diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..42ef285
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,96 @@
+import express from 'express'
+import webpack from 'webpack'
+import WebpackChainConfig from 'webpack-chain'
+
+export interface LogOptions {
+  logLevel: number
+  debug: boolean
+  silly: boolean
+  quiet: boolean
+  logUpdate: boolean
+}
+
+export interface Options extends LogOptions {
+  dev: boolean
+  baseDir: string
+  config: string | false
+  inspectWebpack: boolean
+}
+
+export interface WebpackConfigContext {
+  isServer: boolean
+  isClient: boolean
+  dev: boolean
+  type: string
+}
+
+export type ChainWebpackFn = (config: WebpackChainConfig, context: WebpackConfigContext) => void
+
+export type ConfigureWebpackFn = (config: webpack.Configuration, context: WebpackConfigContext) => void
+
+export type ConfigureServerFn = (server: express.Express) => void
+
+export type GeneratedRoutes = string[]
+
+export interface PluginDef {
+  name: string
+  apply: (ream: Ream) => void
+}
+
+export interface GenerateOptions {
+  routes: GeneratedRoutes
+}
+
+export interface Config {
+  entry: string
+  outDir: string
+  fsRoutes: boolean | {
+    baseDir: string
+    basePath: string
+    match: RegExp
+  }
+  transpileDependencies: string[]
+  runtimeCompiler: boolean
+  productionSourceMap: boolean
+  chainWebpack: ChainWebpackFn
+  configureWebpack: ConfigureWebpackFn
+  server: {
+    port: number
+    host: string
+  }
+  plugins: PluginDef[]
+  generate: GenerateOptions
+  css: {
+    extract: boolean
+  }
+  pwa: boolean
+  minimize: boolean
+  defaultBabelPreset: 'minimal' | false
+}
+
+export class Ream {
+  constructor(options?: Partial<Options>, config?: Partial<Config>)
+  chainWebpack(ChainWebpackFn): void
+  addGenerateRoutes(GeneratedRoutes): void
+  hasPlugin(string): PluginDef
+  loadPlugins(): void
+  createConfigs(): void
+  createCompilers(): void
+  build(): Promise<void>
+  generate(opts?: GenerateOptions): Promise<void>
+  generateOnly(opts?: GenerateOptions): Promise<void>
+  configureServer(fn: ConfigureServerFn): void
+  prepareFiles(): Promise<void>
+  writeCreateAppFile(): Promise<void>
+  writeEntryFile(): Promise<void>
+  getServer(): Promise<express.Express>
+  getRequestHandler(): Promise<express.Application>
+  start(): Promise<void>
+  prepareWebpack(): Promise<void>
+  prepareProduction(): Promise<void>
+  createRenderer({ serverBundle, clientManifest, serverType }: { serverBundle: string | object, clientManifest: object, serverType: 'generate' | 'production' }): void
+  resolveOutDir(...args): string
+  resolveBaseDir(...args): string
+}
+
+export default function ream(options?: Partial<Options>, config?: Partial<Config>): Ream
diff --git a/package.json b/package.json
index 6e1f875..a4dcd57 100644
--- a/package.json
+++ b/package.json
@@ -37,6 +37,9 @@
     "@babel/plugin-transform-runtime": "^7.0.0-beta.47",
     "@babel/preset-env": "^7.0.0-beta.47",
     "@babel/runtime": "^7.0.0-beta.47",
+    "@types/express": "^4.16.0",
+    "@types/webpack": "^4.4.20",
+    "@types/webpack-chain": "^5.0.0",
     "async-to-gen": "^1.4.0",
     "babel-helper-vue-jsx-merge-props": "^2.0.3",
     "babel-loader": "^8.0.0-beta.3",
diff --git a/yarn.lock b/yarn.lock
index b76838b..03de7ba 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -729,6 +729,102 @@
     into-stream "^3.1.0"
     lodash "^4.17.4"
 
+"@types/anymatch@*":
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/@types/anymatch/-/anymatch-1.3.0.tgz#d1d55958d1fccc5527d4aba29fc9c4b942f563ff"
+  integrity sha512-7WcbyctkE8GTzogDb0ulRAEw7v8oIS54ft9mQTU7PfM0hp5e+8kpa+HeQ7IQrFbKtJXBKcZ4bh+Em9dTw5L6AQ==
+
+"@types/body-parser@*":
+  version "1.17.0"
+  resolved "https://registry.yarnpkg.com/@types/body-parser/-/body-parser-1.17.0.tgz#9f5c9d9bd04bb54be32d5eb9fc0d8c974e6cf58c"
+  integrity sha512-a2+YeUjPkztKJu5aIF2yArYFQQp8d51wZ7DavSHjFuY1mqVgidGyzEQ41JIVNy82fXj8yPgy2vJmfIywgESW6w==
+  dependencies:
+    "@types/connect" "*"
+    "@types/node" "*"
+
+"@types/connect@*":
+  version "3.4.32"
+  resolved "https://registry.yarnpkg.com/@types/connect/-/connect-3.4.32.tgz#aa0e9616b9435ccad02bc52b5b454ffc2c70ba28"
+  integrity sha512-4r8qa0quOvh7lGD0pre62CAb1oni1OO6ecJLGCezTmhQ8Fz50Arx9RUszryR8KlgK6avuSXvviL6yWyViQABOg==
+  dependencies:
+    "@types/node" "*"
+
+"@types/events@*":
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/@types/events/-/events-1.2.0.tgz#81a6731ce4df43619e5c8c945383b3e62a89ea86"
+  integrity sha512-KEIlhXnIutzKwRbQkGWb/I4HFqBuUykAdHgDED6xqwXJfONCjF5VoE0cXEiurh3XauygxzeDzgtXUqvLkxFzzA==
+
+"@types/express-serve-static-core@*":
+  version "4.16.0"
+  resolved "https://registry.yarnpkg.com/@types/express-serve-static-core/-/express-serve-static-core-4.16.0.tgz#fdfe777594ddc1fe8eb8eccce52e261b496e43e7"
+  integrity sha512-lTeoCu5NxJU4OD9moCgm0ESZzweAx0YqsAcab6OB0EB3+As1OaHtKnaGJvcngQxYsi9UNv0abn4/DRavrRxt4w==
+  dependencies:
+    "@types/events" "*"
+    "@types/node" "*"
+    "@types/range-parser" "*"
+
+"@types/express@^4.16.0":
+  version "4.16.0"
+  resolved "https://registry.yarnpkg.com/@types/express/-/express-4.16.0.tgz#6d8bc42ccaa6f35cf29a2b7c3333cb47b5a32a19"
+  integrity sha512-TtPEYumsmSTtTetAPXlJVf3kEqb6wZK0bZojpJQrnD/djV4q1oB6QQ8aKvKqwNPACoe02GNiy5zDzcYivR5Z2w==
+  dependencies:
+    "@types/body-parser" "*"
+    "@types/express-serve-static-core" "*"
+    "@types/serve-static" "*"
+
+"@types/mime@*":
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/@types/mime/-/mime-2.0.0.tgz#5a7306e367c539b9f6543499de8dd519fac37a8b"
+  integrity sha512-A2TAGbTFdBw9azHbpVd+/FkdW2T6msN1uct1O9bH3vTerEHKZhTXJUQXy+hNq1B0RagfU8U+KBdqiZpxjhOUQA==
+
+"@types/node@*":
+  version "10.12.11"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-10.12.11.tgz#715c476c99a5f6898a1ae61caf9825e43c03912e"
+  integrity sha512-3iIOhNiPGTdcUNVCv9e5G7GotfvJJe2pc9w2UgDXlUwnxSZ3RgcUocIU+xYm+rTU54jIKih998QE4dMOyMN1NQ==
+
+"@types/range-parser@*":
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/@types/range-parser/-/range-parser-1.2.2.tgz#fa8e1ad1d474688a757140c91de6dace6f4abc8d"
+  integrity sha512-HtKGu+qG1NPvYe1z7ezLsyIaXYyi8SoAVqWDZgDQ8dLrsZvSzUNCwZyfX33uhWxL/SU0ZDQZ3nwZ0nimt507Kw==
+
+"@types/serve-static@*":
+  version "1.13.2"
+  resolved "https://registry.yarnpkg.com/@types/serve-static/-/serve-static-1.13.2.tgz#f5ac4d7a6420a99a6a45af4719f4dcd8cd907a48"
+  integrity sha512-/BZ4QRLpH/bNYgZgwhKEh+5AsboDBcUdlBYgzoLX0fpj3Y2gp6EApyOlM3bK53wQS/OE1SrdSYBAbux2D1528Q==
+  dependencies:
+    "@types/express-serve-static-core" "*"
+    "@types/mime" "*"
+
+"@types/tapable@*":
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/@types/tapable/-/tapable-1.0.4.tgz#b4ffc7dc97b498c969b360a41eee247f82616370"
+  integrity sha512-78AdXtlhpCHT0K3EytMpn4JNxaf5tbqbLcbIRoQIHzpTIyjpxLQKRoxU55ujBXAtg3Nl2h/XWvfDa9dsMOd0pQ==
+
+"@types/uglify-js@*":
+  version "3.0.4"
+  resolved "https://registry.yarnpkg.com/@types/uglify-js/-/uglify-js-3.0.4.tgz#96beae23df6f561862a830b4288a49e86baac082"
+  integrity sha512-SudIN9TRJ+v8g5pTG8RRCqfqTMNqgWCKKd3vtynhGzkIIjxaicNAMuY5TRadJ6tzDu3Dotf3ngaMILtmOdmWEQ==
+  dependencies:
+    source-map "^0.6.1"
+
+"@types/webpack-chain@^5.0.0":
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/@types/webpack-chain/-/webpack-chain-5.0.0.tgz#35a60c7e853640a4625047c2f8e43e4352d6a3c0"
+  integrity sha512-J4DNl1L4cF0Nwxe/tZiRU54iIjvv06ggxPBRMoE+J99y1yHOH+UzHo8UUIjLR9nMiiMqm1/C8yJMKllv7VxEeA==
+  dependencies:
+    "@types/webpack" "*"
+
+"@types/webpack@*", "@types/webpack@^4.4.20":
+  version "4.4.20"
+  resolved "https://registry.yarnpkg.com/@types/webpack/-/webpack-4.4.20.tgz#b2108461ac00d983ed966b0f781b451d6431a936"
+  integrity sha512-uSVhicDIkh2Phkn0L49eZQb4Ory5q9opiqhjxQGu+onh9mbPEhSF5OuA68dmH240VN1+mavQTmkQ1hqnKZB0gA==
+  dependencies:
+    "@types/anymatch" "*"
+    "@types/node" "*"
+    "@types/tapable" "*"
+    "@types/uglify-js" "*"
+    source-map "^0.6.0"
+
 "@vue/component-compiler-utils@^2.0.0":
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/@vue/component-compiler-utils/-/component-compiler-utils-2.1.2.tgz#75e7cc8496baecbb0994dc8783571d9ff07737fe"