Add Multi File Upload

Audience: Low-code Engineers

Skill Prerequisites: Forms, Tokens

Adds an upload field for several files to a Dynamic Field Container when the form loads. It works like a Multi File Upload field placed in the form builder, including actions that run for each uploaded file.

See Dynamic Fields for how dynamic fields work and how to set up the container.

Typical Use Cases

• Collect photos or documents for each item in a list
• Add a place for attachments only when it's needed

Don't use it to

• Upload just one file. Use Add Single File Upload instead.

Related Actions

Action Name	Description
Add Single File Upload	Adds an upload field for one file.
Pack folder	Zips the uploaded files after submit.

Input Parameter Reference

This action has the same parameters as Add Single File Upload, plus:

Parameter	Description	Supports Tokens	Default	Required
For Each File	Actions that run once for each uploaded file when the form is submitted. Inside them, tokens such as [FileName] (the name without extension), [FileNameAndExtension], [FileId], [RelativeUrl], [FilePath], [FileSize] and [MimeType] describe the current file.	No	empty	No

caution

Use Folder Path mode when you use For Each File. With Folder ID mode, the per-file actions can't find the uploaded files.

Output Parameters Reference

Parameter	Description
Field ID Token Name	Optional. Token that receives the cleaned field ID. If empty, the ID is saved in [<FieldId>:Name].

When the form is submitted, the uploaded files are described by the same tokens as a Multi File Upload field, for example [<FieldId>:Count], [<FieldId>:FileIds] and [<FieldId>:Filenames] (separated by semicolons). See Multi File Upload for the full list.

Examples

tip

To understand how to use the below examples, please see Running Examples.

1. Add a photo upload

Add this action to the form's On PreInit or On Init actions. It adds a field to the ExtraFields container for JPG and PNG photos up to 10 MB each, saved in the Photos folder.

{
    "Title": "Add Multi File Upload",
    "ActionType": "AddMultiFileUpload",
    "Description": "Add the photo upload",
    "Condition": null,
    "Parameters": {
        "ContainerId": "ExtraFields",
        "FieldId": "Photos",
        "FieldName": "Photos",
        "FolderInputMode": {
            "Expression": "",
            "Value": "FolderPath",
            "IsExpression": false,
            "Parameters": {}
        },
        "Folder": {
            "Expression": "",
            "Value": "/Photos",
            "IsExpression": false,
            "Parameters": {}
        },
        "Pattern": "",
        "FileExt": "jpg,jpeg,png",
        "FileLimit": "10",
        "MaxSizeInError": true,
        "Duplicates": {
            "Expression": "",
            "Value": "Rename",
            "IsExpression": false,
            "Parameters": {}
        },
        "Actions": [],
        "IsRequired": "false",
        "FieldIdTokenName": ""
    }
}

Revised 09/25/2026