Use the Untyped Model Access API Using C#

Last modified: November 17, 2025

Introduction

The Untyped Model Access API is designed for advanced users familiar with the internals of the Mendix platform. It allows access to the rich data of model elements.

For model elements, units, and property names, see the Mendix Model SDK.
Type names used by the Untyped Model Access API are available under the structureTypeName property of any model element.

All methods in the Untyped Model API are recursive to reduce the amount of API calls necessary to retrieve content.

Prerequisites

Before using the examples in this how-to:

Create a microflow named MyFirstLogic with an action
Add an entity to the domain model

Getting Started

Begin by importing the Untyped Model Access API service:

class Sample(IUntypedModelAccessService untypedModelAccessService)
{
}

Access the Model Root

Use the Untyped Model Access AP to gain access to the model Root:

class Sample2(IUntypedModelAccessService untypedModelAccessService, IModel currentApp)
{
    public IModelRoot GetUntypedModelRoot() => untypedModelAccessService.GetUntypedModel(currentApp);
}

Requesting Top-level Model Elements

To access the model elements, such as Apps and Modules, choose a starting point:

class Sample3(IUntypedModelAccessService untypedModelAccessService, IModel currentApp)
{
    public IModelUnit GetProjectData() =>
        untypedModelAccessService.GetUntypedModel(currentApp)
            .GetUnitsOfType("Projects$Project")
            .Single();

    public IModelUnit GetMyModuleData() =>
        untypedModelAccessService.GetUntypedModel(currentApp)
            .GetUnitsOfType("Projects$Module")
            .Single(unit => unit.Name == "MyFirstModule");
}

Accessing Child Elements

You can access the child elements of a model element, such as microflow actions or entities of a domain model.

Use GetElements or GetElementsOfType to analyze the element properties and implement custom validation rules.

class Sample4(IUntypedModelAccessService untypedModelAccessService, IModel currentApp)
{
    public IReadOnlyList<IModelElement> GetMicroflowActionActivities() =>
        untypedModelAccessService.GetUntypedModel(currentApp)
            .GetUnitsOfType("Projects$Module")
            .Single(unit => unit.Name == "MyFirstModule")
            .GetUnitsOfType("Microflows$Microflow")
            .Single(unit => unit.Name == "MyFirstLogic")
            .GetElementsOfType("Microflows$ActionActivity");

    public IReadOnlyList<IModelElement> GetDomainModelEntities() =>
        untypedModelAccessService.GetUntypedModel(currentApp)
            .GetUnitsOfType("Projects$Module")
            .Single(unit => unit.Name == "MyFirstModule")
            .GetUnitsOfType("DomainModels$DomainModel").Single()
            .GetElementsOfType("DomainModels$Entity");
}

Getting Model Unit's Properties

To extract data out of a model element or unit, access its properties:

class Sample5(IUntypedModelAccessService untypedModelAccessService, IModel currentApp)
{
    private IReadOnlyList<IModelProperty> GetProjectRuntimeSettingsProperties() =>
        untypedModelAccessService.GetUntypedModel(currentApp)
            .GetUnitsOfType("Settings$ProjectSettings")
            .Single()
            .GetElements()
            .Single(element => element.Type == "Settings$RuntimeSettings")
            .GetProperties();


    public string? GetAfterStartupMicroflowId() =>
        GetProjectRuntimeSettingsProperties()
            .Single(property => property.Name == "AfterStartupMicroflowId")
            .Value?
            .ToString();
}