Show HN: I built a web framework in C

(github.com)

141 points | by ashtonjamesd 4 hours ago

32 comments

  • faxmeyourcode 2 hours ago
    This is some of the cleanest, modern looking, beautiful C code I've seen in a while. I know it's not the kernel, and there's probably good reasons for lots of #ifdef conditionals, random underscored types, etc in bigger projects, but this is actually a great learning piece to teach folks the beauty of C.

    I've also never seen tests written this way in C. Great work.

    C was the first programming language I learned when I was still in middle/high school, raising the family PC out of the grave by installing free software - which I learned was mostly built in C. I never had many options for coursework in compsci until I was in college, where we did data structures and algorithms in C++, so I had a leg up as I'd already understood pointers. :-)

    Happy to see C appreciated for what it is, a very clean and nice/simple language if you stay away from some of the nuts and bolts. Of course, the accessibility of the underlying nuts and bolts is one of the reasons for using C, so there's a balance.

    • citizenpaul 2 hours ago
      > I'd already understood pointers.

      Ok I hear this all the time. Are pointers really that hard for so many people to understand? I'm not trying to brag it took me I think like 15 minutes to grok them from learning about them the first time. I'm sure it took me longer to be proficient but I don't get this legendary difficulty aura that seems to surround their existance.

      Also yes nice project.

      Job app complete projected archived and abandoned in 3...2..1... :). I hope not.

      • wkjagt 18 minutes ago
        I understood them on a superficial level when first learning about them, but it only really clicked after having done assembly.
      • noufalibrahim 1 hour ago
        It's a rabbithole. Pointer to array of structures that have pointer fields. Array of pointers to structures etc. You pass them around and trip over the passing semantics, uninitialised pointers etc etc.
        • citizenpaul 43 minutes ago
          Hmm. Perhaps I've just never encountered a hairy enough situation with them? That's what the eternal thought tracker notepad on my desk is for though. Maybe people are trying to do it all in their head? Pen and paper are too old school for the cool new 1000x devs?

          I still feel like this argument could be transferred to nearly any concept in CS though. Abstract enough anywhere and you will always start exceeding the brains working memory.

      • assimpleaspossi 1 hour ago
        Same here about pointers. Perhaps it's cause I started life as an electronic engineer and understood memory addressing from the chip level but I, too, don't understand the struggle others seem to have.
        • citizenpaul 37 minutes ago
          I started in networking so there were a lot of memory/bit-logic/binary concepts piled on early maybe that is the case.
      • copperx 1 hour ago
        The concept is straightforward. The syntax isn't. That's why cdecl.org exists.
        • citizenpaul 41 minutes ago
          C gibberish to English gave me a chuckle thanks.
    • ashtonjamesd 2 hours ago
      Wow! That really means a lot because I always make a lot of effort to make sure my code is just that :)

      Appreciate you saying that!

      • jacquesm 2 hours ago
        You've done a couple of things right: very few dependencies, simple, easy to understand code. C gets hairy when you try to be clever.

        I'm busy writing some of the most optimized-but-still-portable code that I've ever written and it is very interesting to see how even a slight difference in how you express something can cause a massive difference in execution speed (especially, obviously, in inner loops). Your code is clearly written from what your comfort zone with C is and I'm really impressed by the restraint on display. At the same time, some of the code feels a bit repetitive and would benefit from more universal mechanisms. But that would require more effort and I'm not even sure if that is productive. One part where I see this is in the argument parsing code as well as in the way you handle strings, it is all coded very explicitly, which substantially increases the chance of making a mistake.

        Another limitation is that using AI to help you write the code means you don't actually understand what it does, and this in turn may expose you to side effects that you are not able to eliminate because you did not consider them while writing, it is as if someone else gave you that code and asked you to trust them they did not make any mistakes.

  • freetonik 3 hours ago
    I hope you don't feel discouraged by some comments questioning the meaningfulness of this. It's a cool project, and you obviously put some thought into it. Congrats!
    • freetonik 3 hours ago
      In addition, OP clearly describes themselves as a "Fanatical C Developer", so that's enough justification in my book! :)
      • Teknomadix 2 hours ago
        Doing what you love is fully justified in 2025.
    • ashtonjamesd 2 hours ago
      No of course not, I understand where they are coming from in all honesty. Thank you that means a lot!
  • lubesGordi 3 hours ago
    Well I don't know about others here, but I think its cool. If you can make the setup super readable and get the performance of C then why not? Especially now when you can get claude to write a bunch of the framework for you. Add in whatever you need whenever you need it and you automatically have a platform independent web framework that's no bigger than what you need and likely decently performant.
    • maybewhenthesun 3 hours ago
      Maintainer nightmare checklist:

      - Web framework : inherently hard to maintain due to communication over evolving standards. Check.

      - AI written code where nobody knows howwhatwhenwhy!? Check.

      - Written in C. Check.

      bwahahahaha!

      edit: semi-joking. As I actually like the simplicity of pure C. But the combination of AI written,network-facing and C makes me shudder.

      • ashtonjamesd 2 hours ago
        Haha, I have used AI in some parts of it - mainly the JSON part because I could not wrap my head around it for the life of me. But I am proud that 90% is self written!
        • jvanderbot 2 hours ago
          That is excellent. Well done.
      • jvanderbot 2 hours ago
        I think the old HN ethos that I loved, on full display here, won't survive intact in the AI era. It'll have to change from "It is cool to try making <neat tool> in <non obvious language>". Such a project is now a prompt away, and there's light-years of distance between a carefully hand crafted version and something that is posted aspirationally by an AI.

        Every agent I know of or use will always say they built "Production ready, secure, fast package for X" if you ask them to build that, but they rarely actually will. It takes enormous time and effort to actually do that, and any first iteration of "production ready" is definitely aspirational until it actually hits the real world and survives. I'm speaking from experience, fwiw.

  • codegeek 2 hours ago
    People, stop trying to be so serious and nitpick this project. This is a great example of an actual HN worthy share. Someone built a cool project and explored the possibilities with C. This is not something we need to analyze with "oh can it replace PHP" etc.

    Good job OP. Now if you can add HTML templating, this may become a complete framework :)

    • ashtonjamesd 2 hours ago
      Thank you, I really appreciate you saying that!

      Yes it's on the backlog and will be fun to implement :)

  • sroerick 2 hours ago
    Hi, I think this is great. I've really enjoyed working with Jetzig, which is sort of similar.

    I also love the BSD C CGI Postgres stack. I'm just a CRUDmonkey with mostly python skills, so getting to explore low language and memory concepts is a lot of fun for me.

    People will whine and moan about how this is not practical, but as embedded devices become more ubiquitous I think a clear value add may actually emerge.

    I've been playing with the pico calc, and if I was building something as a "mobile app" for that I would much rather reach for C for my framework code.

    Cheers, great work

  • levkk 3 hours ago
    That's awesome. With macros, you can go far and most modern web frameworks use whatever complex tools their language allows (like metaprogramming in Rails).

    Mad props for building this. It's hard and it's fun!

    As to other comments in the thread about the "why": why not. For the love of the craft.

    • ashtonjamesd 2 hours ago
      Thank you so much! I appreciate it :) And yes, totally agree.
  • hgs3 2 hours ago
    The code is very readable and well organized. My only major critique is that there's very little error checking, e.g. there are many calls to snprintf and malloc without checking the result. There is also an unused loop here [1].

    As an aside, I don't see any support for parallelization. That's fine for an initial implementation, but web servers do benefit from threading off requests. If you go that route (pun intended) you might consider using something like libuv [2].

    [1] https://github.com/ashtonjamesd/lavandula/blob/51d86a284dc7d...

    [2] https://github.com/libuv/libuv

    • ashtonjamesd 2 hours ago
      Thank you for the feedback, it is appreciated!

      I did intend to implement parallelization as a later feature so it's good to bring it up.

  • fallingmeat 3 hours ago
    wow that’s a lot of HATE for a really well organized project with some great ideas. Killer job Ashton, you just built some skills they can’t take away from you.
  • jacquesm 2 hours ago
    If you're going to use local allocation of short lived buffers then don't use malloc but use alloca. That's much cleaner.

    http.c around line 398, that looks wrong.

    • gpm 59 minutes ago
      I've been told that modern compilers really don't like alloca, is that wrong?
      • jacquesm 54 minutes ago
        I don't know who told you. But it's a lot slower than malloc, and requires you to do a bunch of bookkeeping, which is easy to mess up if you have multiple exits from your function.
  • orochimaaru 1 hour ago
    This is very cool. I may take the same concepts you have and do this in rust and zig for fun and learning.

    Yeah, I know those languages have a the frameworks but nothing really beats understanding something like doing it ground up on your own.

  • p0w3n3d 3 hours ago
    Great work! Thank you! That's what I've been looking for for a long time.

    Still probably I'm going to continue learning golang in most situations, because that's where the money is (i.e. job offers), but I will create a hobby project based on your framework.

    --- EDIT ---

    > 5 hours ago

    Ohh it's fresh. I almost smell the freshly baked buns with my mind

    • ashtonjamesd 3 hours ago
      That's amazing to hear and motivates me to solidify the framework further. I appreciate you showing interest! :)

      I'd love to hear about your project when you get round to it.

  • dboon 2 hours ago
    C is really, really ripe for tooling and modern libraries. There are a lot of great ones already that don’t resemble what I’ll call university C in the slightest (i.e. the C most of us remember writing; awful, bug filled, segfaulting)

    I’ve been building out my C standard library replacement in earnest for a little while. If you like this framework, check it out.

    https://github.com/tspader/sp

  • sim7c00 1 hour ago
    really nicely written. inrespect this is maybe known / unneeded comment, but why bother with basic auth at all, especially when there is no TLS?

    i understand other auth schemes are more complicated, and maybe theres no desire to pull in big libraries. just that if theres no TLS or proper auth, you can also just skip basic auth. its only use would be to trick someone who's not familiar (unlikely with such a repo but not impossible) into a false sense of security.

    ofc, not really an issue with the code, and its an excellent base to look into how this stuff works and if you want since its pretty clean and easy to ready, expand upon it. well done! love ppl churning out good ol C projects. respect!

    • severino 1 hour ago
      > why bother with basic auth at all, especially when there is no TLS?

      Maybe to have some "basic" auth for an embedded device web interface or something like that? I suppose it's better than nothing. I've devices which prompt for username and password with no TLS either.

  • elevation 2 hours ago
    I have considered porting a couple production apps from python to C; at this stage in their lifecycle they would benefit more from C's execution speed than from python's development speed.

    Your work is a nice reference, it is neat to see someone else working in this space!

  • OutputRiff 2 hours ago
    The repo looks fantastic! I'd love to see a demo and didn't seen one readily available in the readme.

    I had such a bad experience with GWT back in the Java days of my life that I've steered clear of any "server" language for web frameworks since. I'd love for that to change though. I definitely will be trying this out.

  • gwbas1c 3 hours ago
    I don't understand the example. Does it even compile?

    It's been a long time since I've used C, so maybe it's using some syntax that I'm unaware of?

    IE: What defines "home" that is referenced as an argument to the "appRoute" function, and then passed to the "get" function to set up the "/home" route? Is "home" defined in lavandula.h, or is this really pseudocode?

    • ashtonjamesd 3 hours ago
      Hi, sorry maybe I should've added a comment for that.

      The 'appRoute' is a macro that expands to a function signature.

      The macro is: '#define appRoute(name) HttpResponse name(AppContext ctx)' and the parameter I passed as 'home' is expanded into the function name. The reason is because all controller function signatures are the same, so just writing 'appRoute' allows the developer to save time writing endpoints!

      It is a tradeoff between readability and development speed. And one of the ideas behind the framework is succint and minimal code.

      • gwbas1c 2 hours ago
        So it creates a function called "home", and that is what you pass to get?

        Makes sense, thanks!

    • hofrogs 3 hours ago
      "appRoute(home)" is a macro that expands to a function called "home":

          #define appRoute(name) HttpResponse name(AppContext ctx)
    • rnhmjoj 3 hours ago
      If I can guess, I would say `appRoute` is a macro that defines a struct called `home` with that handler being assigned to some field as a function pointer.
    • diath 3 hours ago
      It's a macro:

          #define appRoute(name) HttpResponse name(AppContext ctx)
  • elevation 2 hours ago
    Nice work! I like the little test framework you built. Have you considered making runTest a macro so that you can print the name of the test along with the test result?
    • ashtonjamesd 2 hours ago
      That's a very good idea actually and I had wanted to do that but it didn't click that you could do that with a macro!

      Thank you, I'll will implement that :)

      • elevation 1 hour ago
        For the ultimate in readable test reports, you can prettify the test name by:

        * dropping the prefix "test_" * substituting the "_" characters in the function for whitespace * uppercasing the first letter of each word.

        So `test_tokenize_simple_model` becomes "Tokenize Simple Model".

  • coreyp_1 2 hours ago
    I'm wanting to do the same thing. I've also already written a language (in C) to generate HTML (a template language), so these two go hand-in-hand!
  • dariosalvi78 1 hour ago
    How compatible is this with embedded devices? How much does this depend on OS APIs?
  • jcmontx 2 hours ago
    I often forget how similar to Golang C looks and feels
  • capestart 2 hours ago
    This looks cool
  • defraudbah 2 hours ago
    github is giving me 503, the project is too good for mS

    Thanks for sharing, this looks amazing

  • JKCalhoun 3 hours ago
    I'm stupid — is this to create web apps that run on the server? More or less replacing PHP or whatever?
    • ashtonjamesd 3 hours ago
      Right now, it's just a framework for building backends. So yes, server-side applications. However, I have thought about implementing a templating engine for serving HTML files.
      • Hackbraten 3 hours ago
        This can be super useful for IoT or embedded devices with web interfaces but restricted resources.
      • sixtyj 3 hours ago
        Edit: I am considering to delete the following paragraph as it seems that my hands were quicker than my brain :)

        I'm sorry, but it's like scratching your left ear with your right hand. But for fun, yeah, there are worse things people do. Good luck and have fun. Now here's where most of us will probably be sarcastic, but it's certainly a good way to explore whatever others consider bullshit.

        Edit: Pls read the following comment. I would hire him/her because I consider this as a waste of OP skills and he/she would be useful in many more projects.

        TLDR; it was not a hate. I am sorry if it sounds so.

        • ashtonjamesd 3 hours ago
          True. Also, I love the C language and I don't get joy out of writing in many other languages. Additionally, I've wanted to make something like this just to learn more about how web servers work. I appreciate your thoughts.
          • sim7c00 1 hour ago
            love this sentiment. i cant really write in other languages. i try but always C ends up the choice :'). slow going but happy going
          • sixtyj 3 hours ago
            It is not about threat. It is about that life is too short to do things that are almost nonsense. Ofc everyone of us consider “nonsense” in different way.

            I wish OP good luck. It was not sarcastic, I really do, and would like to hire him/her for the skills. But for mankind, this project is almost useless… I apologize if this sounds harsh.

            • ashtonjamesd 3 hours ago
              That's fair. And I do agree. The use cases for something like this are very thin compared to what tools you can use out there instead, Django, Rails, Express, etc. All of which offer a much safer development experience. However, I still believe it will have a use case for some.
              • sixtyj 2 hours ago
                You are right. But I really think if you know C lang (all of Python or PHP people could be jealous :) - you can easily focus on something a little bit important/useful that will have impact on humanity.

                You have a great potential if you can “see code” and have logical thinking deep inside. Not too many people have it.

                Elon Musk said once that all those innovations are redeemed by the tremendous efforts of all the engineers. So I appreciate everyone who can do something.

            • seanssel 2 hours ago
              Oh please, get off the weird high horse. I find this comment to be “nonsense”. What projects are you working on now, for mankind?
              • sixtyj 2 hours ago
                Why are we alive? To be useful. Not happy all the kind. Everyone wants to be useful.

                I am not doing anything special but I do inform our community (“mankind”) for 25 years… And I feel useful because I am good at it.

                “Mankind” can be a group of other people.

                Edit: What people value the most? Compliments. So if you are useful and receive compliments, you will eventually be happy. But ofc you can be happy without being useful, for sure.

                • chrsig 2 hours ago
                  to be useful to whom, exactly?
                  • sixtyj 2 hours ago
                    To other people, of course.
                    • jacquesm 1 hour ago
                      OP has done more to be useful to other people than you did in this particular thread. Ok, so what if it has been done many times before, this is his, it may not be perfect and it may not be immediately useful to you. But it increased his knowledge and he shipped, which is more than I can say for 95% of my own projects, so that's impressive by itself. He also opened himself up to criticism and takes it all in stride, which is another fairly scary but powerful thing to do.

                      Fun fact: I've built something very much like this that powered a number of programs that I sold over the years and it was written when I wasn't nearly as good of a programmer as I am now (take off 30 years of additional experience). If I look at OP's code there are a whole raft of nitpicks but there isn't anything immediately and obviously wrong with it and just speaking for myself, that is surprising because most people's C code is - and I'm being generous here - absolutely terrible. This has potential, but I'd have to really dig in to see how solid it is and I don't have time for that right now, but I've seen far worse code than this.

        • password54321 3 hours ago
          Why do web developers feel threatened that someone just built a web framework for fun?
          • jermaustin1 3 hours ago
            As a web developer who's first paid web site was in 1998 when I was 10-years-old, my favorite thing to do in my spare time is build web frameworks that I will never use.

            - I've done CSS frameworks that replicate most of bootstrap that I use.

            - I've made client-side reactive web-components (kind of) that almost replaced the parts of react that I like.

            - I've built bespoke HTTP servers countless times since the VB6 days.

            - And I've written my own MVC engines probably a half dozen times, just to learn a new language or library.

            All of that to say, it isn't web devs who are threatened, it is developers who don't want to learn the underlying technologies that power the libraries and frameworks they use.

            I actually see no fault in being that way. I've know tons of decent-to-good developers that have no desire to understand HTTP or Vanilla JavaScript, and they still do great work tying systems together. It's all about the kind of learner you are. Do you want depth, breadth, or a mixture of both (but always lacking in both - aka me).

            • sixtyj 2 hours ago
              That is what I wanted to say too… but I did it wrong way in previous comment.. oops
              • jermaustin1 2 hours ago
                We all trip up on our words sometimes. To err is human.
        • jermaustin1 2 hours ago
          An old boss of mine was an early developer for match.com, their entire web app was a monolithic C application, and, if I'm not mistaken, an ISCSI shared file-system based "database".
          • sixtyj 2 hours ago
            All big projects eventually have a specific background. I totally agree. Sometimes it works. Other times it doesn't work in long term and the cursed technology debt catches up with the company.
  • globalnode 2 hours ago
    I like this, thanks for sharing. I recently did some work with a python web server using the basehttpserver and it was amazingly easy. Pythons even got built in tls support, would that be doable in your server? Its not that necessary with reverse proxies but its still nice for hobby projects.
    • ashtonjamesd 2 hours ago
      Yes, I'm sure that is something I can add to it.

      I will add it to the backlog of things to do :)

  • EGreg 3 hours ago
    Take a look at https://www.reddit.com/r/programming/comments/225ovy/okws_ok...

    This was years ago (20 years ago?)

  • kahlonel 2 hours ago
    [dead]
  • yodon 3 hours ago
    [dead]
    • johnisgood 3 hours ago
      Use static analysis (Coverity, Coccinelle, sparse), enable KASAN/UBSAN, follow the SEI C Coding standard or MISRA C, and rely on the review process.

      Many popular C projects do really well. Projects that you probably use.

      Memory-safe languages eliminate vulnerability classes, but well-engineered C has proven viable for security-critical <insert whatever you want> infrastructure. The real question is whether the framework maintains that standard, not whether C is inherently unsuitable, thus the security concerns are legitimate but not absolute.

      I think you are being a bit too dismissive, and your comment puts nothing concrete on the table.

      • yodon 3 hours ago
        You CAN write good code in any language. The issue is, as you say, that memory-safe languages eliminate entire vulnerability classes, vulnerability classes that are among the most trivially exploitable.

        Can write safe code does not mean always writes safe code. A web server needs to be safe code, always.

        • hu3 2 hours ago
          This tired, flamewar-prone argument of gatekeeping new code in C/C++. Oh the irony coming from someone who wrote this some days ago:

          > One of the highest priorities for the HN algorithm is to promote good interactions and discourage bad interactions. The logic is if you have a lot of people bickering with each other, regardless of the topic, it normalizes bad behavior. HN is trying to sustain itself as a forum with great discussions.

          • yodon 2 hours ago
            I notice you chose to attack me rather than attacking the assertion that memory-safe languages are inherently safer than memory-unsafe languages like C. Yes, you CAN write memory safe code in C. You DO write memory safe code in languages like Java, Python, PHP, and C#. Critically, the maintenance programmer also writes memory safe code when working in a memory safe language. The maintenance programmer is not guaranteed to write memory safe code when working in a language like C.

            If any of the above is incorrect, I'm interested in learning more.

            • hu3 2 hours ago
              There's nothing to dispute in your assertion, because you're technically correct.

              However it's just not constructive and repetitive. You're basically walking into a bar and yelling that alcohol is unhealthy.

  • guerrilla 3 hours ago
    For fun or why?
    • ashtonjamesd 3 hours ago
      For fun! And because I wanted to create a framework that makes coding in C feel like a high level language (mainly for fun though).
    • hmry 3 hours ago
      Science isn't about why, it's about why not.
    • cozzyd 3 hours ago
      I think it makes lots of sense when adding e.g. a live view to some C daemon running on a single board computer. Obviously in these cases you're not generally on the public Internet and your clients are trusted.
  • camillomiller 3 hours ago
    Next up, a wordpress block editor in Cobol :)
    • Joeboy 3 hours ago
      A computer program written in a programming language.
    • osigurdson 2 hours ago
      Cobol and C are very different in terms of modern relevance.
    • alwahi 3 hours ago
      a saas in prolog...
      • wolfgangbabad 3 hours ago
        so basically vibecoding using gipiti prompting
      • sixtyj 3 hours ago
        Don’t forget Fortran… /s
  • alwahi 3 hours ago
    https://tenor.com/view/jeff-goldblum-jurassic-park-jurassic-...

    Your scientists were so preoccupied with whether or not they could that they didn't stop to think if they should....

    • ashtonjamesd 3 hours ago
      C finds a way.
    • firemelt 2 hours ago
      u should post this to people that write web with javascript
  • tobyhinloopen 3 hours ago
    Calling it a framework with an example that returns a hello world text response is a bit of a stretch, isn't it?
    • ashtonjamesd 2 hours ago
      Haha, the example could be better. All of the other things combined, I would say it could be called a framework.

      There are some more examples in doc/