diff --git a/types/lasso/index.d.ts b/types/lasso/index.d.ts
new file mode 100644
index 0000000000..64546a91c3
--- /dev/null
+++ b/types/lasso/index.d.ts
@@ -0,0 +1,53 @@
+// Type definitions for lasso 2.4
+// Project: https://github.com/lasso-js/lasso
+// Definitions by: Timur Manyanov <https://github.com/darkwebdev>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.4
+
+import Lasso, { LassoConfig, LassoResource, LassoPage } from './lib/Lasso';
+import LassoContext from './lib/LassoContext';
+
+export namespace transforms {
+  function createTransformer(unfilteredTransforms: any[], lassoContext: LassoContext, callback: (err: Error | null, result?: any) => any): void;
+}
+
+export namespace writers {
+  interface Writer {
+    lasso: Lasso;
+    config: LassoConfig;
+  }
+
+  function Writer(impl: any): Writer;
+  function fileWriter(fileWriterConfig: any, lassoConfig: LassoConfig): any;
+  function createWriter(impl: any): Writer;
+}
+
+export const defaultConfig: LassoConfig;
+
+export const defaultConfigBaseDir: string;
+
+export const defaultConfigFilename: string | null;
+
+export const lassoPage: LassoPage;
+
+export const lassoResource: LassoResource;
+
+export function getDefaultLasso(): Lasso;
+
+export function create(config?: LassoConfig | string, baseDir?: string, filename?: string): Lasso;
+
+export function configure(config?: LassoConfig | string, baseDir?: string, filename?: string): void;
+
+export function setDevelopmentMode(): void;
+
+export function createFlagSet(flags: any): any;
+
+export function isFlagSet(o: any): boolean;
+
+export function flushAllCaches(callback?: any): void;
+
+export function handleWatchedFileChanged(path: string): void;
+
+export function clearCaches(): void;
+
+export function getClientPath(path: string, options?: any): string;
diff --git a/types/lasso/lasso-tests.ts b/types/lasso/lasso-tests.ts
new file mode 100644
index 0000000000..bc944817ee
--- /dev/null
+++ b/types/lasso/lasso-tests.ts
@@ -0,0 +1,201 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import { transforms, configure, create, lassoPage, getDefaultLasso } from 'lasso';
+import { serveStatic } from 'lasso/middleware';
+import { enable } from 'lasso/node-require-no-op';
+import LassoContext from 'lasso/lib/LassoContext';
+import LassoPageResult from 'lasso/lib/LassoPageResult';
+
+// $ExpectType void
+configure('lasso-config.json');
+
+// $ExpectType void
+configure({});
+
+// $ExpectType Lasso
+create({});
+
+const lasso = getDefaultLasso();
+// $ExpectType Lasso
+lasso;
+
+// $ExpectType Promise<any>
+lassoPage({
+    name: 'my-page',
+    dependencies: [
+        './style.less',
+        'require-run: ./main'
+    ]
+},
+(err, lassoPageResult) => {
+    if (err) {
+        console.log('Failed to lasso page: ', err);
+        return;
+    }
+
+    // $ExpectType string
+    lassoPageResult.getHeadHtml();
+
+    // $ExpectType string
+    lassoPageResult.getBodyHtml();
+});
+
+lassoPage({
+    dependencies: [{
+        path: './hello-mobile.js',
+        'if-flag': 'mobile'
+    }],
+    flags: ['mobile', 'foo', 'bar']
+});
+
+configure({
+    cspNonceProvider(out) {
+        const res = out.stream;
+
+        return res.csp && res.csp.nonce;
+    }
+});
+
+configure({
+    require: {
+        extensions: [ '.js' ],
+        transforms: [ 'deamdify' ]
+    }
+});
+
+// $ExpectType Lasso
+lasso.on('afterLassoPage', (event) => {
+    const lassoPageResult: LassoPageResult = event.result;
+    const fingerprints = lassoPageResult.getInlineCodeFingerprints();
+    // $ExpectType string
+    fingerprints.map(fingerprint => `script-src 'self' 'sha256-${fingerprint}'`).join('; ');
+});
+
+const dependencies = lasso.dependencies;
+
+// $ExpectType void
+dependencies.registerJavaScriptType('my-js-type', require('./dependency-my-js-type')); // tslint:disable-line: no-var-requires
+
+// $ExpectType void
+dependencies.registerJavaScriptType('my-custom-type', {
+    properties: {
+        path: 'string'
+    },
+
+    init(context: any, callback: any) {
+        if (!this.path) {
+            throw new Error('"path" is required');
+        }
+
+        this.path = this.resolvePath(this.path);
+        callback();
+    },
+
+    read(context: any, callback: any) {
+        const path = this.path;
+
+        fs.readFile(path, {encoding: 'utf8'}, (err, src) => {
+            if (err) {
+                return callback(err);
+            }
+
+            // myCompiler.compile(src, callback);
+        });
+    },
+
+    getSourceFile() {
+        return this.path;
+    }
+});
+
+// $ExpectType void
+dependencies.registerStyleSheetType('my-custom-type', {});
+
+// $ExpectType void
+dependencies.registerPackageType('dir', {
+    properties: {
+        path: 'string'
+    },
+
+    init(context: any, callback: any) {
+        let path = this.path;
+
+        if (!path) {
+            callback(new Error('"path" is required'));
+        }
+
+        this.path = path = this.resolvePath(path);
+
+        fs.stat(path, (err, stat) => {
+            if (err) {
+                return callback(err);
+            }
+
+            if (!stat.isDirectory()) {
+                return callback(new Error('Directory expected: ' + path));
+            }
+
+            callback();
+        });
+    },
+
+    getDependencies(context: any, callback: any) {
+        const dir = this.path;
+
+        fs.readdir(dir, (err, filenames) => {
+            if (err) {
+                return callback(err);
+            }
+
+            const dependencies = filenames.map(filename => path.join(dir, filename));
+
+            callback(null, dependencies);
+        });
+    },
+
+    getDir() {
+        return this.path;
+    }
+});
+
+// $ExpectType void
+dependencies.registerRequireExtension('test', (path: string, context: any, callback: any) => {
+    callback(null, "exports.sayHello = function() { console.log('Hello!'); }");
+});
+
+// $ExpectType void
+lasso.lassoResource('path/to/foo.png', (err: any, result: any) => {
+    if (err) {
+        console.log(err);
+    } else {
+        const url = result.url;
+    }
+});
+
+// $ExpectType void
+lasso.addTransform(require('./my-transform')); // tslint:disable-line: no-var-requires
+
+// $ExpectType void
+lasso.addTransform({
+    contentType: 'js',
+    name: module.id,
+    stream: false,
+    transform(code: string, lassoContext: LassoContext) {
+        return code.toUpperCase();
+    }
+});
+
+// $ExpectType void
+transforms.createTransformer([], new LassoContext(), (err, result) => {});
+
+// $ExpectType RequestHandler
+serveStatic();
+
+// $ExpectType RequestHandler
+serveStatic({
+    lasso,
+    sendOptions: {}
+});
+
+// $ExpectType void
+enable();
diff --git a/types/lasso/lib/Lasso.d.ts b/types/lasso/lib/Lasso.d.ts
new file mode 100644
index 0000000000..56e0d195f5
--- /dev/null
+++ b/types/lasso/lib/Lasso.d.ts
@@ -0,0 +1,79 @@
+/// <reference types="node" />
+
+import { EventEmitter } from 'events';
+import LassoContext from './LassoContext';
+import { Bundle, DependencyConfig, DependencyRegistry } from './dependencies';
+import { writers } from '../index';
+import LassoPageResult from './LassoPageResult';
+
+export interface PageConfig {
+    name?: string;
+    dependencies: DependencyConfig[] | string[] | string | null;
+    flags?: string[];
+    from?: string;
+    packagePath?: string;
+    packagePaths?: string[];
+    lassoContext?: LassoContext;
+    cache?: any;
+    cacheKey?: string;
+    pageName?: string;
+    data?: any;
+}
+
+export type Callback = (err: Error | null, result?: any) => any;
+export type LassoPage = (options: PageConfig, callback?: (err: Error | null, result: LassoPageResult) => void) => Promise<any>;
+export type LassoResource = (path: string, options?: any, callback?: Callback) => void;
+
+export interface CustomPlugin {
+    plugin: string;
+    config: any;
+}
+
+export interface LassoConfig {
+    baseDir?: string;
+    plugins?: string[] | CustomPlugin[];
+    require?: any;
+    outputDir?: string;
+    urlPrefix?: string;
+    fingerprintsEnabled?: boolean;
+    includeSlotNames?: boolean;
+    minify?: boolean;
+    minifyJS?: boolean;
+    minifyCSS?: boolean;
+    minifyInlineOnly?: boolean;
+    minifyInlineJSOnly?: boolean;
+    minifyInlineCSSOnly?: boolean;
+    resolveCssUrls?: boolean;
+    relativeUrlsEnabled?: boolean;
+    bundlingEnabled?: boolean;
+    bundles?: Bundle[];
+    noConflict?: string;
+
+    cspNonceProvider?(out: any): string;
+    fingerprintInlineCode?(code: any): string;
+}
+
+export default class Lasso extends EventEmitter {
+    constructor(config: LassoConfig);
+
+    config: LassoConfig;
+    lassoCacheLookup: any;
+    dependencies: DependencyRegistry;
+    writer: writers.Writer;
+
+    initPlugins(): void;
+    createAppBundleMappings(bundleSetConfig: any, lassoContext: LassoContext, callback: Callback): any;
+    buildPageBundles(options: any, lassoContext: LassoContext, callback: Callback): void;
+    getAppBundleMappingsCached(bundleSetConfig: any, lassoContext: LassoContext, callback: Callback): void;
+    buildLassoCacheKey(lassoContext: LassoContext): { value: string; parts: string[]; };
+    getLassoCache(lassoContext: LassoContext): any;
+    getConfig(): LassoConfig;
+    getJavaScriptDependencyHtml(url: string, attributes?: any): string;
+    getCSSDependencyHtml(url: string, attributes?: any): string;
+    createLassoContext(options?: any): LassoContext;
+    setCSPNonceProvider(func: any): any;
+    addTransform(transform: any): void;
+    getDependencyRegistry(): DependencyRegistry;
+    lassoPage: LassoPage;
+    lassoResource: LassoResource;
+}
diff --git a/types/lasso/lib/LassoContext.d.ts b/types/lasso/lib/LassoContext.d.ts
new file mode 100644
index 0000000000..ae01277558
--- /dev/null
+++ b/types/lasso/lib/LassoContext.d.ts
@@ -0,0 +1,21 @@
+/// <reference types="node" />
+import { EventEmitter } from 'events';
+import Lasso from './Lasso';
+import { DependencyRegistry } from './dependencies';
+import { writers } from '../index';
+
+export default class LassoContext extends EventEmitter {
+  constructor();
+
+  LassoContext: boolean;
+  basePath?: string;
+  contentType?: string;
+  data?: any;
+  dependencyRegistry: DependencyRegistry;
+  flags: any[];
+  config: any;
+  writer: writers.Writer;
+  lasso: Lasso;
+  cache: any;
+  options: any;
+}
diff --git a/types/lasso/lib/LassoPageResult.d.ts b/types/lasso/lib/LassoPageResult.d.ts
new file mode 100644
index 0000000000..8d51ae052f
--- /dev/null
+++ b/types/lasso/lib/LassoPageResult.d.ts
@@ -0,0 +1,32 @@
+import LassoContext from './LassoContext';
+
+export default interface LassoPageResult {
+    addFile(filePath: string, contentType: string, isAsync: boolean, slot: any): void;
+    addUrl(url: string, slot: any, contentType: string, isAsync: boolean): void;
+    deserialize(reader: any, callback: any): void;
+    getBodyHtml(data?: any): string;
+    getCSSFiles(): any[];
+    getCSSUrls(): any[];
+    getFileByAsyncBundleName(bundleName: string): any;
+    getFileByBundleName(bundleName: string): any;
+    getFilePathsByContentType(...args: any[]): void;
+    getHeadHtml(data?: any): string;
+    getHtmlBySlot(): any;
+    getHtmlForSlot(slotName: string, data?: any): any;
+    getInlineCodeFingerprints(): string[];
+    getJavaScriptFiles(): any[];
+    getJavaScriptUrls(): any[];
+    getOutputFiles(): any[];
+    getOutputFilesWithInfo(...args: any[]): void;
+    getSlotHtml(slotName: string, data?: any): any;
+    getUrlByAsyncBundleName(bundleName: string): any;
+    getUrlByBundleName(bundleName: string): any;
+    getUrlsForSlot(slot: any): any;
+    htmlSlotsToJSON(indentation: any): any;
+    registerBundle(bundle: any, async: any, lassoContext: LassoContext): void;
+    registerResource(resource: any): void;
+    serialize(lassoPageResult: LassoPageResult): any;
+    setHtmlBySlot(htmlBySlot: any): void;
+    setInlineCodeFingerprints(inlineCodeFingerprints: string[]): void;
+    toJSON(): any;
+}
diff --git a/types/lasso/lib/dependencies.d.ts b/types/lasso/lib/dependencies.d.ts
new file mode 100644
index 0000000000..682b6b3c30
--- /dev/null
+++ b/types/lasso/lib/dependencies.d.ts
@@ -0,0 +1,112 @@
+/// <reference types="node" />
+
+import LassoContext from './LassoContext';
+import { EventEmitter } from 'events';
+
+export type Callback = (err: Error | null, result?: any) => any;
+
+export interface Bundle {
+    name: string;
+    dependencies: Array<DependencyConfig | string>;
+}
+
+export interface DependencyConfig {
+    type?: string;
+    attributes?: {
+        integrity: string;
+        crossorigin: string;
+    };
+    inline?: string;
+    slot?: string;
+    'css-slot'?: string;
+    'js-slot'?: string;
+    url?: string;
+    path?: string;
+    external?: boolean;
+    'if-flag'?: string;
+    'if-not-flag'?: string;
+    if?: string;
+    from?: string;
+    to?: string;
+    require?: string;
+    'require-run'?: string;
+    dependencies?: Array<DependencyConfig | string>;
+}
+
+export interface Dependency extends EventEmitter, DependencyConfig {
+    _packageDependency?: boolean;
+    contentType?: string;
+    properties?: { [key: string]: string };
+
+    (dependencyConfig: DependencyConfig, dirname: string, filename?: string): Dependency;
+    calculateKey(lassoContext: LassoContext, callback: Callback): any;
+    doCalculateKey(lassoContext: LassoContext, callback: Callback): any;
+    calculateKeyFromProps(): string;
+    createPackageManifest(manifest?: any, dirname?: string, filename?: string): any;
+    createReadStream(lassoContext: LassoContext): any;
+    doGetLastModified(lassoContext: any, callback: Callback): any;
+    getContentType(): any;
+    getDefaultBundleName(pageBundleName?: string, lassoContext?: LassoContext): string;
+    getDir(): string | null;
+    getFileLastModified(path: string, callback: Callback): any;
+    getJavaScriptSlot(): any;
+    getKey(): any;
+    getLastModified(lassoContext: LassoContext, callback: Callback): any;
+    getPackageManifest(lassoContext: LassoContext, callback: Callback): any;
+    getParentManifestDir(): string;
+    getParentManifestPath(): string;
+    getPropsKey(): any;
+    getReadCacheKey(): any;
+    getSlot(): any;
+    getSourceFile(): any;
+    getStyleSheetSlot(): any;
+    hasContent(): boolean;
+    hasModifiedFingerprint(): boolean;
+    init(lassoContext: LassoContext, callback: Callback): any;
+    doInit(lassoContext: LassoContext, callback: Callback): void;
+    inspect(): any;
+    isCompiled(): boolean;
+    isExternalResource(): boolean;
+    isInPlaceDeploymentAllowed(): boolean;
+    isJavaScript(): boolean;
+    isPackageDependency(): boolean;
+    isPageBundleOnlyDependency(): boolean;
+    isStyleSheet(): boolean;
+    onAddToAsyncPageBundle(bundle: Bundle, lassoContext: LassoContext): void;
+    onAddToPageBundle(bundle: Bundle, lassoContext: LassoContext): void;
+    read(context: any, callback: Callback): any;
+    resolvePath(path: string, from?: string): string;
+    set(props: any): void;
+    shouldCache(lassoContext: LassoContext): boolean;
+}
+
+export interface DependencyRegistry {
+    registeredTypes: any;
+    extensions: any;
+    requireExtensions: any;
+    requireExtensionNames: any;
+
+    addNormalizer(normalizerFunc: any): any;
+    createDependency(config: any, dirname: string, filename?: string): any;
+    createRequireHandler(path: string, lassoContext: LassoContext, userOptions: any): any;
+    createResourceTransformType(transformFunc: any): any;
+    getRequireExtensionNames(): any;
+    getRequireHandler(path: string, lassoContext: LassoContext): any;
+    getType(type: string): any;
+    normalizeDependencies(dependencies: any[], dirname: string, filename: string, callback: Callback): any;
+    registerDefaults(): void;
+    registerExtension(extension: string, type: string): void;
+    registerJavaScriptType(type: string, mixins: any): void;
+    registerPackageType(type: string, mixins: any): void;
+    registerRequireExtension(ext: string, options: any): void;
+    registerRequireType(type: string, options: any): void;
+    registerStyleSheetType(type: string, mixins: any): void;
+    registerType(type: string, mixins: any): void;
+    typeForPath(path: string): string;
+}
+
+export function createRegistry(): DependencyRegistry;
+
+export function isRegistry(o: any): boolean;
+
+export function isDependency(d: any): boolean;
diff --git a/types/lasso/middleware.d.ts b/types/lasso/middleware.d.ts
new file mode 100644
index 0000000000..948de1a03f
--- /dev/null
+++ b/types/lasso/middleware.d.ts
@@ -0,0 +1,9 @@
+import { RequestHandler } from 'express';
+import Lasso from './lib/Lasso';
+
+export interface MiddlewareOptions {
+  lasso?: Lasso;
+  sendOptions?: any;
+}
+
+export function serveStatic(options?: MiddlewareOptions): RequestHandler;
diff --git a/types/lasso/node-require-no-op.d.ts b/types/lasso/node-require-no-op.d.ts
new file mode 100644
index 0000000000..713a4aafe4
--- /dev/null
+++ b/types/lasso/node-require-no-op.d.ts
@@ -0,0 +1 @@
+export function enable(...extensions: string[]): void;
diff --git a/types/lasso/tsconfig.json b/types/lasso/tsconfig.json
new file mode 100644
index 0000000000..2386e1e1f5
--- /dev/null
+++ b/types/lasso/tsconfig.json
@@ -0,0 +1,29 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "dom",
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "lasso-tests.ts",
+        "middleware.d.ts",
+        "node-require-no-op.d.ts",
+        "lib/dependencies.d.ts",
+        "lib/Lasso.d.ts",
+        "lib/LassoContext.d.ts"
+    ]
+}
diff --git a/types/lasso/tslint.json b/types/lasso/tslint.json
new file mode 100644
index 0000000000..f93cf8562a
--- /dev/null
+++ b/types/lasso/tslint.json
@@ -0,0 +1,3 @@
+{
+    "extends": "dtslint/dt.json"
+}