Set Up Custom Fields

This guide walks you through creating custom fields to collect additional information from customers during checkout.

Prerequisites

You have webhooks set up to receive custom field data

Create a Custom Field

Open the Dashboard

Go to Fungies Dashboard → Products → Game Assets

Select a Project

Click Add project to create a new one, or edit an existing project

Add a Custom Field

In the project form, scroll to Custom Fields and click Add field

Configure the Field

Choose a field type and configure its settings (see below)

Save

Click Save to apply your changes

Custom fields apply to all products within a project. Customers must fill in all custom fields to complete checkout.

Field Types

Text Field

A free-form text input for collecting strings like usernames, IDs, or notes.

Setting	Description
Label	Field label shown to customers (e.g., “Player ID”)
Placeholder	Hint text shown in the empty field
Regex	Optional pattern validation (e.g., `^[a-zA-Z0-9]{3,20}$`)
Validation URL	Optional API endpoint for custom validation

Common uses:

Player IDs / Usernames
Email addresses
External account identifiers
Custom notes or messages

Selection Field

A dropdown menu where customers choose from predefined options.

Setting	Description
Label	Field label shown to customers (e.g., “Select Server”)
Options	List of choices (minimum 1 required)

Common uses:

Game server selection
Region preference
Product variants or configurations

Example Configurations

Player ID Field

Label: Player ID
Placeholder: Enter your in-game player ID
Regex: ^[a-zA-Z0-9_]{3,32}$

This accepts alphanumeric player IDs between 3 and 32 characters.

Server Selection Field

Label: Select Your Server
Options:
  - US East
  - US West  
  - EU Central
  - Asia Pacific

Customers select which server should receive their purchased items.

Discord Username Field

Label: Discord Username
Placeholder: username#1234
Regex: ^.{3,32}#[0-9]{4}$

Validates the classic Discord username format.

Receiving Custom Field Data

When a customer completes a purchase, the custom field data is included on each line item, under data.items[].customFields — not at the top level of the event:

{
  "id": "evt_123e4567-e89b-12d3-a456-426614174000",
  "type": "payment_success",
  "data": {
    "items": [
      {
        "object": "item",
        "id": "itm_abc123",
        "name": "Legendary Sword",
        "customFields": {
          "playerId": "Player_12345",
          "server": "US East"
        }
      }
    ]
  }
}

Your webhook handler can extract this data from each item and use it to fulfill the order in your system. See the Event object reference for the full payload shape.

customFields is only populated for keys that exactly match a field’s Key. The Key you set in Add a Custom Field above is the literal property name that shows up under customFields in the webhook payload. Any value submitted at checkout whose key doesn’t match a defined field’s Key character-for-character (case-sensitive) is silently dropped — no error is raised, on either your side or ours.If customFields shows up empty or missing values:

Confirm the field is actually defined on the product (or project) being purchased — fields don’t apply store-wide, only to the project/product they’re configured on.
Confirm the key your checkout flow sends matches the field’s Key exactly.
Double-check you’re reading data.items[].customFields, not data.customFields — it’s nested per line item.

Best Practices

Keep it minimal. Only ask for information you actually need. More fields = more friction = lower conversion rates.

Use clear, descriptive labels that customers understand
Add placeholder text showing the expected format
Use regex validation to catch errors early
Consider using selection fields when there’s a fixed set of options

Next Steps

Add Validation Rules

Learn how to validate customer input with regex patterns or your own API

​Prerequisites

​Create a Custom Field

​Field Types

​Text Field

​Selection Field

​Example Configurations

​Player ID Field

​Server Selection Field

​Discord Username Field

​Receiving Custom Field Data

​Best Practices

​Next Steps

Add Validation Rules

Prerequisites

Create a Custom Field

Field Types

Text Field

Selection Field

Example Configurations

Player ID Field

Server Selection Field

Discord Username Field

Receiving Custom Field Data

Best Practices

Next Steps