SPMCP — Mendix Studio Pro MCP Extension

A Mendix Studio Pro extension that exposes the full modeling API through a Model Context Protocol (MCP) server over HTTP/SSE. Enables AI tools (Claude, Cursor, Copilot, etc.) to read, create, modify, and manage Mendix application models programmatically.

84 tools across domain modeling, microflows, pages, security, workflows, and more.

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Installation (Studio Pro 10.24.13)

Step 1 — Import the module

1. Download dist/SPMCP.mpk
2. In Studio Pro, go to App > Import Module Package and select SPMCP.mpk
3. Accept the import — the SPMCP module will appear in your project

Step 2 — Enable extension development

Extensions require the --enable-extension-development flag when launching Studio Pro.

Option A — Shortcut (recommended): Right-click your Studio Pro shortcut > Properties > append the flag to the Target field:

"C:\Users\...\studiopro.exe" --enable-extension-development

Option B — Command line:

studiopro.exe "YourProject.mpr" --enable-extension-development

Step 3 — Start the MCP server

Open the SPMCP dockable pane in Studio Pro (View menu or toolbar). The MCP server starts automatically when the pane opens.

Verify it's running:

http://localhost:3001/health

Step 4 — Connect your AI tool

Transport	Endpoint	Description
Streamable HTTP	http://localhost:3001/mcp	Primary (MCP spec 2025-03-26)
SSE (legacy)	http://localhost:3001/sse	Legacy SSE transport (MCP spec 2024-11-05)
Health	http://localhost:3001/health	Health check
Metadata	http://localhost:3001/.well-known/mcp	Server capabilities

Default port is 3001. Change it via the settings button in the SPMCP pane.

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Tool Reference (84 Tools)

Domain Model — CRUD (15 tools)

Tool	Description
read_domain_model	Read full domain model: entities, attributes, associations, generalizations, event handlers
create_entity	Create entity with attributes. Supports 9 types: persistent, non-persistent, filedocument, image, audit trail variants
create_association	Create association between entities. Cross-module supported
create_multiple_entities	Bulk entity creation with per-entity module targeting
create_multiple_associations	Bulk association creation with cross-module support
create_domain_model_from_schema	Create complete domain model from JSON schema
delete_model_element	Delete entity, attribute, association, or microflow
add_attribute	Add attribute to existing entity (all types including Binary, HashedString, Long)
set_calculated_attribute	Make attribute calculated via microflow
set_entity_generalization	Set entity inheritance (cross-module)
remove_entity_generalization	Remove entity inheritance
add_event_handler	Add before/after event handler (create/commit/delete/rollback)
configure_system_attributes	Toggle system attrs: HasCreatedDate, HasChangedDate, HasOwner, HasChangedBy
diagnose_associations	Troubleshoot association creation issues
arrange_domain_model	Smart layout of entities on domain model canvas

Domain Model — Modify & Rename (11 tools)

Tool	Description
update_attribute	Change type, length, default value, or enumeration of existing attribute
update_association	Change owner, type, delete behavior of existing association
rename_entity	Rename entity (auto-updates all references)
rename_attribute	Rename attribute (auto-updates all references)
rename_association	Rename association (auto-updates all references)
rename_document	Rename any document (microflow, page, constant, etc.)
rename_module	Rename a module (auto-updates qualified references)
rename_enumeration_value	Rename enumeration value
set_documentation	Set documentation on entity, attribute, association, or domain model
read_attribute_details	Detailed attribute info: type details, validation, access rights
query_associations	Query associations by module, entity pair, or direction

Microflows (14 tools)

Tool	Description
list_microflows	List microflows with metadata
create_microflow	Create microflow with parameters and return type
read_microflow_details	Full microflow inspection: parameters, return type, all activities
create_microflow_activities	Create activity sequences (create_object, change_object, retrieve, commit, delete, show_message, close_page)
update_microflow	Update return type, return variable, URL
modify_microflow_activity	Modify existing activity properties by position
insert_before_activity	Insert activity before a specific position
check_variable_name	Check if variable name is available in a microflow
set_microflow_url	Expose microflow as REST endpoint
list_rules	List validation rules across modules
exclude_document	Mark document as excluded/included
copy_model_element	Deep-copy entity, microflow, constant, or enumeration
list_java_actions	List Java actions with parameters
validate_name	Validate candidate name for model elements

Constants & Enumerations (7 tools)

Tool	Description
create_constant	Create constant (string/integer/boolean/decimal/datetime)
list_constants	List constants across modules
update_constant	Modify constant default value or exposed_to_client flag
configure_constant_values	Set constant value overrides per run configuration
create_enumeration	Create enumeration with values and captions
list_enumerations	List enumerations with all values
update_enumeration	Add/remove enumeration values

Pages (4 tools)

Tool	Description
list_pages	List pages with widget count, layout, parameters, documentation
read_page_details	Full page inspection: widget tree, data sources, parameters, actions
generate_overview_pages	Generate CRUD overview pages for entities
delete_document	Delete page, microflow, or any document from module

Nanoflows (2 tools)

Tool	Description
list_nanoflows	List nanoflows with return type, activity count, parameters
read_nanoflow_details	Full nanoflow inspection: parameters, activities, actions

Workflows (2 tools)

Tool	Description
list_workflows	List workflows with context entity, activity count, documentation
read_workflow_details	Full workflow inspection: activities (UserTasks, Decisions, SystemActivities), flows, security

Security (4 tools)

Tool	Description
read_security_info	Project/module security: user roles, module roles, password policy
read_entity_access_rules	Entity access rules: CRUD permissions, XPath constraints, member rights
read_microflow_security	Microflow execution permissions by role
audit_security	Gap analysis: entities without access rules, overly permissive rules

Project & Settings (7 tools)

Tool	Description
read_project_info	Project overview: all modules with entity/microflow/page counts
read_runtime_settings	Read after-startup, before-shutdown, health-check microflows
set_runtime_settings	Assign/clear runtime hook microflows
read_configurations	List run configurations with settings and constant overrides
set_configuration	Create/update run configuration
read_version_control	Version control status: branch, commit, VC type
manage_navigation	Add pages to responsive web navigation

Module & Folder Management (4 tools)

Tool	Description
list_modules	List all modules in the project with metadata (name, source, entity count)
create_module	Create new module
manage_folders	Create, list, or move documents between folders
sync_filesystem	Import changes from JavaScript actions, widgets, external files

Data & Diagnostics (8 tools)

Tool	Description
save_data	Generate sample data with entity relationships
generate_sample_data	Auto-generate realistic sample data from domain model schema
read_sample_data	Read previously saved sample data
setup_data_import	Wire up sample data import pipeline with Java action
check_model	Validate model for broken generalizations, missing handlers, etc.
check_project_errors	Run mx.exe consistency check (CE error codes)
get_studio_pro_logs	Read Studio Pro and MCP extension logs
get_last_error	Get last error details with stack trace

Meta & Discovery (6 tools)

Tool	Description
list_available_tools	List all 84 tools with capabilities
debug_info	Comprehensive domain model debug info with usage examples
list_scheduled_events	List scheduled events with interval and status
list_rest_services	List published REST services with paths and authentication
query_model_elements	Generic metamodel escape-hatch: query any type by name
analyze_project_patterns	Analyze naming conventions, structural patterns, and best practices across modules. Optionally writes a skill file to .claude/skills/ so future AI sessions follow the project's established conventions

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MCP Endpoints

http://localhost:3001/sse       SSE stream (connect here from Claude/Cursor)
http://localhost:3001/message   POST endpoint for tool calls
http://localhost:3001/health    Server health check

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Setting Up Sample Data Import (After Startup)

The SPMCP module includes a Java action (SPMCP.InsertDataFromJSON) that loads sample data into your app on startup. After generating sample data via the generate_sample_data MCP tool, wire it up as follows:

Using the MCP tool (recommended)

Call generate_sample_data — it auto-creates the ASu_LoadSampleData microflow and wires it to After Startup in one call:

{
  "name": "generate_sample_data",
  "arguments": {
    "module_names": ["MyFirstModule"],
    "auto_setup": true
  }
}

If an After Startup microflow already exists, use force_after_startup:

{
  "name": "setup_data_import",
  "arguments": {
    "force_after_startup": true
  }
}

Manual wiring

1. In Studio Pro, open App Settings > Runtime tab
2. Set After startup to SPMCP.ASu_LoadSampleData
3. Run the app — sample data loads on first startup and the JSON file is deleted on success

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Troubleshooting

Issue	Solution
Extension not visible	Ensure --enable-extension-development flag is set on Studio Pro launch
Server won't start	Open the SPMCP dockable pane in Studio Pro (View menu)
Port conflict	Server auto-finds next available port from 3001
Connection refused	Check http://localhost:3001/health and Windows Firewall
Tool errors	Use get_last_error for stack traces, check_project_errors for CE codes
Sample data not loading	Verify SPMCP.ASu_LoadSampleData is set as After Startup in App Settings

Logs

• MCP debug log: {MendixProjectPath}/resources/mcp_debug.log
• Studio Pro logs: accessible via get_studio_pro_logs tool

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Known Limitations

• Pages: Only overview page generation. No widget-level creation/editing via Extensions API
• Nanoflows: Read-only introspection. No creation API
• Workflows: Read-only introspection. No creation/editing API
• Log Message Activity: CreateLogMessageActivity does not exist in the Extensions API
• retrieve and change_object in create_microflow_activities may produce wrong action type — use modify_microflow_activity to correct after creation

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License

Experimental — provided as-is for research and development purposes.