diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..7b9c239
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,154 @@
+declare module VueComponentCompiler {
+  /**
+   * Parse SFC file into block descriptors.
+   *
+   * @param content Contents of the SFC.
+   * @param filename Filepath (used for cache key & in generated source maps)
+   */
+  export function parse(content: string, filename: string, config: ParserConfig): SFCDescriptor
+
+  /**
+   * Compile styles for SFC
+   *
+   * @param styles List of styles to process.
+   * @param filename SFC file path
+   */
+  export function compileStyles(styles: Array<StyleCompilerSource>, filename: string, config: StyleCompilerConfig): Promise<Array<StyleCompilerOutput>>
+
+  /**
+   * Compile template to render functions
+   *
+   * @param template Template to compile
+   * @param filename SFC file path
+   */
+  export function compileTemplate(template: TemplateCompilerSource, filename: string, config: TemplateCompilerConfig): Promise<TemplateCompilerOutput>
+
+  export function assemble(source: AssemblerSource, filename: string, config: AssemblerConfig): string
+
+  type ParserConfig = {
+    needMap: boolean
+  }
+
+  type SFCDescriptor = {
+    script: ScriptDescriptor
+    styles: Array<StyleDescriptor>
+    template: TemplateDescriptor
+    customBlocks: Array<BlockDescriptor>
+  }
+
+  type BlockDescriptor = {
+    type: string // tag
+    content: string
+    start: number
+    end: number
+    attrs: Array<{ name: string, value: string | boolean}>
+  }
+
+  type StyleDescriptor = BlockDescriptor & {
+    scoped?: boolean
+    module?: string | boolean
+    lang?: string
+    src?: string
+  }
+
+  type ScriptDescriptor = BlockDescriptor & {
+    lang?: string
+    src?: string
+  }
+
+  type TemplateDescriptor = BlockDescriptor & {
+    lang?: string
+    src?: string
+  }
+
+  type CompilerSource = {
+    code: string
+    map?: object // prev source map
+  }
+
+  type StyleCompilerSource = CompilerSource & {
+    descriptor: StyleDescriptor
+  }
+
+  type StyleCompilerConfig = {
+    scopeId: string // used for scoped styles.
+    needMap?: boolean
+    plugins?: Array<object> // postcss plugins
+    options?: object // postcss options
+    onWarn?: MessageHandler
+  }
+
+  type MessageHandler = (message: Message) => void
+
+  type Message = {
+    type: string
+    text?: string
+  }
+
+  type CompilerOutput = {
+    code: string,
+    map?: object
+  }
+
+  type StyleCompilerOutput = CompilerOutput & {}
+
+  type TemplateCompilerSource = CompilerSource & {
+    descriptor: TemplateDescriptor
+  }
+
+  type TemplateCompilerConfig = {
+    isHot?: boolean // false
+    isServer?: boolean // false
+    isProduction?: boolean // true
+    optimizeSSR?: boolean // true
+    buble: object // see https://github.com/vuejs/vue-template-es2015-compiler/blob/master/index.js#L6
+    options?: {
+      preserveWhitspace?: boolean // true
+    }
+    transformToRequire?: object
+    plugins?: Array<Function>
+  }
+
+  type TemplateCompilerOutput = CompilerOutput & {
+    errors: Array<object>
+    tips: Array<object>
+  }
+
+  type AssemblerSource = {
+    script: {
+      id: string,
+      descriptor: ScriptDescriptor
+    }
+    styles: Array<{
+      id: string
+      hotPath: string
+      descriptor: StyleDescriptor
+    }>
+    render: {
+      id: string
+      descriptor: TemplateDescriptor
+    }
+    customBlocks: Array<{
+      id: string
+      descriptor: BlockDescriptor
+    }>
+  }
+
+  type AssemblerConfig = {
+    hashKey?: string
+    esModule?: boolean // true
+    shortFilePath?: string // = filename
+    require?: {
+      vueHotReloadAPI?: string // vue-hot-reload-api
+      normalizeComponent?: string // vue-component-compiler/src/normalize-component.js
+    }
+    moduleId: string // same as scopeId of style compiler.
+    moduleIdentifier?: string // autogenerated
+    isHot?: boolean // false
+    isServer?: boolean // false
+    isProduction?: boolean // true
+    isInjectable?: boolean // false
+    hasStyleInjectFn?: boolean // false
+    onWarn?: MessageHandler // console.warn
+  }
+}
diff --git a/src/assemble.js b/src/assemble.js
index dbf193d..4805e76 100644
--- a/src/assemble.js
+++ b/src/assemble.js
@@ -1,27 +1,12 @@
-const defaultsDeep = require('lodash.defaultsdeep')
+const defaults = require('lodash.defaultsdeep')
+const hash = require('hash-sum')
+
+const genId = require('./gen-id')
 
 const DISPOSED = 'disposed'
 const INJECT_STYLE_FN = 'injectStyle'
 const CSS_MODULES = 'cssModules'
 
-const defaultConfig = {
-  esModule: true,
-  filename: null,
-  shortFilePath: null,
-  require: {
-    vueHotReloadAPI: 'vue-hot-reload-api',
-    normalizeComponent: 'vue-component-compiler/src/normalize-component.js'
-  },
-  moduleId: null, // css scope id.
-  moduleIdentifier: null, // require for server.
-  isHot: false,
-  isServer: false,
-  isProduction: true,
-  isInjectable: false,
-  hasStyleInjectFn: false,
-  onWarn () {}
-}
-
 function _s (any) {
   return JSON.stringify(any)
 }
@@ -41,13 +26,29 @@ function __vue_type__ (type, id, esModule, addPrefix = true) {
   return output
 }
 
-module.exports = function assemble (script, render, styles, customBlocks, config) {
+module.exports = function assemble (source, filename, config) {
+  config = defaults(config, {
+    esModule: true,
+    shortFilePath: filename,
+    require: {
+      vueHotReloadAPI: 'vue-hot-reload-api',
+      normalizeComponent: 'vue-component-compiler/src/normalize-component.js'
+    },
+    moduleId: null,
+    moduleIdentifier: config.moduleIdentifier || hash(_s({ filename, config })), // require for server. TODO: verify this is correct.
+    isHot: false,
+    isServer: false,
+    isProduction: true,
+    isInjectable: false,
+    hasStyleInjectFn: false,
+    onWarn: message => console.warn(message)
+  })
+
   let output = ''
+  const { script, render, styles, customBlocks } = source
   const needsHotReload = !config.isProduction && config.isHot
   const hasScoped = styles.some(style => style.descriptor.scoped)
 
-  config = defaultsDeep({}, config, defaultConfig)
-
   if (config.isInjectable) config.esModule = false
 
   if (needsHotReload) output += `var ${DISPOSED} = false\n`
@@ -96,7 +97,7 @@ module.exports = function assemble (script, render, styles, customBlocks, config
               `  var oldLocals = ${CSS_MODULES}[${MODULE_KEY}]\n` +
               `  if (!oldLocals) return\n` +
               // 2. re-import (side effect: updates the <style>)
-              `  var newLocals = ${style.code}\n` +
+              `  var newLocals = ${requireString}\n` +
               // 3. compare new and old locals to see if selectors changed
               `  if (JSON.stringify(newLocals) === JSON.stringify(oldLocals)) return\n` +
               // 4. locals changed. Update and force re-render.
@@ -166,11 +167,11 @@ module.exports = function assemble (script, render, styles, customBlocks, config
         'console.error("named exports are not supported in *.vue files.")' +
       '}\n'
     // check functional components used with templates
-    if (render.code) {
+    if (render.id) {
       output +=
         'if (Component.options.functional) {' +
           'console.error("' +
-          '[vue-loader] ' + config.filename + ': functional components are not ' +
+          '[vue-loader] ' + filename + ': functional components are not ' +
           'supported with templates, they should use render functions.' +
         '")}\n'
     }
diff --git a/src/gen-id.js b/src/gen-id.js
new file mode 100644
index 0000000..e09733d
--- /dev/null
+++ b/src/gen-id.js
@@ -0,0 +1,13 @@
+// utility for generating a uid for each component file
+// used in scoped CSS rewriting
+var path = require('path')
+var hash = require('hash-sum')
+var cache = Object.create(null)
+var sepRE = new RegExp(path.sep.replace('\\', '\\\\'), 'g')
+
+module.exports = function genId (file, context, key) {
+  var contextPath = context.split(path.sep)
+  var rootId = contextPath[contextPath.length - 1]
+  file = rootId + '/' + path.relative(context, file).replace(sepRE, '/') + (key || '')
+  return cache[file] || (cache[file] = hash(file))
+}
diff --git a/src/parser.js b/src/parser.js
index 148d1c2..2b7e7f6 100644
--- a/src/parser.js
+++ b/src/parser.js
@@ -1,4 +1,5 @@
 const compiler = require('vue-template-compiler')
+const defaults = require('lodash.defaultsdeep')
 const LRU = require('lru-cache')
 const hash = require('hash-sum')
 const { SourceMapGenerator } = require('source-map')
@@ -7,14 +8,16 @@ const cache = LRU(100)
 const splitRE = /\r?\n/g
 const emptyRE = /^(?:\/\/)?\s*$/
 
-module.exports = function (content, filename, needMap) {
+module.exports = function (content, filename, config) {
+  config = defaults(config, { needMap: true })
+
   const cacheKey = hash(filename + content)
   const filenameWithHash = filename + '?' + cacheKey // source-map cache busting for hot-reloadded modules
 
   if (cache.has(cacheKey)) return cache.get(cacheKey)
 
   const output = compiler.parseComponent(content, { pad: 'line' })
-  if (needMap) {
+  if (config.needMap) {
     if (output.script && !output.script.src) {
       output.script.map = generateSourceMap(
         filenameWithHash,
diff --git a/src/style-compiler/index.js b/src/style-compiler/index.js
index 6e51027..1ad6f9d 100644
--- a/src/style-compiler/index.js
+++ b/src/style-compiler/index.js
@@ -1,25 +1,18 @@
 const postcss = require('postcss')
+const defaults = require('lodash.defaultsdeep')
 
 const trim = require('./plugins/trim')
 const scopeId = require('./plugins/scope-id')
 
-/**
- * Compile SFC style.
- *
- * @param {CompilerSource} style
- * @param {string} filename
- * @param {{plugins: object, options: object, needMap: boolean}} config
- */
-function compileStyle (style, filename, config = {}) {
-  const plugins = [trim].concat(config.plugins || [])
+function compileStyle (style, filename, config) {
+  const plugins = [trim].concat(config.plugins)
   const options = Object.assign({
     to: filename,
-    from: filename,
-    map: false
+    from: filename
   }, config.options)
 
   // source map
-  if (config.needMap && !options.map) {
+  if (config.needMap && !style.map) {
     if (!style.map) {
       throw Error('Previous source map is missing.')
     }
@@ -43,17 +36,23 @@ function compileStyle (style, filename, config = {}) {
     plugins.push(scopeId({ id: config.scopeId }))
   }
 
-  return postcss(plugins).process(style.code, options)
+  return postcss(plugins).process(style.code, options).then(result => {
+    const output = { code: result.css }
+
+    if (config.needMap) { output.map = result.map }
+    result.warnings().forEach(warning => config.onWarn(warning))
+
+    return output
+  })
 }
 
-module.exports =
-/**
- * Compile SFC styles.
- *
- * @param {CompilerSource[]} styles
- * @param {string} filename
- * @param {{plugins: object, options: object, needMap: boolean}} config
- */
-function compileStyles (styles, filename, config) {
+module.exports = function compileStyles (styles, filename, config) {
+  config = defaults(config, {
+    needMap: true,
+    plugins: [],
+    options: {},
+    onWarn: message => console.warn(message)
+  })
+
   return Promise.all(styles.map(style => compileStyle(style, filename, config)))
 }
diff --git a/src/template-compiler/index.js b/src/template-compiler/index.js
index a694d5c..4cf9729 100644
--- a/src/template-compiler/index.js
+++ b/src/template-compiler/index.js
@@ -1,15 +1,36 @@
 const compiler = require('vue-template-compiler')
 const transpile = require('vue-template-es2015-compiler')
+const defaults = require('lodash.defaultsdeep')
 const { js_beautify: beautify } = require('js-beautify')
 
 const transformRequire = require('./modules/transform-require')
 
 module.exports = function compileTemplate (template, filename, config) {
-  const options = Object.assign({
-    preserveWhitespace: true
-  }, config.options, {
-    modules: [transformRequire(config.transformToRequire)].concat(config.plugins || [])
-  })
+  config = defaults(
+    config,
+    {
+      isHot: false,
+      isServer: false,
+      isProduction: true,
+      optimizeSSR: true,
+      buble: {
+        transforms: {
+          stripWith: true
+        }
+      },
+      options: {
+        preserveWhitespace: true,
+        modules: []
+      },
+      plugins: []
+    }
+  )
+
+  const options = config.options
+
+  options.modules = options.modules.concat(config.plugins)
+  options.modules.push(transformRequire(config.transformToRequire))
+
   const compile = (config.isServer && config.optimizeSSR !== false && compiler.ssrCompile) ? compiler.ssrCompile : compiler.compile
   const compiled = compile(template.code, options)
   const output = {
@@ -31,11 +52,9 @@ module.exports = function compileTemplate (template, filename, config) {
 
     // mark with stripped (this enables Vue to use correct runtime proxy detection)
     if (
-      !config.isProduction && (
-      !config.buble ||
-      !config.buble.transforms ||
+      !config.isProduction &&
       config.buble.transforms.stripWith !== false
-    )) {
+    ) {
       output.code += `render._withStripped = true\n`
     }