Browse .NET News (97)

Pablo Lopes announces a free, open-source course that guides developers through modernizing a legacy ASP.NET app to .NET 10 using the GitHub Copilot modernization agent, including assessment and planning artifacts, an execution workflow, and a final deployment to Azure App Service.
Lily Ma explains why synchronous MCP tool calls break down for long-running work, and shows a practical Azure Functions + Durable Functions pattern you can use today while the MCP Tasks extension rolls out across clients and SDKs.
Ruben Rios announces a preview of Private Marketplace support in Visual Studio, aimed at organizations that need tighter control over how developers discover and install extensions for security, compliance, and governance reasons.

Visual Studio Code 1.130 (Insiders)

The Visual Studio Code Team shares the evolving release notes for VS Code 1.130 (Insiders), with links to the commit log and closed issues so developers can track what’s landing in the build as features are added.
Rachel Kang explains new Visual Studio features for working with GitHub Copilot models: pinning favorites in the model picker, comparing model capabilities (like context window size and vision support), and tracking context window and plan usage so long-running chats don’t catch you off guard.

.NET and .NET Framework July 2026 servicing releases updates

Rahul Bhandari (MSFT) and Tara Overfield recap the July 2026 servicing releases for .NET and .NET Framework, including a list of fixed security vulnerabilities (CVEs) and direct links to release notes, installers, container images, Linux package instructions, and known issues for supported .NET versions.
David Ortinau shares a progress update on moving .NET MAUI mobile apps to CoreCLR in .NET 11 Preview 6, including current performance expectations, tooling status (debugging and Hot Reload), and what developers should validate now to influence the .NET 11 GA release.

.NET 11 Preview 6 is now available!

.NET Team announces .NET 11 Preview 6 and highlights what’s new across the runtime, SDK, libraries, ASP.NET Core, .NET MAUI, C#, Entity Framework Core, F#, and container images, with links to detailed release notes and download instructions to try the preview.

Built-in Agent Skills Bring .NET and Azure Expertise into Visual Studio

Simona Liao, Wendy Breiding, and Yun Jung Choi introduce Visual Studio 18.8’s built-in Agent Skills, a set of reusable Copilot capabilities for common .NET and Azure tasks. The post explains where to find and enable skills, why they’re off by default, and highlights starter skills for API work, performance reviews, Azure deployments, and Kusto queries.
Allison announces CodeQL 2.26.0 updates for GitHub code scanning, including Kotlin 2.4.0 support, improved C# Razor Pages dataflow for SQL injection detection, new JavaScript/TypeScript system prompt injection coverage, and multiple query accuracy improvements across Go, Python, Swift, and GitHub Actions.
Mika Dumont introduces an interactive upgrade canvas in the GitHub Copilot app that lets teams track a .NET modernization end-to-end, from assessment and planning through execution, code changes, build failures, and final results, with the same upgrade workflow available in Visual Studio, VS Code, and the Copilot CLI.
Wes Steyn shows how to scale a Microsoft Agent Framework “claw” using the Agent Harness: on-demand skills (including centrally managed Foundry skills via MCP), approval-gated shell access, CodeAct for sandboxed code execution, and concurrent background agents, with runnable samples in both .NET and Python.
David Pine explains how the .NET Aspire team uses GitHub Agentic Workflows to turn merged product pull requests into SME-reviewed documentation pull requests in a separate repo, while keeping security tight through a “safe-outputs” contract and narrowly scoped GitHub App permissions.
Evan Mattson announces the 1.0 release of Microsoft Agent Framework’s orchestration patterns across both Python and .NET, explaining what’s now stable (sequential, concurrent, group chat, handoff, and magentic) and why higher-level orchestration builders matter for multi-agent apps.

Visual Studio Code 1.129 (Insiders)

The Visual Studio Code Team shares the early release notes for VS Code 1.129 (Insiders), including links to the commit log and closed issues so developers can track what’s landing as the milestone evolves.

Agent Skills for .NET Is Now Released

Sergey Menshykh announces the stable release of Agent Skills for .NET in Microsoft Agent Framework, describing an open format for packaging reusable domain expertise (instructions, resources, and scripts) that agents load on demand, plus the governance controls needed to run skills safely in production.
Nick Brady’s June 2026 digest covers the biggest Microsoft Foundry updates: Claude reaching general availability, new agent distribution into Microsoft 365 Copilot and Teams, and major improvements across Toolboxes, Routines, Memory, observability, and Foundry Local deployments.

MCP Beyond the Chat Window: Build Diagnostics in CI

Jan Krivanek and Yuliia Kovalova show how to run MCP-powered MSBuild binlog diagnostics inside GitHub Actions so failed PR builds get an automated root-cause comment (with inline suggestions) without anyone downloading logs. They also catalog new Binlog MCP tools and share evaluation data on quality, time, and token usage.
Rahul Bhandari explains what the November 10, 2026 end-of-support date means for .NET 8 (LTS) and .NET 9 (STS), including the practical impact on security fixes, servicing updates, and support, plus what teams should do next to stay on a supported runtime.
Matthew Leibowitz announces SkiaSharp 4.148.0, the first stable release of SkiaSharp v4, and breaks down what changed for .NET developers: an updated Skia engine, new font and image features, API cleanup and lifecycle fixes, and performance improvements, plus links to release notes, samples, and a live event.
Zachary Teutsch explains how WinApp CLI adds Windows package identity to unpackaged .NET desktop apps and streamlines MSIX packaging. The post walks through initializing a project, running and debugging with identity via dotnet tooling, generating manifests/assets, and optionally using a VS Code extension for an F5 run/debug workflow.
Mads Kristensen shows a practical GitHub Actions pipeline for Visual Studio extension authors to build, version-stamp, and publish VSIX packages. It covers an MSBuild-based workflow, publishing to the Visual Studio Marketplace with a secret token, and optionally pushing CI builds to a VSIX Gallery for quick testing.
Wes Steyn shows how Microsoft Agent Framework’s Agent Harness can safely work with user data by adding file access, human approvals for risky tool calls, and durable memory. The post includes both C# and Python examples, plus runnable samples you can use as a starting point for your own agent.

Azure Developer CLI (azd) – May and June 2026

Sandeep Sen and Kristen Womack share the May/June 2026 Azure Developer CLI (azd) roundup, covering new commands like azd tool and azd exec, safer provisioning with azure.yaml dependsOn, improvements to extensions and prompts, and a long list of fixes across deployments, pipelines, and authentication.
jovanpop-msft introduces the Bulk Copy API (preview) for Microsoft Fabric Data Warehouse, explaining when client-side bulk ingestion is a better fit than server-side COPY INTO and showing practical patterns for C#, Java, command-line bcp.exe, and orchestration tools like Azure Data Factory and SSIS.
Lily Ma summarizes what has shipped in the Azure Functions MCP extension since preview, including resource and prompt triggers, MCP Apps for interactive UI, built-in MCP authentication with Microsoft Entra ID, and new .NET fluent configuration APIs for schemas, metadata, and rich content responses.

Visual Studio Code 1.127

The Visual Studio Code Team shares a brief update for VS Code 1.127, noting a change to token pricing normalization to support a legacy flat pricing payload returned by some endpoints.

Azure SDK Release (May 2026)

Justin Bettencourt rounds up the May 2026 Azure SDK releases, including GA for the Azure SDK for Rust and the .NET Azure Batch client library, plus new Azure AI Search knowledge-base retrieval features and preview Azure AI Agent Server hosting libraries across .NET, Python, and JavaScript.

Meet your agent harness and claw

Wes Steyn shows how to build an “agent harness” (a loop around a model with tools, planning, memory, and web search) using Microsoft Agent Framework. The post walks through creating a chat client with Microsoft AI Foundry, wrapping it into a harness agent, and running it in a console UI with plan/execute modes.
Wes Steyn introduces a hands-on series for building a CLI-style “claw” (a coding agent) using Microsoft Agent Framework, explaining the core harness loop—tools, planning, memory, approvals, and observability—and outlining how the sample evolves from a minimal agent to a production-ready service in .NET and Python.

Visual Studio Code 1.126

The Visual Studio Code Team shares the 1.126 (Insiders) release notes, highlighting iterative updates to the chat and Agents experiences, including UI alignment changes, a unified model customization picker, and inline chat renaming.

From package to postinstall payload: Inside the Mastra npm supply chain compromise

Microsoft Defender Security Research Team breaks down an npm supply chain compromise in the mastra/@mastra ecosystem, where a typosquat dependency executed a malicious postinstall payload. The report explains the staged delivery, C2 behavior, cross-platform persistence, and provides Microsoft Defender detections, KQL hunting queries, and concrete mitigation steps.
Jan Krivanek introduces the Microsoft Binlog MCP Server, an MCP server that lets AI assistants (including GitHub Copilot) query MSBuild .binlog files using 15 purpose-built tools for failure diagnosis, property tracing, performance bottleneck analysis, and build-to-build comparisons across Visual Studio, VS Code, and CLI workflows.

Make Visual Studio look the way you want

Mads Kristensen introduces the new Theme colors options page in Visual Studio 2026, which lets you tweak Fluent color tokens directly in the IDE and have changes apply live. He also shows how to share per-theme customizations via JSON overrides and points to updated token documentation.
Leah Tran introduces Visual Studio 18.7’s pull request review experience, which lets developers open PRs, browse diffs, discuss comments, and approve or merge changes from inside the IDE for both GitHub and Azure DevOps repos.
Jeffrey Fritz announces the .NET Day on Agentic Modernization livestream (June 16, 2026), focused on practical ways to modernize existing .NET applications without a full rewrite. The agenda highlights GitHub Copilot-assisted modernization, Aspire-based approaches, migration of WinForms and line-of-business apps, and adding agentic/AI capabilities.

Visual Studio Code 1.125

The Visual Studio Code Team shares what’s new in VS Code 1.125 (Insiders), focusing on Agent Host improvements like the new /chronicle command set for session history, clearer file path display in chat, and updates to Cache Explorer for navigating multi-agent sessions and prompt-signature allocation details.
drew-sk introduces SSMS 22.7 improvements aimed at database DevOps workflows: a graphical schema compare experience, a built-in SQL formatter (including format-on-save for SQL projects), and expanded SQL projects publishing support with SQLCMD variables surfaced in the Publish dialog and supported via SqlPackage.

.NET 11 Preview 5 is now available!

.NET Team announces .NET 11 Preview 5 and highlights what’s new across the runtime, SDK, libraries, C#, ASP.NET Core, .NET MAUI, and Entity Framework Core, with links to detailed release notes and guidance on installing the preview SDK and tooling.

.NET and .NET Framework June 2026 servicing releases updates

Rahul Bhandari and Tara Overfield recap the June 2026 servicing releases for .NET and .NET Framework, including the CVEs addressed in .NET 10.0.9, 9.0.17, and 8.0.28, plus links to release notes, installers, container images, Linux packages, and known issues.

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