Shard Detail

amber v0.6.2

A Crystal web framework that makes building applications fast, simple, and enjoyable. Get started with quick prototyping, less bugs, and blazing fast performance.
crystal web cohesive efficient fast framework amber amber-framework scaffolding cli web-framework

Install & Use

Add the following code to your project's shard.yml under:

dependencies to use in production
- OR -
development_dependencies to use in development

  github: amberframework/amber
  version: 0.6.2


Productivity. Performance. Happiness.

Amber makes building web applications fast, simple, and enjoyable - with fewer bugs and blazing fast performance.

Welcome to Amber

Amber is a web application framework written in Crystal inspired by Kemal, Rails, Phoenix and other popular application frameworks.

The purpose of Amber is not to create yet another framework, but to take advantage of the beautiful Crystal language capabilities and provide engineers and the Crystal community with an efficient, cohesive, well maintained web framework that embraces the language philosophies, conventions, and guidelines.

Amber borrows concepts that have already been battle tested and successful, and embraces new concepts through team and community collaboration and analysis, which also aligns with Crystal's philosophy.

Read the Docs



Latest Results 968,824.35 requests per second: 32 cores at 2.7Ghz

ubuntu@ip-172-31-0-70:~/bench⟫ wrk -d 60 -t 20 -c 1015 http://localhost:3000
Running 1m test @ http://localhost:3000
  20 threads and 1015 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     1.86ms    2.88ms  56.61ms   87.54%
    Req/Sec    48.73k     6.01k   88.40k    68.28%
  58225168 requests in 1.00m, 4.01GB read
Requests/sec: 968824.35
Transfer/sec:     68.37MB

Disclaimer: We share these benchmark results with the understanding they may vary depending on configuration and environment settings. By no means are we making any comparison claims in regards to other web application frameworks.



Ensure you have the necessary dependencies:

For Debian & Ubuntu

These are necessary to compile the CLI:

  • apt-get install build-essential libreadline-dev libsqlite3-dev libpq-dev libmysqlclient-dev libssl-dev`

Once you have these dependencies, you can build amber from source:

$ git clone
$ cd amber
$ make
$ make install
For ArchLinux & derivates
  • Install the CLI from AUR package. Dependencies are automatically installed.
  • yaourt -S amber

You should now be able to run amber in the command line.

Mac OS X

Best way to get amber on Mac OS X is via Homebrew:

$ brew install amberframework/amber/amber

Refer to this link if you don't have homebrew installed.

Amber CLI Commands

$ amber --help

Amber - Command Line Interface

  The `amber new` command creates a new Amber application with a default
  directory structure and configuration at the path you specify.

  You can specify extra command-line arguments to be used every time
  `amber new` runs in the .amber.yml configuration file in your project
  root directory

  Note that the arguments specified in the .amber.yml file does not affect the
  defaults values shown above in this help message.

  amber new [app_name] -d [pg | mysql | sqlite] -t [slang | ecr] -m [granite, crecto] --deps

  d         alias for deploy
  database  # Performs database maintenance tasks
  db        alias for database
  deploy    # Provisions server and deploys project.
  e         alias for encrypt
  encrypt   # Encrypts environment YAML file. [env | -e --editor | --noedit]
  exec      # Executes Crystal code within the application scope
  g         alias for generate
  generate  # Generate Amber classes
  n         alias for new
  new       # Generates a new Amber project
  routes    # Prints all defined application routes
  w         alias for watch
  watch     # Starts amber development server and rebuilds on file changes
  x         alias for exec

  -d, --database  # Preconfigure for selected database. Options: pg | mysql | sqlite
                  (default: pg)
  -m, --model     # Preconfigure for selected model. Options: granite | crecto
                  (default: granite)
  -t, --template  # Preconfigure for selected template engine. Options: slang | ecr
                  (default: slang)
  -h, --help      # Describe available commands and usages
  -v, --version   # Prints Amber version

  amber new ~/Code/Projects/weblog
  This generates a skeletal Amber installation in ~/Code/Projects/weblog.


amber new [app_name] -d [pg | mysql | sqlite] -t [slang | ecr] -m [granite, crecto] --deps
cd [your_app]

options: -d defaults to pg. -t defaults to slang. -m defaults to granite. --deps will run crystal deps for you.

This will generate a traditional web application:

  • /config - Application and HTTP::Handler config's goes here. The database.yml and are here.
  • /lib - Shards are installed here.
  • /public - Default location for HTML/CSS/js files. The static handler points to this directory.
  • /spec - All crystal specs go here.
  • /src - All source code goes here.


Generate scaffolding for a resource:

amber generate scaffold Post name:string body:text draft:bool

This will generate scaffolding for Post:

  • src/controllers/
  • src/models/
  • src/views/post/*
  • db/migrations/[datetimestamp]_create_post.sql
  • spec/controllers/
  • spec/models/
  • appends route to config/
  • appends navigation to src/layouts/_nav.slang

Running App Locally

To test the generated app locally:

  1. Create and migrate the database: amber db create migrate. You should see output like Migrating db, current version: 0, target: [datetimestamp]OK [datetimestamp]_create_shop.sql
  2. Run the specs: crystal spec
  3. Start your app: amber watch
  4. Then visit

Note: The amber watch command is based on Sentry to watch for any changes in your source files, recompiling automatically.

If you don't want to use Sentry, you can compile and run manually:

  1. Build the app crystal build --release src/[your_app].cr
  2. Run with ./[your_app]
  3. Visit


Questions or suggestions? Join our IRC channel #amber at or ask on our Gitter room.

Amber Philosophy H.R.T.

It's all about the community. Software development is a team sport!

It's not enough to be brilliant when you're alone in your programming lair. You are not going to change the world or delight millions of users by hiding and preparing your secret invention. We need to work with other members, we need to share our visions, divide the labor, learn from others, we need to be a team.

HUMILITY We are not the center of the universe. You're neither omniscient nor infallible. You are open to self-improvement.

RESPECT You genuinely care about others you work with. You treat them as human beings and appreciate their abilities and accomplishments.

TRUST You believe others are competent and will do the right thing, and you are OK with letting them drive when appropriate.

Code of Conduct

We have adopted the Contributor Covenant to be our CODE OF CONDUCT guidelines for Amber.

Have an Amber-based Project?

Use Amber badge Amber Framework

[![Amber Framework](](Your project url)


Contributing to Amber can be a rewarding way to learn, teach, and build experience in just about any skill you can imagine. You don’t have to become a lifelong contributor to enjoy participating in Amber.

Amber is a community effort and we want You to be part of it. Join Amber Community!

  1. Fork it (
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request

Amber Core Team


This project is licensed under the MIT License - see the LICENSE file for details


  • Inspired by Kemal, Rails, Phoenix, Hanami