diff --git a/github-electron/github-electron-main-tests.ts b/github-electron/github-electron-main-tests.ts
index 545c60c68..7b0dc800a 100644
--- a/github-electron/github-electron-main-tests.ts
+++ b/github-electron/github-electron-main-tests.ts
@@ -18,6 +18,7 @@ import {
 	nativeImage,
 	screen,
 	shell,
+	session,
 	hideInternalModules
 } from 'electron';
 
@@ -675,3 +676,69 @@ shell.openExternal('https://github.com', {
 });
 
 shell.beep();
+
+// session
+// https://github.com/atom/electron/blob/master/docs/api/session.md
+
+session.defaultSession.on('will-download', (event, item, webContents) => {
+	event.preventDefault();
+	require('request')(item.getURL(), (data: any) => {
+		require('fs').writeFileSync('/somewhere', data);
+	});
+});
+
+// Query all cookies.
+session.defaultSession.cookies.get({}, (error, cookies) => {
+	console.log(cookies);
+});
+
+// Query all cookies associated with a specific url.
+session.defaultSession.cookies.get({ url : "http://www.github.com" }, (error, cookies) => {
+	console.log(cookies);
+});
+
+// Set a cookie with the given cookie data;
+// may overwrite equivalent cookies if they exist.
+var cookie = { url : "http://www.github.com", name : "dummy_name", value : "dummy" };
+session.defaultSession.cookies.set(cookie, (error) => {
+	if (error) {
+    	console.error(error);
+	}
+});
+
+// In the main process.
+session.defaultSession.on('will-download', (event, item, webContents) => {
+	// Set the save path, making Electron not to prompt a save dialog.
+	item.setSavePath('/tmp/save.pdf');
+	console.log(item.getMimeType());
+	console.log(item.getFilename());
+	console.log(item.getTotalBytes());
+
+	item.on('updated', function() {
+		console.log('Received bytes: ' + item.getReceivedBytes());
+	});
+
+	item.on('done', function(e, state) {
+		if (state == "completed") {
+			console.log("Download successfully");
+		} else {
+			console.log("Download is cancelled or interrupted that can't be resumed");
+		}
+	});
+});
+
+// To emulate a GPRS connection with 50kbps throughput and 500 ms latency.
+session.defaultSession.enableNetworkEmulation({
+	latency: 500,
+	downloadThroughput: 6400,
+	uploadThroughput: 6400
+});
+
+// To emulate a network outage.
+session.defaultSession.enableNetworkEmulation({
+	offline: true
+});
+
+session.defaultSession.setCertificateVerifyProc((hostname, cert, callback) => {
+	callback((hostname === 'github.com') ? true : false);
+});
diff --git a/github-electron/github-electron.session.d.ts b/github-electron/github-electron.session.d.ts
index e1cef434f..523099b3c 100644
--- a/github-electron/github-electron.session.d.ts
+++ b/github-electron/github-electron.session.d.ts
@@ -3,40 +3,316 @@
 // Definitions by: jedmao <https://github.com/jedmao/>, rhysd <https://rhysd.github.io>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
+/// <reference path="github-electron.event-emitter.d.ts" />
+/// <reference path="github-electron.web-contents.d.ts" />
+
 declare namespace Electron {
-
-	class Session {
+	/**
+	 * The session module can be used to create new Session objects.
+	 * You can also access the session of existing pages by using
+	 * the session property of webContents which is a property of BrowserWindow.
+	 */
+	class Session extends EventEmitter {
+		/**
+		 * @returns a new Session instance from partition string.
+		 */
 		static fromPartition(partition: string): Session;
+		/**
+		 * @returns the default session object of the app.
+		 */
 		static defaultSession: Session;
-
-		cookies: any;
+		/**
+		 * Emitted when Electron is about to download item in webContents.
+		 * Calling event.preventDefault() will cancel the download
+		 * and item will not be available from next tick of the process.
+		 */
+		on(event: 'will-download', listener: (event: Event, item: DownloadItem, webContents: WebContents) => void): this;
+		on(event: string, listener: Function): this;
+		/**
+		 * The cookies gives you ability to query and modify cookies.
+		 */
+		cookies: SessionCookies;
+		/**
+		 * @returns the session’s current cache size.
+		 */
+		getCacheSize(callback: (size: number) => void): void;
+		/**
+		 * Clears the session’s HTTP cache.
+		 */
 		clearCache(callback: Function): void;
+		/**
+		 * Clears the data of web storages.
+		 */
 		clearStorageData(callback: Function): void;
+		/**
+		 * Clears the data of web storages.
+		 */
 		clearStorageData(options: ClearStorageDataOptions, callback: Function): void;
+		/**
+		 * Writes any unwritten DOMStorage data to disk.
+		 */
 		flushStorageData(): void;
+		/**
+		 * Sets the proxy settings.
+		 */
 		setProxy(config: string, callback: Function): void;
+		/**
+		 * Resolves the proxy information for url.
+		 */
 		resolveProxy(url: URL, callback: (proxy: any) => any): void;
+		/**
+		 * Sets download saving directory.
+		 * By default, the download directory will be the Downloads under the respective app folder.
+		 */
 		setDownloadPath(path: string): void;
+		/**
+		 * Emulates network with the given configuration for the session.
+		 */
 		enableNetworkEmulation(options: NetworkEmulationOptions): void;
+		/**
+		 * Disables any network emulation already active for the session.
+		 * Resets to the original network configuration.
+		 */
 		disableNetworkEmulation(): void;
+		/**
+		 * Sets the certificate verify proc for session.
+		 */
 		setCertificateVerifyProc(proc: CertificateVerifyProc): void;
+		/**
+		 * Clears the host resolver cache.
+		 */
+		clearHostResolverCache(callback: Function): void;
+		/**
+		 * The webRequest API set allows to intercept and modify contents of a request at various stages of its lifetime.
+		 */
 		webRequest: any;
 	}
 
 	interface ClearStorageDataOptions {
+		/**
+		 * Should follow window.location.origin’s representation scheme://host:port.
+		 */
 		origin?: string;
-		storages?: string[];
-		quotas?: string[];
+		/**
+		 *  The types of storages to clear.
+		 */
+		storages?: ('appcache' | 'cookies' | 'filesystem' | 'indexdb' | 'localstorage' | 'shadercache' | 'websql' | 'serviceworkers')[];
+		/**
+		 * The types of quotas to clear.
+		 */
+		quotas?: ('temporary' | 'persistent' | 'syncable')[];
 	}
 
 	interface NetworkEmulationOptions {
+		/**
+		 * Whether to emulate network outage.
+		 */
 		offline?: boolean;
+		/**
+		 * RTT in ms.
+		 */
 		latency?: number;
+		/**
+		 * Download rate in Bps.
+		 */
 		downloadThroughput?: number;
+		/**
+		 * Upload rate in Bps.
+		 */
 		uploadThroughput?: number;
 	}
 
 	interface CertificateVerifyProc {
 		(hostname: string, cert: any, callback: (accepted: boolean) => any): any;
 	}
+
+	/**
+	 * DownloadItem represents a download item in Electron.
+	 */
+	class DownloadItem extends EventEmitter {
+		/**
+		 * Emits when the downloadItem gets updated.
+		 */
+		on(event: 'updated', listener: Function): this;
+		/**
+		 * Emits when the download is in a terminal state. This includes a completed download,
+		 * a cancelled download (via downloadItem.cancel()), and interrupted download that can’t be resumed.
+		 */
+		on(event: 'done', listener: (event: Event, state: 'completed' | 'cancelled' | 'interrupted') => void): this;
+		on(event: string, listener: Function): this;
+		/**
+		 * Set the save file path of the download item.
+		 * Note: The API is only available in session’s will-download callback function.
+		 * If user doesn’t set the save path via the API, Electron will use the original
+		 * routine to determine the save path (Usually prompts a save dialog).
+		 */
+		setSavePath(path: string): void;
+		/**
+		 * Pauses the download.
+		 */
+		pause(): void;
+		/**
+		 * Resumes the download that has been paused.
+		 */
+		resume(): void;
+		/**
+		 * Cancels the download operation.
+		 */
+		cancel(): void;
+		/**
+		 * @returns The origin url where the item is downloaded from.
+		 */
+		getURL(): string;
+		/**
+		 * @returns The mime type.
+		 */
+		getMimeType(): string;
+		/**
+		 * @returns Whether the download has user gesture.
+		 */
+		hasUserGesture(): boolean;
+		/**
+		 * @returns The file name of the download item.
+		 * Note: The file name is not always the same as the actual one saved in local disk.
+		 * If user changes the file name in a prompted download saving dialog,
+		 * the actual name of saved file will be different.
+		 */
+		getFilename(): string;
+		/**
+		 * @returns The total size in bytes of the download item. If the size is unknown, it returns 0.
+		 */
+		getTotalBytes(): number;
+		/**
+		 * @returns The received bytes of the download item.
+		 */
+		getReceivedBytes(): number;
+		/**
+		 * @returns The Content-Disposition field from the response header.
+		 */
+		getContentDisposition(): string;
+	}
+
+	interface CookieFilter {
+		/**
+		 * Retrieves cookies which are associated with url. Empty implies retrieving cookies of all urls.
+		 */
+		url?: string;
+		/**
+		 * Filters cookies by name.
+		 */
+		name?: string;
+		/**
+		 * Retrieves cookies whose domains match or are subdomains of domains.
+		 */
+		domain?: string;
+		/**
+		 * Retrieves cookies whose path matches path.
+		 */
+		path?: string;
+		/**
+		 * Filters cookies by their Secure property.
+		 */
+		secure?: boolean;
+		/**
+		 * Filters out session or persistent cookies.
+		 */
+		session?: boolean;
+	}
+
+	interface Cookie {
+		/**
+		 * The name of the cookie.
+		 */
+		name: string;
+		/**
+		 * The value of the cookie.
+		 */
+		value: string;
+		/**
+		 * The domain of the cookie.
+		 */
+		domain: string;
+		/**
+		 * Whether the cookie is a host-only cookie.
+		 */
+		hostOnly: string;
+		/**
+		 * The path of the cookie.
+		 */
+		path: string;
+		/**
+		 * Whether the cookie is marked as secure.
+		 */
+		secure: boolean;
+		/**
+		 * Whether the cookie is marked as HTTP only.
+		 */
+		httpOnly: boolean;
+		/**
+		 * Whether the cookie is a session cookie or a persistent cookie with an expiration date.
+		 */
+		session: boolean;
+		/**
+		 * The expiration date of the cookie as the number of seconds since the UNIX epoch.
+		 * Not provided for session cookies.
+		 */
+		expirationDate?: number;
+	}
+
+	interface CookieDetails {
+		/**
+		 * The URL associated with the cookie.
+		 */
+		url: string;
+		/**
+		 * The name of the cookie.
+		 * Default: empty.
+		 */
+		name?: string;
+		/**
+		 * The value of the cookie.
+		 * Default: empty.
+		 */
+		value?: string;
+		/**
+		 * The domain of the cookie.
+		 * Default: empty.
+		 */
+		domain?: string;
+		/**
+		 * The path of the cookie.
+		 * Default: empty.
+		 */
+		path?: string;
+		/**
+		 * Whether the cookie should be marked as secure.
+		 * Default: false.
+		 */
+		secure?: boolean;
+		/**
+		 * Whether the cookie should be marked as HTTP only.
+		 * Default: false.
+		 */
+		httpOnly?: boolean;
+		/**
+		 * The expiration date of the cookie as the number of seconds since the UNIX epoch.
+		 * If omitted, the cookie becomes a session cookie.
+		 */
+		expirationDate?: number;
+	}
+
+	interface SessionCookies {
+		/**
+		 * Sends a request to get all cookies matching filter.
+		 */
+		get(filter: CookieFilter, callback: (error: Error, cookies: Cookie[]) => void): void;
+		/**
+		 * Sets the cookie with details.
+		 */
+		set(details: CookieDetails, callback: (error: Error) => void): void;
+		/**
+		 * Removes the cookies matching url and name.
+		 */
+		remove(url: string, name: string, callback: Function): void;
+	}
 }