
+            waitForExtReady;
+        }
+
+        interface IBrowserSenchaTouch extends IBrowser, IBrowserExtJSCore {
+            loaderPath: any;
+
+            performSetup: boolean;
+
+            runCore: string;
+
+            transparentEx: boolean
+        }
+
+        interface IBrowserSingleton extends IBrowser {
+            ExtJS: IBrowserExtJS;
+
+            SenchaTouch: IBrowserSenchaTouch;
+        }
+
+        interface IHarnessNodeJS extends Harness {
+        }
+
+        var Browser: IBrowserSingleton;
+
+        var NodeJS: IHarnessNodeJS;
     }
 
+    //#endregion
+
     export class Test implements Test.BDD, Test.Date, Test.Function, Test.More {
     }