Building Custom Functions in Xano

Before continuing, make sure you’re familiar with:

Building Custom Functions in Xano

Custom Functions are a way to build reusable logic that you can utilize in other workflows. They allow you to build a set of steps once, use them in multiple places, and maintain them in one place. Custom Functions in Xano are built in three parts:

Inputs — Inputs are the data that the Custom Function will accept. For example, name and email.
Logic — The logic is the logic that will be executed when the Custom Function is called. For example, retrieving a record from your database or calculating a user’s age.
Response — The response is the data that the Custom Function will return. For our user_list Custom Function, it might return a list of users, or a single user.

Custom Function Folders

You can organize your Custom Functions into folders for better organization by adding a folder name to the Custom Function name — for example, utilities/user_list instead of just user_list. You can select Move functions to move your Custom Functions into a folder, and Add Folder to add a new folder.

Creating a new Custom Function

From the sidebar, click Functions or hover over it and click to create a new function immediately.

Clicking the + Add Function button will open a panel that allows you to create a new Custom Function. You’ll be asked to provide some basic information about your Custom Function before continuing.

Parameter	Description
Name	The name of the Custom Function.
Description	A description of the Custom Function.
Folder Path	The folder path for the Custom Function; this is optional and you don’t need to use a folder if you prefer.
Tags	Tags for organization.
Request History	The request history settings for the Custom Function.

You can build Custom Functions in Xano in three different ways. Choose the one that best fits your needs. You can switch between them at any time.

Canvas View
Function Stack
XanoScript

The Canvas View

The canvas view is a visual representation of your custom function in a node-based format. If you’re new to the canvas view, review the Canvas View basics first.

Add Inputs to define what your custom function accepts

Learn how to work with Inputs

Inputs define the data your custom function expects. Learn how to add and configure them.

Build your logic in the Function Logic or Canvas View

Learn how to work with Functions

Functions define the behavior of your custom function. Add and arrange functions to process inputs and fetch data.

Define what your custom function returns with the Response

Learn how to configure Responses

Control exactly what data your custom function sends back.

custom-functions-20251013-183546 — Here's an example of a basic custom function in the canvas view

A basic custom function in XanoScript has three parts — inputs, functions, and response — just like in the visual builder:

Example of a basic custom function in XanoScript

function utilities/format_timestamp {
  description = "Makes a timestamp human readable"

  input {
    timestamp? timestamp?
  }

  stack {
    var $readable_timestamp {
      value = $input.timestamp|format_timestamp:"r":"UTC"
    }
  }

  response {
    value = $readable_timestamp
  }

  middleware = {pre: [], post: []}
}

Learn how to build custom functions in XanoScript

For more information on how to build custom functions in XanoScript, see the XanoScript custom functions documentation.

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Building Custom Functions in Xano