Microsoft
Developer Blogs

Get the latest information, insights, and news from Microsoft.

Highlights

How to test agent skills without hitting real APIs

Your agent skill calls an API. The moment you start evaluating it, every run either costs money or mutates production data. Learn how to mock APIs transparently so you can run evals without changing your skill or hitting real endpoints.
Read moreClick to read more about this post

Latest posts

Jul 21, 2026
Post comments count0
Post likes count0

How to test agent experience changes without shipping them

Waldek,
Garry
Most changes you think will improve AI agent behavior won't. We tested a dozen hypotheses on a real project upgrade scenario and the majority failed. Learn how to emulate documentation, API, and MCP server changes locally so you can validate what works before shipping anything to production.
Microsoft for Developers
Jul 20, 2026
Post comments count0
Post likes count1

C++ Dependencies Without the Headache: vcpkg + Copilot CLI

Augustin Popa
At Pure Virtual C++ 2026, we build a C++ console app from an empty folder using CMake, MSVC, and GitHub Copilot CLI. This walkthrough shows a practical prompt sequence for dependency selection, reproducible builds, and controlled updates.
C++ Team Blog
Jul 20, 2026
Post comments count0
Post likes count0

Pure Virtual C++ 2026 Is Tomorrow and On-Demand Sessions Are Now Available

Marian Luparu
The on-demand sessions for Pure Virtual C++ 2026 are available now on YouTube. Watch seven talks on SPGO, vcpkg + Copilot CLI, CMake Tools, PackageReference, MSVC upgrades, and C++23/26 status — then join us live tomorrow.
C++ Team Blog
Jul 20, 2026
Post comments count0
Post likes count0

Announcing a New Visual Manifest Editor in the WinApp VS Code Extension

Chiara Mooney
The WinApp VS Code extension exists to make Windows app development feel at home in VS Code. It brings the Windows App Development CLI right into the editor, so you can initialize, run, debug, package, and sign Windows apps built with .NET, WPF, WinUI, C++, Electron, Rust, Tauri, or...
#ifdef Windows
Jul 20, 2026
Post comments count1
Post likes count2

T-SQL Hygiene: Introducing the Covering Index

Jerry Nixon
Often in applications, we write database queries. And often, the same query is executed again and again. To make queries against large tables faster, we can add an index. This is a general improvement for anyone accessing the table. However, there is a specially designed index called a...
Azure SQL Dev Corner
Jul 20, 2026
Post comments count0
Post likes count1

AI agents, meet the Azure Cosmos DB vNext emulator

Abhishek Gupta
If you use the Azure Cosmos DB vNext emulator, you probably know the local development loop: start the emulator, connect to it, create some resources, load test data, run queries, and inspect the results. Each step is straightforward, but together they add setup work before you can test...
Azure Cosmos DB Blog
Jul 20, 2026
Post comments count2
Post likes count2

Making an agile version of a Windows Runtime delegate in C++/WinRT, part 1

Raymond Chen
The easy case is easy.
The Old New Thing
Jul 17, 2026
Post comments count0
Post likes count1

Faster C++ iterative builds with GitHub Copilot

David Li
Slow builds are a consistent theme of feedback from C++ developers. We built GitHub Copilot build performance for Windows so you can leverage Copilot to optimize your project’s build times. This workflow will find optimizations that bring your build times down. At first, we only...
C++ Team Blog
Jul 17, 2026
Post comments count6
Post likes count3

Why has the display control panel pointer truncation bug gone unfixed for so long?

Raymond Chen
It's fixed, but the fix isn't getting there.
The Old New Thing
Jul 17, 2026
Post comments count0
Post likes count0

How to test agent skills without hitting real APIs

Waldek Mastykarz
Your agent skill calls an API. The moment you start evaluating it, every run either costs money or mutates production data. Learn how to mock APIs transparently so you can run evals without changing your skill or hitting real endpoints.
Microsoft for Developers
Jul 17, 2026
Post likes count0

Teaching a Vision Model to See Like a Human Annotator—and Catching It When It Lies

Deeptanil,
Kartheek
A multimodal LLM enrichment pipeline that extracts structured metadata from visual assets, constrains output to predefined values to minimize hallucinations, and uses a ground truth evaluation template to measure quality—all as a plug-and-play module.
ISE Developer Blog
Jul 16, 2026
Post comments count0
Post likes count0

Pure Virtual C++ 2026 [Meet the Speakers, Part 3]: Modernizing C++

Marian Luparu
Meet the speakers behind Pure Virtual C++ 2026. In the final part, Victor Ciura maps the real challenges and promising directions for C++/Rust interop.
C++ Team Blog
Jul 16, 2026
Post comments count0
Post likes count0

Build Once, Run Everywhere: Unified Manifest for Office Add-Ins now Generally Available

Office Extensibility team
Unified manifest support for Word, Excel, PowerPoint, and Outlook makes it possible for developers to build a single app that works across Microsoft 365 apps, creating a more consistent experience for users and a simpler deployment model for IT admins.
Microsoft 365 Developer Blog
Jul 16, 2026
Post comments count1
Post likes count2

T-SQL Hygiene: What's the Big Deal with SET NOCOUNT ON?

Jerry Nixon
Learn why SET NOCOUNT ON improves stored procedure efficiency, reduces unnecessary messages, and matters to .NET developers.
Azure SQL Dev Corner
Jul 16, 2026
Post comments count0
Post likes count2

Announcing .NET Modernization for Beginners

Pablo Lopes
A free, open-source, hands-on course that walks you through modernizing a real legacy ASP.NET application all the way to .NET 10 using the GitHub Copilot modernization agent, step by step.
.NET Blog
Jul 16, 2026
Post comments count0
Post likes count0

How to build long-running MCP tools on Azure Functions

Lily Ma
Learn how to build long-running MCP tools on Azure Functions using Durable Functions. This post explains why synchronous tool calls break down for long-running work, introduces the MCP Tasks extension, and walks through a sample pattern that works with existing request/response clients today.
Azure SDK Blog
Jul 16, 2026
Post comments count1
Post likes count1

Visual Studio Administrator? Join our Private Marketplace Preview!

Ruben Rios
Organizations are increasingly looking for greater control over extensions within development environments. Driven by security, compliance, and internal governance requirements, teams want more visibility into how developers discover and acquire extensions. To address these needs,...
Visual Studio Blog
Jul 16, 2026
Post comments count3
Post likes count3

Speculating on how the buggy control panel extension truncated a value that it had right in front of it

Raymond Chen
Inferring the code's history.
The Old New Thing