diff --git a/flow-typed/babel.js.flow b/flow-typed/babel.js.flow
new file mode 100644
index 00000000..5e0f1dea
--- /dev/null
+++ b/flow-typed/babel.js.flow
@@ -0,0 +1,139 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+type _SourceMap = {
+  file?: string,
+  mappings: string,
+  names: Array<string>,
+  sourceRoot?: string,
+  sources: Array<string>,
+  sourcesContent?: Array<?string>,
+  version: number,
+};
+
+// based on babylon v6.13.1
+type BabylonOptions = {
+  allowImportExportEverywhere?: boolean,
+  allowReturnOutsideFunction?: boolean,
+  allowSuperOutsideMethod?: boolean,
+  sourceType?: 'script' | 'module',
+  sourceFilename?: 'string',
+  plugins?: Array<
+    'jsx' | 'flow' | 'doExpressions' | 'objectRestSpread' | 'decorators' |
+    'classProperties' | 'exportExtensions' | 'asyncGenerators' |
+    'functionBind' | 'functionSent' | 'dynamicImport'
+  >,
+};
+
+// based on babel-generator v6.18.0
+type GeneratorOptions = {
+  auxiliaryCommentBefore?: string,
+  auxiliaryCommentAfter?: string,
+  shouldPrintComment?: (comment: string) => boolean,
+  retainLines?: boolean,
+  retainFunctionParens?: boolean,
+  comments?: boolean,
+  compact?: boolean | 'auto',
+  minified?: boolean,
+  concise?: boolean,
+  quotes?: 'single' | 'double',
+  filename?: string,
+  sourceMaps?: boolean,
+  sourceMapTarget?: string,
+  sourceRoot?: string,
+  sourceFileName?: string,
+};
+
+type InlinePlugin = string | {} | () => {};
+type _Plugins = Array<string | Object | [InlinePlugin] | [InlinePlugin, mixed]>;
+
+// based on https://babeljs.io/docs/usage/options/ -- 2016-11-11
+type __TransformOptions = {
+  filename?: string,
+  filenameRelative?: string,
+  presets?: Array<string | Object>,
+  plugins?: _Plugins,
+  parserOpts?: BabylonOptions,
+  generatorOpts?: GeneratorOptions,
+  highlightCode?: boolean,
+  only?: string | RegExp | Array<string | RegExp>,
+  ignore?: string | RegExp | Array<string | RegExp>,
+  auxiliaryCommentBefore?: boolean,
+  auxiliaryCommentAfter?: boolean,
+  sourceMaps?: boolean,
+  inputSourceMap?: ?Object,
+  sourceMapTarget?: string,
+  sourceFileName?: string,
+  sourceRoot?: string,
+  moduleRoot?: string,
+  moduleIds?: boolean,
+  moduleId?: string,
+  getModuleId?: (moduleName: string) => string,
+  resolveModuleSource?: (source: string, filename: string) => string,
+  code?: boolean,
+  babelrc?: boolean,
+  ast?: boolean,
+  compact?: boolean | 'auto',
+  minified?: boolean,
+  comments?: boolean,
+  shouldPrintComment?: (comment: string) => boolean,
+  retainLines?: boolean,
+  extends?: string,
+};
+
+type _TransformOptions =
+  __TransformOptions & {env?: {[key: string]: __TransformOptions}};
+declare class _Ast {}
+type TransformResult = {
+  ast: _Ast,
+  code: ?string,
+  ignored: boolean,
+  map: ?_SourceMap,
+};
+type VisitFn = <State>(path: Object, state: State) => any;
+
+declare module 'babel-core' {
+  declare type Plugins = _Plugins;
+  declare type SourceMap = _SourceMap;
+  declare type Ast = _Ast;
+  declare type TransformOptions = _TransformOptions;
+  declare function transform(
+    code: string,
+    options?: _TransformOptions,
+  ): TransformResult;
+  declare function traverse<State>(
+    ast: _Ast,
+    visitor: {[key: string]: VisitFn<State> |
+                             {enter?: VisitFn<State>, exit?: VisitFn<State>}},
+    scope?: ?Object,
+    state?: State,
+    parentPath?: ?Object,
+  ): void;
+  declare var types: {[key: string]: Function};
+  declare function transformFromAst(
+    ast: _Ast,
+    code?: ?string,
+    babelOptions?: _TransformOptions,
+  ): TransformResult;
+}
+
+type RawMapping = {
+  generated: {column: number, line: number},
+  name?: string,
+  original?: {column: number, line: number},
+  source?: string,
+};
+
+declare module 'babel-generator' {
+  declare type RawMapping = RawMapping;
+  declare function exports(
+    ast: _Ast,
+    options?: GeneratorOptions,
+  ): TransformResult & {rawMappings: ?Array<RawMapping>};
+}
diff --git a/flow-typed/uglify.js b/flow-typed/uglify.js
new file mode 100644
index 00000000..29a3e85a
--- /dev/null
+++ b/flow-typed/uglify.js
@@ -0,0 +1,71 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+'use strict';
+
+type _SourceMap = {
+  file?: string,
+  mappings: string,
+  names: Array<string>,
+  sourceRoot?: string,
+  sources: Array<string>,
+  sourcesContent?: Array<?string>,
+  version: number,
+};
+
+type _Result<MapT> = {
+  code: string,
+  map: MapT,
+};
+
+type _Options = {
+  compress?: false | {||},
+  fromString?: boolean,
+  inSourceMap?: string | ?_SourceMap,
+  mangle?: boolean | {|
+    except?: Array<string>,
+    toplevel?: boolean,
+    eval?: boolean,
+    keep_fnames?: boolean,
+  |},
+  mangleProperties?: boolean | {|
+    regex?: RegExp,
+    ignore_quoted?: boolean,
+    debug?: false | string,
+  |},
+  outFileName?: string,
+  output?: {|
+    ascii_only?: boolean,
+    screw_ie8?: boolean,
+  |},
+  parse?: {|
+    strict?: boolean,
+    bare_returns?: boolean,
+    filename?: string,
+  |},
+  sourceMapUrl?: string,
+  sourceRoot?: string,
+  warnings?: boolean,
+};
+
+type _Input =
+  | string // code or file name
+  | Array<string> // array of file names
+  | {[filename: string]: string}; // file names and corresponding code
+
+declare module 'uglify-js' {
+  declare function minify(
+    fileOrFilesOrCode: _Input,
+    options?: _Options & {outSourceMap?: ?false | ''},
+  ): _Result<void>;
+  declare function minify(
+    fileOrFilesOrCode: _Input,
+    options?: _Options & {outSourceMap: true | string},
+  ): _Result<string>;
+}