Kappa is a command line tool. The basic command format is:

kappa [options] <command> [optional command args]

Available options are:

  • –config <config_file> to specify where to find the kappa config file. The default is to look in kappa.yml.
  • –env <environment> to specify which environment in your config file you are using. The default is dev.
  • –debug/–no-debug to turn on/off the debug logging.
  • –help to access command line help.

And command is one of:

  • deploy
  • delete
  • invoke
  • tag
  • tail
  • event_sources
  • status

Details of each command are provided below.


The deploy command does whatever is required to deploy the current version of your Lambda function such as creating/updating policies and roles, creating or updating the function itself, and adding any event sources specified in your config file.

When the command is run the first time, it creates all of the relevant resources required. On subsequent invocations, it will attempt to determine what, if anything, has changed in the project and only update those resources.


The delete command deletes the Lambda function, remove any event sources, delete the IAM policy and role.


The invoke command makes a synchronous call to your Lambda function, passing test data and display the resulting log data and any response returned from your Lambda function.

The invoke command takes one positional argument, the data_file. This should be the path to a JSON data file that will be sent to the function as data.


The tag command tags the current version of the Lambda function with a symbolic tag. In Lambda terms, this creates an alias.

The tag command requires two additional positional arguments:

  • name - the name of tag or alias
  • description - the description of the alias


The tail command displays the most recent log events for the function (remember that it can take several minutes before log events are available from CloudWatch)


The test command provides a way to run unit tests of code in your Lambda function. By default, it uses the nose Python testrunner but this can be overridden my specifying an alternative value using the unit_test_runner attribute in the kappa config file.

When using nose, it expects to find standard Python unit tests in the _tests/unit directory of your project. It will then run those tests in an environment that also makes any python modules in your _src directory available to the tests.


The event_sources command provides access the commands available for dealing with event sources. This command takes an additional positional argument, command.

  • command - the command to run (list|enable|disable)


The status command displays summary information about functions, stacks, and event sources related to your project.