Although Dynamos usually run along an OTP application, they can also be defined in a single file, useful for examples or scripting something quick. The smallest single file Dynamo can be defined as follow:

defmodule HelloWorld do
  use Dynamo
  use Dynamo.Router

  config :server, port: 3030

  get "/" do
    conn.resp_body("Hello World!")
  end
end

HelloWorld.start_link
HelloWorld.run

The example above defines a module HelloWorld which is a Dynamo and a Dynamo.Router. Then we proceed to define the port and a default route.

After the module is defined, we start the supervisor tree with HelloWorld.start_link and run the Dynamo with HelloWorld.run.

When using single file Dynamos, some features like code reloading does not work. So they may as well be disabled too by adding:

config :dynamo, compile_on_demand: false

For a ready to use example, check examples/hello_world.exs.