Go Library API Reference

The modelsdk-go library provides programmatic access to Mendix projects from Go code. This is the underlying library that powers mxcli.

Installation

go get github.com/mendixlabs/mxcli

Quick Start

Reading a Project

package main

import (
    "fmt"
    "github.com/mendixlabs/mxcli"
)

func main() {
    // open a Mendix project
    reader, err := modelsdk.Open("/path/to/MyApp.mpr")
    if err != nil {
        panic(err)
    }
    defer reader.Close()

    // list all modules
    modules, _ := reader.ListModules()
    for _, m := range modules {
        fmt.Printf("module: %s\n", m.Name)
    }

    // get domain model for a module
    dm, _ := reader.GetDomainModel(modules[0].ID)
    for _, entity := range dm.Entities {
        fmt.Printf("  entity: %s\n", entity.Name)
        for _, attr := range entity.Attributes {
            fmt.Printf("    - %s: %s\n", attr.Name, attr.Type.GetTypeName())
        }
    }

    // list microflows
    microflows, _ := reader.ListMicroflows()
    fmt.Printf("Total microflows: %d\n", len(microflows))

    // list pages
    pages, _ := reader.ListPages()
    fmt.Printf("Total pages: %d\n", len(pages))
}

Modifying a Project

package main

import (
    "github.com/mendixlabs/mxcli"
)

func main() {
    // open for writing
    writer, err := modelsdk.OpenForWriting("/path/to/MyApp.mpr")
    if err != nil {
        panic(err)
    }
    defer writer.Close()

    reader := writer.Reader()
    modules, _ := reader.ListModules()
    dm, _ := reader.GetDomainModel(modules[0].ID)

    // create a new entity
    customer := modelsdk.NewEntity("Customer")
    writer.CreateEntity(dm.ID, customer)

    // add attributes
    writer.AddAttribute(dm.ID, customer.ID, modelsdk.NewStringAttribute("Name", 200))
    writer.AddAttribute(dm.ID, customer.ID, modelsdk.NewStringAttribute("Email", 254))
    writer.AddAttribute(dm.ID, customer.ID, modelsdk.NewBooleanAttribute("IsActive"))
    writer.AddAttribute(dm.ID, customer.ID, modelsdk.NewDateTimeAttribute("CreatedDate", true))

    // create another entity
    order := modelsdk.NewEntity("Order")
    writer.CreateEntity(dm.ID, order)

    // create an association
    assoc := modelsdk.NewAssociation("Customer_Order", customer.ID, order.ID)
    writer.CreateAssociation(dm.ID, assoc)
}

High-Level Fluent API

The api/ package provides a simplified, fluent API inspired by the Mendix Web Extensibility Model API:

package main

import (
    "github.com/mendixlabs/mxcli/api"
    "github.com/mendixlabs/mxcli/sdk/mpr"
)

func main() {
    writer, err := mpr.OpenForWriting("/path/to/MyApp.mpr")
    if err != nil {
        panic(err)
    }
    defer writer.Close()

    // create the high-level api
    modelAPI := api.New(writer)

    // set the current module context
    module, _ := modelAPI.Modules.GetModule("MyModule")
    modelAPI.SetModule(module)

    // create entity with fluent builder
    customer, _ := modelAPI.DomainModels.CreateEntity("Customer").
        persistent().
        WithStringAttribute("Name", 100).
        WithStringAttribute("Email", 254).
        WithIntegerAttribute("Age").
        WithBooleanAttribute("IsActive").
        WithDateTimeAttribute("CreatedDate", true).
        build()

    // create another entity
    order, _ := modelAPI.DomainModels.CreateEntity("Order").
        persistent().
        WithDecimalAttribute("TotalAmount").
        WithDateTimeAttribute("OrderDate", true).
        build()

    // create association between entities
    _, _ = modelAPI.DomainModels.CreateAssociation("Customer_Orders").
        from("Customer").
        to("Order").
        OneToMany().
        build()

    // create enumeration
    _, _ = modelAPI.Enumerations.CreateEnumeration("OrderStatus").
        WithValue("Pending", "Pending").
        WithValue("Processing", "Processing").
        WithValue("Completed", "Completed").
        WithValue("Cancelled", "Cancelled").
        build()

    // create microflow
    _, _ = modelAPI.Microflows.CreateMicroflow("ACT_ProcessOrder").
        WithParameter("Order", "MyModule.Order").
        WithStringParameter("message").
        ReturnsBoolean().
        build()
}

API Reference

Core Types

Type	Description
`modelsdk.ID`	Unique identifier for model elements (UUID)
`modelsdk.Module`	Represents a Mendix module
`modelsdk.Project`	Represents a Mendix project
`modelsdk.DomainModel`	Contains entities and associations
`modelsdk.Entity`	An entity in the domain model
`modelsdk.Attribute`	An attribute of an entity
`modelsdk.Association`	A relationship between entities
`modelsdk.Microflow`	A microflow (server-side logic)
`modelsdk.Nanoflow`	A nanoflow (client-side logic)
`modelsdk.Page`	A page in the UI
`modelsdk.Layout`	A page layout template

Reader Methods

// open a project
reader, _ := modelsdk.Open("path/to/project.mpr")
defer reader.Close()

// Metadata
reader.Path()                    // get file path
reader.Version()                 // get MPR version (1 or 2)
reader.GetMendixVersion()        // get Mendix Studio Pro version

// modules
reader.ListModules()             // list all modules
reader.GetModule(id)             // get module by ID
reader.GetModuleByName(name)     // get module by name

// Domain models
reader.ListDomainModels()        // list all domain models
reader.GetDomainModel(moduleID)  // get domain model for module

// microflows & nanoflows
reader.ListMicroflows()          // list all microflows
reader.GetMicroflow(id)          // get microflow by ID
reader.ListNanoflows()           // list all nanoflows
reader.GetNanoflow(id)           // get nanoflow by ID

// pages & layouts
reader.ListPages()               // list all pages
reader.GetPage(id)               // get page by ID
reader.ListLayouts()             // list all layouts
reader.GetLayout(id)             // get layout by ID

// Other
reader.ListEnumerations()        // list all enumerations
reader.ListConstants()           // list all constants
reader.ListScheduledEvents()     // list all scheduled events
reader.ExportJSON()              // export entire model as json

Writer Methods

// open for writing
writer, _ := modelsdk.OpenForWriting("path/to/project.mpr")
defer writer.Close()

// access the reader
reader := writer.Reader()

// modules
writer.CreateModule(module)
writer.UpdateModule(module)
writer.DeleteModule(id)

// entities
writer.CreateEntity(domainModelID, entity)
writer.UpdateEntity(domainModelID, entity)
writer.DeleteEntity(domainModelID, entityID)

// attributes
writer.AddAttribute(domainModelID, entityID, attribute)

// associations
writer.CreateAssociation(domainModelID, association)
writer.DeleteAssociation(domainModelID, associationID)

// microflows & nanoflows
writer.CreateMicroflow(microflow)
writer.UpdateMicroflow(microflow)
writer.DeleteMicroflow(id)
writer.CreateNanoflow(nanoflow)
writer.UpdateNanoflow(nanoflow)
writer.DeleteNanoflow(id)

// pages & layouts
writer.CreatePage(page)
writer.UpdatePage(page)
writer.DeletePage(id)
writer.CreateLayout(layout)
writer.UpdateLayout(layout)
writer.DeleteLayout(id)

// Other
writer.CreateEnumeration(enumeration)
writer.CreateConstant(constant)

Helper Functions

// create attributes
modelsdk.NewStringAttribute(name, length)
modelsdk.NewIntegerAttribute(name)
modelsdk.NewDecimalAttribute(name)
modelsdk.NewBooleanAttribute(name)
modelsdk.NewDateTimeAttribute(name, localize)
modelsdk.NewEnumerationAttribute(name, enumID)

// create entities
modelsdk.NewEntity(name)                 // Persistable entity
modelsdk.NewNonPersistableEntity(name)   // non-persistable entity

// create associations
modelsdk.NewAssociation(name, parentID, childID)      // reference (1:N)
modelsdk.NewReferenceSetAssociation(name, p, c)       // reference set (M:N)

// create flows
modelsdk.NewMicroflow(name)
modelsdk.NewNanoflow(name)

// create pages
modelsdk.NewPage(name)

// generate IDs
modelsdk.GenerateID()

Fluent API Namespaces

Namespace	Description
`modelAPI.DomainModels`	Create/modify entities, attributes, associations
`modelAPI.Enumerations`	Create/modify enumerations and values
`modelAPI.Microflows`	Create microflows with parameters and return types
`modelAPI.Pages`	Create pages with widgets (DataView, TextBox, etc.)
`modelAPI.Modules`	List and retrieve modules

Package Structure

github.com/mendixlabs/mxcli/
├── modelsdk.go          # Main package with convenience functions
├── model/               # Core model types (ID, module, project, etc.)
├── api/                 # High-level fluent api (builders)
│   ├── api.go           # ModelAPI entry point
│   ├── domainmodels.go  # EntityBuilder, AssociationBuilder
│   ├── enumerations.go  # EnumerationBuilder
│   ├── microflows.go    # MicroflowBuilder
│   ├── pages.go         # PageBuilder, widget builders
│   └── modules.go       # ModulesAPI
├── sdk/
│   ├── domainmodel/     # Domain model types (entity, attribute, association)
│   ├── microflows/      # microflow and nanoflow types
│   ├── pages/           # page, layout, and widget types
│   └── mpr/             # MPR file reader and writer
└── examples/            # Example applications

MPR File Format

Mendix projects are stored in .mpr files which are SQLite databases containing BSON-encoded model elements.

MPR v1 (Mendix < 10.18)

Single .mpr file containing all model data
Documents stored as BSON blobs in SQLite

MPR v2 (Mendix >= 10.18)

.mpr file contains references and metadata
mprcontents/ folder contains individual document files
Better for Git versioning and large projects

The library automatically detects and handles both formats.

Model Structure

project
├── modules
│   ├── Domain model
│   │   ├── entities
│   │   │   ├── attributes
│   │   │   ├── Indexes
│   │   │   ├── access rules
│   │   │   ├── validation rules
│   │   │   └── event Handlers
│   │   ├── associations
│   │   └── Annotations
│   ├── microflows
│   │   ├── parameters
│   │   └── Activities & Flows
│   ├── nanoflows
│   ├── pages
│   │   ├── widgets
│   │   └── data Sources
│   ├── layouts
│   ├── snippets
│   ├── enumerations
│   ├── constants
│   ├── Scheduled events
│   └── java actions
└── project Documents

Examples

Read Project Information

cd examples/read_project
go run main.go /path/to/MyApp.mpr

Modify Project

cd examples/modify_project
go run main.go /path/to/MyApp.mpr

Warning: Always backup your .mpr file before modifying it!

Comparison with Official SDK

Feature	Mendix Model SDK (TypeScript)	modelsdk-go
Language	TypeScript/JavaScript	Go
Runtime	Node.js	Native binary
Cloud Required	Yes (Platform API)	No
Local Files	No	Yes
Real-time Collaboration	Yes	No
Read Operations	Yes	Yes
Write Operations	Yes	Yes
Type Safety	Yes (TypeScript)	Yes (Go)
CLI Tool	No	Yes (mxcli)
SQL-like DSL	No	Yes (MDL)

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Go Library API Reference

Installation

Quick Start

Reading a Project

Modifying a Project

High-Level Fluent API

API Reference

Core Types

Reader Methods

Writer Methods

Helper Functions

Fluent API Namespaces

Package Structure

MPR File Format

MPR v1 (Mendix < 10.18)

MPR v2 (Mendix >= 10.18)

Model Structure

Examples

Read Project Information

Modify Project

Comparison with Official SDK

Resources

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GO_LIBRARY.md

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Go Library API Reference

Installation

Quick Start

Reading a Project

Modifying a Project

High-Level Fluent API

API Reference

Core Types

Reader Methods

Writer Methods

Helper Functions

Fluent API Namespaces

Package Structure

MPR File Format

MPR v1 (Mendix < 10.18)

MPR v2 (Mendix >= 10.18)

Model Structure

Examples

Read Project Information

Modify Project

Comparison with Official SDK

Resources