Dive into the biggest news from Microsoft Build and learn how to start building with it today 👇

Introducing run-assert-eval. With a single prompt in @code, the skill identifies risks specific to your agent, measures how often they occur, generates runtime policy based on those findings, and reruns the same eval to see whether the policy worked. commandline.microsoft.com/ru…
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The skill ships in the ASSERT repo with seven worked domains and 14 risk suites: github.com/responsibleai/ASS…
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Claude Opus 5.5, Anthropic’s newest Opus model, is now available in GitHub Copilot and Microsoft Foundry. In early testing, Opus 5.5 resolved tasks comparably to Claude Opus 5 while using significantly fewer steps and tokens.
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Microsoft Developer retweeted
Build agentic apps with the GitHub Copilot SDK, without implementing the agent loop yourself. Join this beginner-friendly livestream to learn how to use sessions, tools, MCP servers, streaming events, and more to embed Copilot’s agent runtime in your apps. Plus, check out specific sessions for .NET and Java development. No prior SDK experience required. Register for English, Chinese, Portuguese, Spanish, Japanese, or Korean 👇 gh.io/letslearn
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Microsoft Developer retweeted
Yes or YES? Get your #GitHubUniverse pass 👇 githubuniverse.com/?utm_sour…
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never starred two repos so fast
Developers are buzzing. We thought these were pretty fly... 🪰 github.com/nftechie/doomfly github.com/mattyhempstead/fl…
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Microsoft Developer retweeted
GitHub is proud to sponsor this year’s Open Source Accessibility Summit! Open source is stronger when everyone can participate and contribute. Join us to explore the Open Source Accessibility Framework, connect with the community, and help turn accessibility goals into lasting progress. Everyone is welcome. 💙 2026.allthingsopen.org/open-… #OpenSourceAccessibility #OpenSource #Accessibility #A11y
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Microsoft Developer retweeted
Portable Computer is now available on Windows PCs with @NVIDIA RTX GPUs. Run the harness, agents, and models locally on your PC. Work with local files and connected apps without sending tasks to the cloud. Use frontier cloud models when needed.
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GitHub CLI now lets you attach local images and videos with --attach, so you can add media directly to issues, pull requests, and comments without leaving the command line. See it in action from @madebygps
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Clear your calendars tomorrow for four hours of GitHub Copilot. We’ll get into agents, models, the CLI, VS Code, live demos, new stuff, and plenty of code along the way. Tune in and hang out with us. nitter.net/i/broadcasts/1vJpPNqoV…
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We built ThinkingBox to measure whether agents actually finish the job. ThinkingBox runs agents in isolated, stateful tool environments, lets simulated users answer follow-up questions, and inspects the side effects left behind. commandline.microsoft.com/th…
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Try ThinkingBox 👇   github.com/microsoft/thinkin… contains the runtime.  github.com/microsoft/thinkin… contains the benchmark tasks, synthetic records, and MCP servers.
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Welcome to MCP Live! Join us for a half-day of MCP, from how it’s being adopted across the developer ecosystem to hands-on sessions on MCP at @github, building MCP servers with @code, and more. piped.video/watch?v=uydwDk91…
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Starting soon 👇
Join us September 9 for MCP Live! Dive into sessions on MCP at @github, building MCP servers with @code, using Toolboxes for a unified MCP layer in Microsoft Foundry, and more.
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Microsoft Developer retweeted
The Story of VS Code | Official Trailer 🎥 Watch The Story of VS Code on Friday, September 4th at 8am PT. 👉🏽 subscribe to the VS Code YouTube channel to be notified as soon as the documentary drops: aka.ms/the-story-of-vs-code #vscode #storyofvscode
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Microsoft Developer retweeted
Claude Fable 5.1, the latest in @AnthropicAI's Mythos model class, is now generally available in GitHub Copilot. In our testing it showed strong performance on ➡️ long-running coding tasks ➡️ deep codebase research ➡️ complex agentic workflows Try it out in the GitHub Copilot app, CLI or @code. github.blog/changelog/2026-0…
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This is the story of how @code got here, told by the people who built it and the developers who helped shape it.
Visual Studio Code
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Who spent all the tokens? đź‘€ TokenOps gives multi-agent workflows one shared, run-scoped budget, with policies that can step in before the next model or tool call executes. The result is real-time control over spend and agent behavior while the run is still happening.
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