Custom Functions

Build business logic once and reuse it in multiple places

Quick Summary

Custom functions are very similar to your APIs — they have inputs, a function stack, and a response. However, they can not be called externally. Instead, custom functions allow you to build something and use it in other places, while maintaining it in a centralized location.

What is a custom function?

Custom functions can be thought of as a building block for the rest of your backend. You can build a custom function just like an API endpoint, and insert that custom function into other function stacks, giving you easily reusable logic while only having to maintain it in one place. When you make a change inside of a custom function, that change is automatically in effect everywhere you have chosen to use the custom function.

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Building and Using Custom Functions

1

Access your custom functions from the left-hand menu.

2

Click to create a new custom function.

Give your custom function a name, description, tags, and choose your request history settings.

When you're done, click .

3

Build your custom function

A custom function has three sections — the same as an API endpoint.

⬇️ Inputs

The inputs are anything that a function stack needs to run. For example, a function stack that logs in a user probably needs a username or email and a password; these would be the inputs.

🔄 Function stack

This is where all of the magic happens. All of the business logic that is performed lives here.

As you add functions to your function stack, it will suggest next steps based on most popular user activity.

⬆️ Response

Once the function stack has done its job, it needs to know what to return. This lives in the Response section.

4

Insert your new custom function into other function stacks.

When you're ready to use your new custom function in other function stacks, click , choose Custom Functions from the panel that opens, and select your custom function.

You'll be able to supply data for any inputs the custom function is expecting here.

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Creating Custom Functions from Existing Function Stacks

If you have a function stack that you'd like to convert into a custom function, you can do so in one of the following ways.

1

Convert the entire stack

Click the three dots in the upper-right corner and choose Convert To Function

2

Select individual steps to convert to a function

You can select a group of steps and click to convert those steps into a custom function.

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Custom Function Settings

From the Settings panel

Name	Purpose
Name	The name of the custom function.
Description	An internal description, just for you.
Tags	Use tags to organize objects throughout your Xano workspace and find them later
Request History	Inherit Settings Use whatever is set in your workspace branch defaults Other Set specific request history settings for this function 📖 Learn more about request history
Response caching	Cache the response and redeliver it during future runs 📖 Learn more about response caching