Getting Started with Reason Functions

Use Reason Functions to inject external services and functionality into your Integrals. Unlike Integrals, functions are meant to handle single, specific tasks only

NOTE

You need to setup your environment before creating Reason Functions

Creating Basic Reason Functions

To create an Reason Function, pass in the required parameters to the CLI command and deploy. Let's go into detail

First make sure you have the latest version by pulling remote version

reasonai api pull

Next, run this command and follow the prompts

reasonai function add

# Follow the wizard and provide the following responses
> Enter function name: # getWeatherTemperatureByCity
> Description:
#   Write a detailed description of what the function does
#   e.g Given a city name, the function returns the temperature and unit of measure for that city
> Invocation type:
#   This is how the external function will be run. Select the appropriate one and fill in its parameters
#   If your preferred method is not listed, edit the function after it is created to add it
#   e.g Rest API
> Follow the next prompts which will depend on what you selected in the previous step
> Provide mode of authentication if any, for the external resource

When done, a new Reason Function will be created under ./reason/functions/getWeatherTemperatureByCity with JSON config similar to the following:

{
  "name": "getCharacterByName",
  "description": "Gets a character by name",
  "parameters": {
    "type": "object",
    "properties": {
      "name": {
        "type": "string"
      }
    }
  },
  "invocation": {
    "type": "rest_api",
    "rest_api": {
      "url": "https://sampleapis.com/futurama/api/characters?name.first={name}"
    }
  }
}

Great! Now let's run this command to deploy the Reason Function so we can start using it:

reasonai function push

That's it. Your Reason Functions is deployed and live

Next Steps

Oh bummer, our function doesn't do anything unless it is linked to an Integrals

• You've learned how to create a Reason Functions, next look at how to link an existing function to your Integrals