# MDriven release notes — September 2026

**URL:** <https://community.mdriven.net/t/mdriven-release-notes-september-2026/63>\
**Category:** Announcements\
**Tags:** release-notes\
**Created:** [October 25, 2026, 11:18am UTC](https://community.mdriven.net/t/mdriven-release-notes-september-2026/63 "2026-10-25T11:18:49Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![mdriven\_updates](https://community.mdriven.net/letter_avatar_proxy/v4/letter/m/b19c9b/32.png) [@mdriven\_updates](https://community.mdriven.net/u/mdriven_updates)\
**Post date:** [October 25, 2026, 11:18am UTC](https://community.mdriven.net/t/mdriven-release-notes-september-2026/63/1 "2026-10-25T11:18:50Z")

</div>

### Designer

September development focused on expanding REST GET payload controls, introducing IntendedPurpose categorization for ViewModels, enhancing MCP server capabilities, and refining editor interaction mechanics.

- **REST GET Strategy & Payload Controls:** Fully extended the BYTEARRAYCONTENT and STRINGCONTENT strategy to REST GET endpoints, allowing fine-grained control over return data; combined with FileName and ContentType columns, any string or stream can now be downloaded to any target in any format (with STRINGCONTENT defaulting to UTF-8), alongside a major refactoring of special ViewModel column names into centralized constants.
- **ViewModel Intended Purpose:** ViewModels can now declare an IntendedPurpose metadata property, enabling automatic category sorting and proactive warnings when ViewModels are utilized outside their designated purpose.
- **MCP & AI Tooling:** Extended the Designer’s built-in MCPServer with MetaModelMetaInfo, wiki search, and lookup functionality based on real-world usage scenarios; integrated a DeepSeek test harness to expose high-level ViewModel and Vibe functions.
- **UI & Tree Editor Fixes:** Resolved drag-and-drop timing and leftover artifact issues in the ViewModel tree, fixed focus-loss keystroke handling in the OCL editor, registered application icons under CurrentUser to eliminate admin privilege requirements, and fixed a Visual Studio model-switching bug that broke model saving.

### Framework

Framework updates prioritized type evaluation safety, REST response handling, WPF layout rendering, and GraphAPI enhancements.

#### REST & Content Handling

- Enhanced REST GET support for BYTEARRAYCONTENT and STRINGCONTENT strategy with FileName and ContentType column bindings across runtime targets.
- Fixed an issue where sending a RestPost without an explicit ID failed to return the expected vRestVerb.

#### Type Safety & CodeGen

- Resolved runtime exceptions during string-to-enum comparisons by automatically coercing enums via ToString prior to comparison.
- Fixed CodeGen enum serialization issues where ToString operators incorrectly returned numeric values instead of the enum value name.
- Corrected VMClass.CanExecuteAction logic to properly verify the existence of explicit read-only columns (GetExplicitColumnFor\_ReadOnly).

#### UI Layout & Integration

- **WPF Grid & Blob Rendering:** Fixed WPF grid measurement issues that caused labels and buttons to clip due to pixel grid sizing, resolved missing WPF design-time DataGrid columns, and fixed static SVG/blob rendering discrepancies between WPF and Turnkey.
- **SysDebugger & GraphAPI:** Enabled selfVM usage in SysDebugger action expressions to allow direct calls like selfVM.Save; updated SysGraphAPI.UploadToFolderWithDriveIdAndId to set WebUrl and improved error messages for missing SysUser configurations.

### Turnkey

Turnkey updates focused on REST payload delivery parity and REST POST verb responses.

- **REST GET Parity:** Implemented support for the updated BYTEARRAYCONTENT and STRINGCONTENT download strategy, allowing custom stream and string downloads using FileName and ContentType columns.
- **REST POST Fixes:** Fixed an issue where RestPost requests submitted without an ID failed to populate and return the vRestVerb state properly.

### Server

- **Ecosystem Alignment:** Modernized internal type names and updated core system references across server assemblies to ensure compatibility with .NET 10 standards.

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Full release notes: [ReleaseNotes:ReleaseNotes - MDrivenWiki](https://wiki.mdriven.net/index.php/ReleaseNotes:ReleaseNotes#september-2026)