Static site generator and rapid prototyping framework for Node.js, Grunt.js, and Yeoman and Gulp. Render templates with Handlebars, Lo-Dash or any template engine. Used by Less.js /, Topcoat, Web Experience Toolkit, and hundreds of other projects to build sites, themes, components, documentation, blogs and gh-pages.
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Latest commit df689e1 Dec 29, 2016 @jonschlinkert jonschlinkert 0.18.0


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Looking for the grunt plugin? Please visit grunt-assemble.

(Note that the current website, is for grunt-assemble. Thanks for your patience while we work on updating the site with documentation for the latest assemble).


Create a new assemble project in less than 3 minutes!

Install assemble

Install assemble's CLI globally:

$ npm install --global assemble

This adds the assemble command to your system path, allowing it to be run from any directory.

Create a new project

Scaffold out a new assemble project using [generate-assemble].

Install generate-assemble

$ npm install --global generate generate-assemble

Scaffold out a new assemble project

$ gen assemble

Run assemble

Time to build your assemble project!

$ assemble

This will give you a preview of how assemble works, continue reading for more information and documentation.

Table of contents

(TOC generated by verb using markdown-toc)


What is Assemble?

Assemble is a command line tool and developer framework for rapid prototyping, static site generation, and much more.

Who uses assemble?

Assemble is used by thousands of developers and teams in more than 170 countries! Here are a few examples of sites built with assemble:

Is your website, blog or project built with assemble? Please let us know about it!

Why should I use assemble?

  • Expressive, functional API (the API is also stable)
  • You can use assemble with any web framework or CSS/HTML toolkit
  • Assemble can build static sites or hybrid static/dynamic sites
  • Streams support, you can run any gulp plugin
  • Powerful features for rapid web development, including a robust API for rendering templates with any node.js template engine.
  • Assemble can use any base plugin
  • Assemble can do anything Jekyll does, but with more flexibility and control
  • Like gulp, assemble can also run any other static site generator as a plugin, which means you can do anything and everything all other node.js static site generators can do, and much more.

What can I do with Assemble?

Rapid development toolkit

Assemble can be used standalone, but it's even more powerful when used alongside the following libraries:

  • generate: scaffold out new projects from the command line
  • assemble: <= you are here
  • verb: generate documention for your projects
  • update: keep your projects up-to-date


Here are just a few of the features assemble offers:

Getting started

Installing assemble

To use assemble's CLI, you will first need to install it globally using npm:

$ npm --global install assemble

This adds the assemble command to your system path, allowing it to be run from any directory.

Rendering templates

Render a template (the default engine is handlebars, but you can use any engine you want):

var assemble = require('assemble');
var app = assemble();

// add a "page"  nd render it!'home.hbs', {content: 'This is {{title}}'})
  .render({title: 'Home!'}, function(err, view) {
    if (err) throw err;
    //=> 'This is Home!'

Running tasks

Create an assemblefile.js and add tasks to run:

var assemble = require('assemble');
var htmlmin = require('gulp-htmlmin');
var app = assemble();'a.hbs', {content: '...'});'b.hbs', {content: '...'});'c.hbs', {content: '...'});

app.task('default', function() {
  return app.toStream('pages') //<= push "pages" collection into stream
    .pipe(app.renderFile()) //<= render pages with default engine (hbs)
    .pipe(htmlmin()) //<= gulp plugin for minifying html
    .pipe(app.dest('site')); //<= write files to the "./site" directory

// expose your instance of assemble to assemble's CLI
module.exports = app;


Run assemble from the command line.

$ assemble <tasks> [options]

Running tasks

Specify one or more space-separated tasks to run.


Run task foo

$ assemble foo

Run tasks foo and bar

$ assemble foo bar

Specifying options

Non-task options are prefixed with --.


Set the --cwd to run an assemblefile.js in a different directory:

$ assemble --cwd=docs

Emit views as they're loaded and log them to stderr:

$ assemble --emit=view

See more command line options

Object expansion

Object-paths may be specified using dot-notation for either the key or value in a command line argument.

Additionally, assemble uses expand-object (and some custom parsing) to make it easier to pass non-trivial options and commands via command line. So all of the following formats are possible.


Boolean values:

$ assemble --foo 
# { foo: true }

Key-value pairs:

$ assemble --foo=bar
# { foo: 'bar' }

Nested booleans:

$ assemble --option=foo 
# {options: { foo: true }}

Nested key-value pairs:

$ assemble --option=foo:bar
# {options: { foo: 'bar' }}

Deeply nested key-value pairs:

$ assemble
# {options: foo: { bar: { baz: 'qux' }}}}

Or on the left-side of the =:

$ assemble
# {options: foo: { bar: { baz: 'qux' }}}}

Command line options


Change the cwd for the assemblefile.js to run, optionally specifying any tasks to run:

$ assemble <tasks> --cwd [directory]


To run the scaffolds example in the examples/ directory, you would enter:

$ assemble --cwd examples/scaffolds

If successful, in the command line, you should see something like this:

screen shot 2016-01-09 at 1 35 52 pm


Specify the name of the config file for assemble's CLI to run, the default is assemblefile.js.


$ assemble --file



Create an assemble app. This is the main function exported by the assemble module.


var assemble = require('assemble');
var app = assemble();


  • options {Object}: Optionally pass default options to use.

Templates API

Assemble exposes the entire API from the templates library for working with templates and template collections. The API is much more extensive than what is documented here, see templates for more documentation.

Templates and Views

In the following documentation, the terms "template" and "view" both refer to aspects of the same thing. Here's what they mean:

  • template: an actual template string
  • view: a object with a content property that contains the template string. Since views are instances of vinyl, you can think of a view as a "vinyl file for templates".


Create a template collection for caching views:

app.create('includes', {viewType: 'partial'});


  • cwd {String}: the base directory to use when loading templates onto the collection from a glob

  • viewType: {String|Array}: One or more view types to associate with the collection

Add views

Add a view to the collection:

app.include('', {contents: new Buffer('this is contents')});

Add multiple views:

  path: '', contents: new Buffer('this is contents'),
  path: '', contents: new Buffer('this is contents'),
  path: '', contents: new Buffer('this is contents')

// or pass a glob (optionally override `cwd` defined on `.create`)
app.includes('*.{md,hbs}', {cwd: 'templates/includes'});

View types

View types are defined on a collection to determine how a templates in the collection will be handled throughout the [render cycle][].

Available types

Assemble supports three view types:

  • partial: Views with this type are can be used as "partials" (or "partial views"), which can be injected into other views. Useful for components, document fragments, or other snippets of reusable code or content. These views are passed to rendering engines to be used as partials, or variables on the context if partials are not directly supported.
  • layout: allows views to "wrap" other views (of any type, including other layouts or partials) with common code or content.
  • renderable: Views that have a one-to-one relationship with rendered files that will eventually be visible to a user or visitor to a website. For example: pages or blog posts. The renderable view type is automatically set if no other view types are set.

Defining view types

You can define view types when a collection is created:

app.create('snippet', {viewType: 'partial'});

Or directly on the collection options:

app.snippets.option('viewType', ['partial']); // string or array


Register template engine for rendering views with the given ext:

app.engine(ext, fn);


  • ext {String}: The file extension of files to render with the engine
  • fn {Function}: Async function that follows consolidate engine conventions, and takes three arguments: str, locals and callback.


// this engine is already registered in assemble
app.engine('hbs', require('engine-handlebars'));

// create a custom engine
app.engine('txt', function(str, locals, cb) {
  // render `str` with `locals`
  cb(null, str);

You can tell assemble to use the same engine for all file extensions by setting a value on options.engine.


// use engine `hbs` for rendering all files
app.option('engine', 'hbs');

Or, if you're using .renderFile, you can force a specific engine to be used by passing the engine name.


Use the hbs engine to render all templates:



Render a view with the given locals and callback.

app.render(view, {title: 'Foo'}, function(err, view) {
  // `view` is an object with a rendered `content` property


  • view {Object|String}: The view to render
  • locals {Object}: Locals to pass to template engine for rendering templates in view
  • callback {Function}

File System API

Assemble offers the following low-level methods for working with the file system:

Assemble has first-class support for vinyl-fs, so any gulp plugin can be used in your assemble pipeline.


Create a vinyl stream. Takes glob patterns or filepaths to the source files to read.


  • glob {String|Array}: Glob patterns or file paths to source files.
  • options {Object}: Options or locals to merge into the context and/or pass to src plugins



// define `src` options
app.src('src/*.hbs', { layout: 'default' });


Specify a destination for processed files.


  • dest {String|Function}: File path or rename function.
  • options {Object}: Options and locals to pass to dest plugins




Copy files with the given glob patterns to the specified dest.


  • patterns {String|Array}: Glob patterns of files to copy.
  • dest {String|Function}: Desination directory.
  • returns {Stream}: Stream, to continue processing if necessary.


app.task('assets', function() {
  // return, to let assemble know when the task has completed
  return app.copy('assets/**', 'dist/');


Renders files as they are pushed through the stream.


Force a specific engine to be used for rendering files:

app.engine('txt', function(str, locals, cb) {
  cb(null, str);

  .pipe(app.renderfile('txt')) //<= use engine `txt`

Task API

Assemble has the following methods for running tasks and controlling workflows:


Define a task to be run when the task is called.


  • name {String}: Task name
  • fn {Function}: function that is called when the task is run.


app.task('default', function() {


Run one or more tasks.


  • tasks {Array|String}: Task name or array of task names.
  • cb {Function}: callback function that exposes err

Example['foo', 'bar'], function(err) {
  if (err) throw err;


Watch files, run one or more tasks when a watched file changes.


  • glob {String|Array}: Filepaths or glob patterns.
  • tasks {Array}: Task(s) to watch.


app.task('watch', function() {'docs/*.md', ['docs']);


Discovering plugins

Plugins from any applications built on base should work with Assemble and can be used in your assemblefile.js:

  • base: find base plugins on npm using the baseplugin keyword
  • assemble: find assemble plugins on npm using the assembleplugin keyword
  • generate: find generate plugins on npm using the generateplugin keyword
  • templates: find templates plugins on npm using the templatesplugin keyword
  • [update][update-plugin]: find update plugins on npm using the updateplugin keyword
  • verb: find verb plugins on npm using the verbplugin keyword

Authoring plugins

Visit the plugin documentation guide to learn how to use, author and publish plugins.



Get in touch!

Have questions, suggestions, or want to discuss assemble? Join the conversation on gitter or give us a shout on twitter. The assemble team and community are always happy to help!

More information


Website is outdated and being refactored!

Assemble's website,, only has information related to gulp-assemble. We're working hard to update the site with information about the latest release.

In the meantime, you might find the WIP docs useful. The unit tests are also great examples!

Is the assemble website up-to-date?

No, as mentioned above, it's completely out-of-date. If you're using grunt-assemble, some of the documentation at might still be useful. If you're using assemble v0.6.0 and higher, the documentation is probably wrong in almost every way.

We're actively (daily) working on a refactor and it's a very high priority.

What's the difference between assemble-core and assemble?

Assemble adds a CLI, a few built-in view collections: pages, layouts, and partials, middleware for parsing front-matter, and a few other basic defaults that we've found many users expect. If you'd prefer different defaults, assemble-core is a great starting point.

If you want something that handles templates, rendering, engines, helpers, collections, etc. but you don't need to run tasks or work with the file system, then consider using templates instead of assemble-core.

I use gulp, why is it recommended to use assemble directly, instead of running assemble with gulp?

You can run gulp plugins with assemble, but it won't always work the other way around. This is because, as a build system, assemble does things that gulp doesn't do, like handle middleware.

For example, assemble's .src and .dest methods have built-in .onStream, .preWrite, and .postWrite middleware handlers. If you still wish to use gulp and your build cycle includes middleware that requires these handlers, you can use the assemble-handle plugin with gulp to ensure that the handlers are still called as needed.

This is a long way of saying, you can find ways to make gulp work, but you would just be adding an extra dependency to your project to do things that assemble already does.

What is the relationship between gulp and assemble?

Please read our gulp FAQ for more information.



Are you using assemble in your project? Have you published an assemble project and want to share your project with the world?

Here are some suggestions!

  • If you get like Assemble and want to tweet about it, please feel free to mention @assemble or use the #assemble hashtag
  • Tell us about your assemble project
  • Show your love by starring Assemble and assemble
  • Get implementation help on StackOverflow (please use the assemble tag in questions)
  • Gitter Discuss Assemble with us on Gitter
  • If you publish an assemble plugin, thank you! To make your project as discoverable as possible, please add the keyword assembleplugin to package.json.


Please read our contributing guide if you'd like to learn more about contributing to this project.

Related projects

You might also be interested in these projects from @doowb and @jonschlinkert:

  • boilerplate: Tools and conventions for authoring and using declarative configurations for project "boilerplates" that can be… more | homepage
  • generate: Command line tool and developer framework for scaffolding out new GitHub projects. Generate offers the… more | homepage
  • scaffold: Conventions and API for creating declarative configuration objects for project scaffolds - similar in format… more | homepage
  • update: Be scalable! Update is a new, open source developer framework and CLI for automating updates… more | homepage
  • verb: Documentation generator for GitHub projects. Verb is extremely powerful, easy to use, and is used… more | homepage

Similar projects

If assemble doesn't do what you need, there are some other great open source projects you might be interested in, created by our friends on GitHub (in alphabetical order):

Static site generators

Blog frameworks

Release history


Changelog entries are classified using the following labels (from keep-a-changelog):

  • added: for new features
  • changed: for changes in existing functionality
  • deprecated: for once-stable features removed in upcoming releases
  • removed: for deprecated features removed in this release
  • fixed: for any bug fixes

Custom labels used in this changelog:

  • dependencies: bumps dependencies
  • housekeeping: code re-organization, minor edits, or other changes that don't fit in one of the other categories.






  • bump dependencies. In particular, there was a bug in parser-front-matter where leading whitespace was removed after extracting front-matter, which caused the first line of indentation to be removed. This has been fixed.


  • Added: .log() method, which also exposes additional methods, like, .log.success(), etc.
  • docs were moved to support/docs, so that markdown docs can be built to the docs directory
  • docs were updated, new docs added
  • Moves some private prototype methods to static methods, to allow them to be used without creating an instance
  • Bumps assemble-core to v0.25.0


  • Bumps assemble-core to v0.24.0 to get the latest versions of templates and base-data which removes the renameKey option from the .data method. Use the namespace option instead.


Bumps assemble-core to v0.22.0 to take advantage of fixes and improvements to lookup methods: .find and getView. No API changes were made. Please let us know if regressions occur.

  • fixes List bug that was caused collection helpers to explode
  • Improvements to lookup functions: app.getView() and app.find()
  • Bumps base to take advantages of code optimizations.


  • Bumps assemble-core to v0.21.0. Support for the queue property was removed on collections. See assemble-core for additional details.
  • Fixes bug where glob parent was not being used for file.base, causing dest directory to be relative to cwd instead of glob parent in some cases.
  • Some changes were made to context handling that effected one unit test out of ~1,000. although it's unlikely you'll be effected by the change, it warrants a minor bump
  • Externalizes common templates tests to base-test-runner, so that assemble plugins and other base applications can use the tests
  • Includes a fix from assemble-loader, where a bug caused renameKey to not always be used when defined on collection loader options.
  • Includes fixes from templates for resolving layouts


  • Bumps assemble-core to v0.18.0, which includes a bump in templates. See the changelog on the templates library for more details.


  • debug methods and related code have been removed
  • Bumps assemble-core to v0.17.0


  • Adds support for using es6 generators with tasks
  • Bumps assemble-core to v0.15.0


  • Bumps several dependencies. No API changes, this is mostly an optimization release. Be sure to completely remove node_modules and reinstall all dependencies to avoid errors such as isRegistered is not a function



  • Stability improvements and optimizations of the API introduced in v0.6.0.


  • Major refactor. Assemble was completely re-written from the ground-up as a standalone node.js library and is no longer a grunt plugin. Grunt plugin support has been moved to grunt-assemble. Please see that repo for additional details.


Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Please read the contributing guide for avice on opening issues, pull requests, and coding standards.

If Assemble doesn't do what you need, please let us know


Jon Schlinkert

Brian Woodward


Copyright © 2016, Jon Schlinkert. Released under the MIT license.

This file was generated by verb-generate-readme, v0.2.1, on December 29, 2016.