Posts

OpenAI’s Codex CLI ships a great editor-agent UX — shell tools, apply_patch, plan tracking, all of it. The catch: as of February 2026, it only speaks the OpenAI Responses API. Chat Completion support was removed (the WireApi enum in codex-rs/model-provider-info/src/lib.rs now has only Responses), which leaves Chat-Completion-only endpoints — Ollama, LM Studio, your favourite Llama runner — locked out. This post walks through how I used .NET 10 file-based programs and the IChatClient abstraction from Microsoft.Extensions.AI to stand up a Responses-compatible server in a single 50-line C# file, with OpenRouter as the backend, so that Codex CLI can run on top of whichever model I feel like that day. ...

Over the weekend I shipped 0.6.0 of DotNetPy, a small C# library that calls CPython’s C API directly to run Python inside a .NET app. This post walks through the three machine learning samples bundled with 0.6.0 — semantic search with sentence-transformers, speech recognition with Whisper, and text-to-image with Stable Diffusion Turbo — and explains how the same release was also validated on PEP 703 free-threaded CPython. Starting Point: You Only Have C#, but the Model Lives on Hugging Face Every few months the same pattern repeats. I need Whisper for subtitles, or a sentence-transformer for search, or occasionally something like Stable Diffusion — but the only tool in hand is C#. The usual workarounds all come with a decisive downside. ...

This article analyzes the design of Microsoft Foundry Hosted Agent, currently in public preview as of March 2026, within the lineage of .NET architecture. This is not a recommendation for production use at this point, but focuses on the design direction that enterprise AI architects should pay attention to. What It Means to Put an Agent in Production When deploying AI agents to production in an enterprise, there are currently two options. ...

C# isn’t becoming as lightweight as a scripting language — scripting languages are becoming envious of how fast it’s getting. Introduction dotnet run file.cs — the so-called file-based app — introduced in .NET 10, lets you run C# code with just a single .cs file, without a .csproj. However, its current execution speed is roughly 1.5 seconds on Windows and 0.8 seconds on WSL2 for the first run. Compared to Python’s python script.py at around 50ms, it’s hard to call this “scripting” with a straight face. ...

2026-02-08 — LibraStudio Dev Log #1 Background Why Another .NET IDE? The IDE options in the .NET ecosystem are actually quite limited. Visual Studio is powerful but Windows-only, and even the Community Edition has restrictions on commercial use. The VS Code + C# Dev Kit combo is great, but the fact that C# Dev Kit is proprietary doesn’t change. Ultimately, vendor lock-in occurs at critical points, and the entire tool chain and workflow built on top becomes dependent on a specific vendor’s decisions. ...

Open Source Contribution in the AI Era: Lessons from the HwpLibSharp Porting Project I’ve been a Microsoft MVP for 17 years now. One of the most frequently asked questions I’ve received in the .NET community is “How do I work with HWP files in C#?” The official library from Hancom was built on Windows and COM, leaving virtually no solution for cross-platform .NET environments. Then I discovered hwplib by @neolord0—a pure Java open source library that parses the HWP file format. The thought immediately struck me: “Porting this to .NET would be a real contribution to the community.” But it wasn’t going to be easy. The codebase was massive, and it was still being actively updated. ...

When following news from the AI coding tools industry these days, you’ll notice that every time a new tool emerges, messages like “this is the future” and “you’ll fall behind if you don’t use it” are emphasized to an almost excessive degree. Background agents, parallel AI sessions, autonomous coding—new concepts appear every week, making you feel like you’re falling behind the times if you don’t adopt them. But is it really healthy to take these messages at face value? I don’t think so. ...

It Started with Simple Curiosity “I wish I could handle HWP files directly in .NET…” I’m probably not the only .NET developer who has had this thought. HWP files are still widely used in Korea, especially in government agencies, but the .NET ecosystem lacked a proper open-source library to handle them. Previously, the only way to work with HWP files in .NET was to use the HWP ActiveX control’s COM type library that comes with Hangul (the word processor), limited to Windows. Unfortunately, even this support has been discontinued, leaving us with no options. ...

Introduction If you’ve ever used internet banking in Korea, you’ll be familiar with the numerous security program installation requirements. While ActiveX has disappeared, countless security plugins that replaced it—AhnLab Safe Transaction, TouchEn nxKey, Veraport, and more—still demand installation on our PCs. The TableCloth project is an open-source tool that allows you to run these security programs in an isolated Windows Sandbox environment. The TableCloth Catalog serves as a database that organizes which security programs are required for each financial website. ...

What is the TableCloth Project? TableCloth is an open-source project that helps users safely use security plugins required for Korean internet banking in a Windows Sandbox environment. It runs security programs required by various financial institution websites in an isolated environment, ensuring the safety of the host system. What is the Catalog Repository? The TableClothCatalog repository stores the list of security programs required for each financial institution site referenced by the TableCloth project. Security plugin information required by websites of banks, securities firms, and insurance companies is systematically organized here. The catalog builder tool processes this information into a format usable by the TableCloth app. ...