# cuerdo v0.4.0 - Table of Contents > Arazzo workflow runner ## Pages - Dev - [README](readme.md) - [Changelog](changelog.md) ## Modules - [Cuerdo](Cuerdo.md): Cuerdo is an [Arazzo](https://spec.openapis.org/arazzo/v1.1.0) workflow runner and automatic property-based testing tool written in Elixir. - Arazzo - [Cuerdo.Arazzo](Cuerdo.Arazzo.md): Arazzo workflows runner and validation. - [Cuerdo.Arazzo.Context](Cuerdo.Arazzo.Context.md): Internal Arazzo Context. Stores workflows and steps inputs/outputs, request/response, etc. - [Cuerdo.Arazzo.Context.APICalls](Cuerdo.Arazzo.Context.APICalls.md): The request and response of each step - ArazzoCase - [Cuerdo.ArazzoCase](Cuerdo.ArazzoCase.md): Provides an `ExUnit.CaseTemplate` for automatically generating tests from Arazzo workflows. - CLI - [Cuerdo.CLI](Cuerdo.CLI.md): CLI for automated test runner - Exceptions - [Cuerdo.Errors.ExecutionError](Cuerdo.Errors.ExecutionError.md): Error structure that wraps any raised or returned error during the execution of an Arazzo workflow/step