Niels Swimburger.NET 🍔

NCrontab Expression Tester Evaluator Use the NCrontab Expression Tester tool to test out your NCrontab/CRON expression and see the DateTimes of your occurrences.

I gave my Blazor based ncrontab testing tool a facelift
ncrontab.swimburger.net
#dotnet #csharp #blazor #aspnet

I updated my Blazor based de/compression tool with support for gzip, brotli, deflate, zlib, and zstd.
#dotnet #csharp #blazor
gzip.swimburger.net

Good pun!

cursed

Join the Fern team We are a tight-knit team passionate about developer tools. We’re also musicians, DJs, photographers, wine enthusiasts, runners, dog lovers, and more.

We got to touch some grass (and snow) over the holidays, but now it's time to lock in. With Postman's backing, we're going to take developer tooling to the next level.

We're hiring: buildwithfern.com/careers
Read more: buildwithfern.com/post/postman-acquires-fern

Danny, Deep, and the team have built something special here, and it starts with how they hire and the culture they've created. I've been very fortunate to work alongside some of the most talented engineers I've ever met, in a team that genuinely enjoys building together.

I own multiple SDK generators, touched nearly every corner of the codebase, and helped customers like Square go live with multiple SDKs.

Jack (Labradoodle dog) laying his head on my laptop.

𝗙𝗲𝗿𝗻 𝗵𝗮𝘀 𝗷𝗼𝗶𝗻𝗲𝗱 𝗣𝗼𝘀𝘁𝗺𝗮𝗻!

A year and 4 months ago, Jack (my labradoodle) and I packed up and moved to NYC to join Fern. He's the best office perk—still waiting on his equity though.

"I'm descended from wolves"

How we enforce web API standards and guidelines at Workleap We automate API specs as first class citizens, keeping them versioned, validated, and checked for breaking changes in ASP.NET Core projects.

Extract OpenAPI specs from #dotnet web apps automatically. Fail CI checks if the spec isn't synced with #csharp code, validate it against Spectral rules, and catch breaking changes. All handled at build time by a single NuGet package made at Workleap.

medium.com/p/8a535d813244

How to generate a TypeScript SDK for your API spec | Fern Learn how to deliver a TypeScript SDK that’s lightweight, fully type-safe, and works across all JavaScript runtimes with Fern.

Having experienced these challenges firsthand at AssemblyAI, I'm now working full-time on a TypeScript generator at Fern. I've written about today's development challenges and what it takes to deliver exceptional TypeScript SDKs in 2025.

buildwithfern.com/post/generat...

Now I'm building libraries that need to work seamlessly across browsers, multiple Node.js versions, Bun, Deno, edge runtimes like Cloudflare Workers and Vercel Edge Runtime, and yes, React Native too. The complexity has exploded, but our tooling hasn't kept pace.

I've been working with JavaScript since the days when browser compatibility was our biggest headache. Supporting IE6 and the original Edge alongside Chrome and Firefox felt challenging at the time. But that was nothing compared to today's reality.

Watch @damianedwards.com blow your mind with the demo!

youtu.be/98MizuB7i-w

#dotnet #csharp

Announcing TypeScript Native Previews - TypeScript Previews of the native TypeScript port are now available on npm and for VS Code through the Visual Studio Marketplace!

devblogs.microsoft.com/typescript/a...

Beautiful

YouTube video by Veritasium How One Company Secretly Poisoned The Planet

youtu.be/SC2eSujzrUY?...

I went on holiday for two weeks and I feel like VSCode + Copilot improved a lot in just that little time.
It feels a lot smoother and better predictions.

New async Zip APIs in .NET 10 preview 4! Fantastic that this gap is bridged :)
github.com/dotnet/core/...

Proxyman · Debug, intercept & mock HTTP with Proxyman Proxyman is a native, high-performance macOS app, which enables developers to capture, inspect, and manipulate HTTP/HTTPS requests/responses with ease. Support iOS and Android Simulator and Physical D...

My favorite dev tool this year has been Proxyman. It's a well crafted super useful tool for anyone working with HTTP APIs.
Money very well spent!

proxyman.com

I was able to achieve a pretty good UX cobbling together some System.Text.Json extensibility points. Feedback appreciated!

Join the Fern team We are a small, tight-knit team building dev tools for the largest API-first companies in the world. We’re also musicians, DJs, photographers, wine enthusiasts, runners, and more.

Check out our roles: buildwithfern.com/careers

Jack (labradoodle) with role Barkitect

Want to work on really cool developer facing products?
We have a couple of open roles in Brooklyn and you get a proximity bonus for living nearby!

The best perk is the support from Chief Barkitect Jack.

BRING BACK DYNAMIC

How to create a symmetrical JSON class for reading and writing that is intuitive with [JsonExtensionData]? · Issue #114106 · dotnet/runtime We're experimenting with how we can provide the most intuitive, developer friendly experience for reading and writing additional properties for OpenAPI and are struggling to use [JsonExtensionData]...

Anyone using [JsonExtensionData] in .NET that has suggestions here?
github.com/dotnet/runti...

We’re excited to launch Square's .NET SDK today, git.new/1WyYbPA! We sweat over the details so Square doesn't have to — here’s what makes this release stand out: (1/3)

GitHub - square/square-dotnet-sdk: .NET client library for the Square API .NET client library for the Square API. Contribute to square/square-dotnet-sdk development by creating an account on GitHub.

Check it out: github.com/square/square-dotnet-sdk

⚡ P.S. Also optimized webhook signature verification with Span<char> & Span<byte> to reduce allocations.

GitHub - square/square-dotnet-sdk: .NET client library for the Square API .NET client library for the Square API. Contribute to square/square-dotnet-sdk development by creating an account on GitHub.

Just shipped Square's .NET SDK:
🔄 Modern C# & .NET with .NET Framework 4.6.2 compatibility
📦 System.Text.Json (no Json.NET) with minimal dependencies
✨ IAsyncEnumerable pagination, discriminated unions & forward-compatible enums
🧪 300+ tests including 88 migrated integration tests

feat: Optimize request validator + make thread safe (backwards compatible) by Swimburger · Pull Request #660 · twilio/twilio-csharp All third-party contributors acknowledge that any contributions they provide will be made under the same open-source license that the open-source project is provided under. ASP.NET Core is pushing ...

You get the brightest people in the .NET community to review your PR, but clearly Twilio doesn't care about C# or .NET.
github.com/twilio/twili...

I'm done with Twilio 🤡