Giter8 is a command line tool to generate files and directories from templates published on GitHub or any other git repository. It’s implemented in Scala and runs through the sbt launcher, but it can produce output for any purpose.

sbt new integration 

Starting sbt 0.13.13, Giter8 can be called from sbt’s "new" command as follows:

$ sbt new scala/scala-seed.g8


  • Original implementation (C) 2010-2015 Nathan Hamblen and contributors
  • Adapted and extended in 2016 by foundweekends project

Giter8 is licensed under Apache 2.0 license



Giter8 and other Scala command line tools can be installed using Coursier. See the coursier installation instruction to add it to your path. Once cs is on your path, you can install giter8 with this command:

$ cs install giter8

and update it using:

$ cs update g8


It’s possible to manually download and install giter8 directly from Maven Central:

$ curl > ~/bin/g8
$ chmod +x ~/bin/g8

Replace ~/bin/ with anything that is on your PATH. To make sure everything is working, try running g8 with no parameters, you should see

Error: Missing argument <template>
Try --help for more information.


Template repositories can reside on GitHub and should be named with the suffix .g8. We’re keeping a list of templates on the wiki.

To apply a template, for example, unfiltered/unfiltered.g8:

$ g8 unfiltered/unfiltered.g8

Giter8 resolves this to the unfiltered/unfiltered.g8 repository and queries GitHub for the project’s template parameters. Alternatively, you can also use a git repository full name

$ g8

or even a local template, using the file:// protocol:

$ g8 file://path/to/template

For remote or local repositories it’s possible to fetch a specific branch, a specific tag or even a specific directory using command-line arguments:

-b, --branch <value>     Resolve a template within a given branch
-t, --tag <value>        Resolve a template within a given tag
-d, --directory <value>  Resolve a template within the given 
                         subdirectory in the repo

The default enclosing directory is ..

You’ll be prompted for each parameter, with its default value in square brackets:

name [My Web Project]: 

Enter your own value or press enter to accept the default. After all values have been supplied, giter8 fetches the templates, applies the parameters, and writes them to your filesystem.

If the template has a name parameter, it will be used to create base directory in the current directory (typical for a new project). Otherwise, giter8 will output its files and directories into the current directory, skipping over any files that already exist.

An output directory can be specified:

-o, --out <value>        Output directory

this will override the generation of the directory’s name according to the value of the name variable and the current directory as the enclosing one.

To overwrite existing files in the destination folder, you can use:

-f, --force              Force overwrite of any existing files in 
                         output directory

Once you become familiar with a template’s parameters, you can enter them on the command line and skip the interaction:

$ g8 unfiltered/unfiltered.g8 --name=my-new-website

Any unsupplied parameters are assigned their default values.

Private Repositories 

Giter8 will use your ssh key to access private repositories, just like git does.

SSH Agent 

Giter8 now support proxying to an SSH Agent which can be useful if you are using another SSH agent such as gpg-agent.

Consider the following example:


[url "ssh://"]
    insteadOf =


export SSH_AUTH_SOCK="$(gpgconf --list-dirs agent-ssh-socket)"
gpgconf --launch gpg-agent 

Then this would have previously failed with:

$ g8 unfiltered/unfiltered.g8

ssh:// Auth fail

This now works provided that the GitHub public key is in your known hosts file.

You can do this by running:

$ ssh -T

Optionally the known hosts file can be overridden using:

-h, --known-hosts <value>  SSH known hosts file. If unset the location 
                           will be guessed.

Making your own templates 

Use CC0 1.0 for template licensing 

We recommend licensing software templates under CC0 1.0, which waives all copyrights and related rights, similar to the “public domain.”

If you reside in a country covered by the Berne Convention, such as the US, copyright will arise automatically without registration. Thus, people won’t have legal right to use your template if you do not declare the terms of license. The tricky thing is that even permissive licenses such as MIT License and Apache License will require attribution to your template in the template user’s software. To remove all claims to the templated snippets, distribute it under CC0, which is an international equivalent to public domain.

Template license
[other author/contributor lines as appropriate]

To the extent possible under law, the author(s) have dedicated all copyright and related
and neighboring rights to this template to the public domain worldwide.
This template is distributed without any warranty. See <>.

template layout 

The g8 runtime looks for templates in two locations in a given GitHub project:

  • If the src/main/g8 directory is present it uses src/main/g8 (src layout)
  • If it does not exist, then the root directory is used (root layout)

src layout 

This src layout is recommended so that it is easy for the template itself to be an sbt project. That way, an sbt plugin can be employed to locally test templates before pushing changes to GitHub.

The easy way to start a new template project is with a Giter8 template made expressly for that purpose:

$ g8 foundweekends/giter8.g8

This will create an sbt project with stub template sources nested under src/main/g8. The file defines template fields and their default values using the Java properties file format. file may be placed in project/ directory, or directly under the root of the template. Properties are simple keys and values that replace them.

StringTemplate is the engine that applies Giter8 templates, so template fields in source files are bracketed with the $ character. For example, a “classname” field might be referenced in the source as:

class $classname$ {

The template fields themselves can be utilized to define the defaults of other fields. For instance, you could build some URLs given the user’s GitHub id:

name = URL Builder

This would yield the following in interactive mode:

name [URL Builder]: my-proj
github_id [githubber]: n8han
project_url []:
developer_url []:

Dollar signs can be escaped to avoid resolution:

val foo = "foo"
val bar = "bar"

This would yield to:

val foo = "foo"
val bar = "bar"

Some variable names are prohibited since they’re tokens used by StringTemplate in its grammar, the complete list is here but the most common are:

"i", "i0", "if", "else", "elseif", "endif", "first", "length"
"strlen", "last", "rest", "reverse", "trunc", "strip", "trim"

Template comments 

Sometimes it’s useful to put a comment into a template that is intended for template maintainers, and should not be included in the generated output.

Wrapping comments between $! and !$ won’t make them appear in the output.

$! This comment won't appear in the output !$
// This comment will appear in the output
This multiline comment won't appear either
No matter how
long it is

Internal $substitutions$ are ignored.

Even $invalid$ ones.

 * This comment is output and can contain $substitutions$


All fields have a property named truthy to be used in conditional expressions. "y", "yes", and "true" evaluate to true; anything else evaluates to false.

scala212 = yes
scala211 = no

These could be used in a template as follows:

scalaVersion := "2.12.3"
scalaVersion := "2.11.11"
scalaVersion := "2.10.6"

These could also be used include/exclude files or directories:

├── $name__normalize$
│   ├── $if(jvm.truthy)$jvm$endif$
│   │   └── src
│   │       └── main
│   │           └── scala
│   │               └── $organization__packaged$
│   │                   └── $name;format="Camel"$.scala

If you want to skip a directory from the path, but keep all nested directories and files, use . as the name of the directory. For example the next template:

├── parent_folder
│   ├── $if(cond.truthy)$skip_folder$else$.$endif$
|   |   └── child_file

will be processed to

├── parent_folder
|   └── child_file

name field 

The name field, if defined, is treated specially by Giter8. It is assumed to be the name of a project being created, so the g8 runtime creates a directory based off that name (with spaces and capitals replaced) that will contain the template output. If no name field is specified in the template, g8’s output goes to the user’s current working directory. In both cases, directories nested under the template’s source directory are reproduced in its output. File and directory names also participate in template expansion, e.g.


package field 

The package field, if defined, is assumed to be the package name of the user’s source. A directory named $package$ expands out to package directory structure. For example, net.databinder becomes net/databinder.

verbatim field 

The verbatim field, if defined, is assumed to be the space delimited list of file patterns such as *.html *.js. Files matching verbatim pattern are excluded from string template processing.

Maven properties 

maven properties tell Giter8 to query the Central Maven Repository. Instead of supplying a particular version (and having to update the template with every release), specify a library and giter8 will set the value to the latest version according to Maven Central.

The property value format is maven(groupId, artifactId). Keep in mind that Scala projects are typically published with a Scala version identifier in the artifact id. So for the Unfiltered library, we could refer to the latest version as follows:

name = My Template Project
description = Creates a giter8 project template.
unfiltered_version = maven(ws.unfiltered, unfiltered_2.11)

To only use the latest stable release (excluding Milestone builds, Release candidates etc) specify a “stable” value in the property value format maven(groupId, artifactId, stable). To use the latest stable version for the Scalatest library we could refer to it as follows:

name = My Template Project
description = Creates a giter8 project template.
scalatest_version = maven(org.scalatest, scalatest_2.11, stable)

root layout 

There’s an experimental layout called root layout, which uses the root directory of the GitHub project as the root of template.

Since you can no longer include template fields in the files under project its application is very limited. It might be useful for templates that are not for sbt builds or templates without any fields.

Formatting template fields 

Giter8 has built-in support for formatting template fields. Formatting options can be added when referencing fields. For example, the name field can be formatted in upper camel case with:


The formatting options are:

upper      | uppercase       : all uppercase letters
lower      | lowercase       : all lowercase letters
cap        | capitalize      : uppercase first letter
decap      | decapitalize    : lowercase first letter
start      | start-case      : uppercase the first letter of each word
word       | word-only       : remove all non-word letters (only a-zA-Z0-9_)
space      | word-space      : replace all non-word letters (only a-zA-Z0-9) with a whitespace
Camel      | upper-camel     : upper camel case (start-case, word-only)
camel      | lower-camel     : lower camel case (start-case, word-only, decapitalize)
hyphen     | hyphenate       : replace spaces with hyphens
norm       | normalize       : all lowercase with hyphens (lowercase, hyphenate)
snake      | snake-case      : replace spaces and dots with underscores
dotReverse | dot-reverse     : tokenizes by dot and reverses the tokens ( -> org.scala-lang)
package    | package-naming  : replace spaces with dots
packaged   | package-dir     : replace dots with slashes (net.databinder -> net/databinder)
random     | generate-random : appends random characters to the given string

A name field with a value of My Project could be rendered in several ways:

$name$ -> "My Project"
$name;format="camel"$ -> "myProject"
$name;format="Camel"$ -> "MyProject"
$name;format="normalize"$ -> "my-project"
$name;format="lower,hyphen"$ -> "my-project"

Note that multiple format options can be specified (comma-separated) which will be applied in the order given.

For file and directory names a format option can be specified after a double underscore. For example, a directory named $organization__packaged$ will change org.somewhere to org/somewhere like the built-in support for package. A file named $name__Camel$.scala and the name awesome project will create the file AwesomeProject.scala. Multiple comma separated formatting options can be used at once: $name__lower,hyphen$.scala and the name Awesome Project will create the file awesome-project.scala.

Testing templates locally 

Templates may be passed to the g8 command with a file:// URL, and in this case the template is applied as it is currently saved to the file system. In conjunction with the --force option which overwrites output files without prompting, you can test changes to a template as you are making them.

For example, if you have the Unfiltered template cloned locally you could run a command like this:

$ g8 file://unfiltered.g8/ --name=uftest --force

In a separate terminal, test out the template.

$ cd uftest/
$ sbt
> ~ compile

To make changes to the template, save them to its source under the .g8 directory, then repeat the command to apply the template in the original terminal:

$ g8 file://unfiltered.g8/ --name=uftest --force

Your uftest sbt session, waiting with the ~ compile command, will detect the changes and automatically recompile.

Using the Giter8Plugin 

Giter8 supplies an sbt plugin for testing templates before pushing them to a GitHub branch. If you used the foundweekends/giter8.g8 template recommended above, it should already be configured.

If you need to upgrade an existing template project to the current plugin, you can add it as a source dependency in project/giter8.sbt:

addSbtPlugin("org.foundweekends.giter8" % "sbt-giter8" % "0.16.2")

When you enter sbt’s shell in the base directory of a template project that is configured to use this plugin, the action g8Test will apply the template in the default output directory (under target/sbt-test) and run the scripted test for that project in a forked process. You can supply the test scripted as project/giter8.test or src/test/g8/test, otherwise >test is used. This is a good sanity check for templates that are supposed to produce sbt projects.

But what if your template is not for an sbt project?


You can still use sbt’s shell to test the template. The lower level g8 action will apply default field values to the template and write it to the same target/g8 directory.

As soon as you push your template to GitHub (remember to name the project with a .g8 extension) you can test it with the actual g8 runtime. When you’re ready, add your template project to the the wiki so other giter8 users can find it.

Using Mill 

There is also an external Mill plugin that can be used to test your templates as well. An example setup can be found below:

import $ivy.`io.chris-kipp::mill-giter8::0.2.0`

import io.kipp.mill.giter8.G8Module

object g8 extends G8Module {
  override def validationTargets =
    Seq("example.compile", "example.fix", "example.reformat")

This plugin only supports `src` layouts, but gives you some useful targets like g8.validate which will both test the generation of your template and also ensure any targets defined with validationTargets can also be ran against your generated project.

Scaffolding plugin 

Giter8 supplies an sbt plugin for creating and using scaffolds.

Using the scaffold plugin 

Add the following lines in project/scaffold.sbt

addSbtPlugin("org.foundweekends.giter8" % "sbt-giter8-scaffold" % "0.16.2")

Once done, the g8Scaffold command can be used in the sbt shell. Use TAB completion to discover available templates.

> g8Scaffold <TAB>
controller   global       model

To overwrite existing files pass the --force flag after the template:

> g8Scaffold model --force

The template plugin will prompt each property that needed to complete the scaffolding process:

> g8Scaffold controller
className [Application]:

Creating a scaffold 

The g8 runtime looks for scaffolds in the src/main/scaffolds in the given GitHub project. Each directory inside src/main/scaffolds is a different scaffold, and will be accessible in the sbt shell using the directory name. Scaffold directories may have a file to define field values, just like ordinary templates. name is again a special field name: if it exists, the scaffold will be generated into a directory based on name, with subdirectories following the layout of the source scaffold directory.

Once a template as been used, scaffolds are stored into <project_root>/.g8

$ ls sample/.g8
total 0
drwxr-xr-x   5 jtournay  staff   170B Aug  6 03:21 .
drwxr-xr-x  11 jtournay  staff   374B Aug  6 05:29 ..
drwxr-xr-x   4 jtournay  staff   136B Aug  6 03:21 controller
drwxr-xr-x   4 jtournay  staff   136B Aug  6 03:21 global
drwxr-xr-x   4 jtournay  staff   136B Aug  6 03:21 model

It’s also possible to create your own scaffold in any sbt project by creating the .g8 directory.


Installing local version of giter8 

When you’re working on giter8 locally you probably want to try out your changes before you open a pull request. This is how you do it.

Giter8 uses [conscript] as distribution mechanism. You can find more documentation about conscript on its [official page].

Fixing PATH: 

Before you install giter8 with conscript, you need to ensure, that conscript directory has higher precedence than default installation path.

You can either delete existing version of giter8, or change PATH variable such that ~/.conscript/bin is before.

To install local version: 

  • Change g8version in build.sbt i.e. by adding "-SNAPSHOT";
  • Run publishLocal from sbt;
  • From a shell session run cs --local foundweekends/giter8/<YOUR_VERSION>. Use the version number you just wrote in build.sbt.

To refresh: 

  • Run publishLocal from sbt again;
  • From a shell session run cs --clean-boot.

To get back to normal version: 

From a shell session run cs foundweekends/giter8.