Thanks for looking, and yes, I can rename it. Will do today. Also, thanks for the excellent protocol. In this entire "effort", I only found one ambiguity in it (and reported it in your repo). Everything about it was well defined and succinct. The pipelining is really useful.
OP here. :-) (feel like I should put an emoji here). My focus as I "built" this was getting to a correct implementation, and putting in place guards and context to achieve that. As I moved through the process I added more and more ways to eval progress toward that. An area I didn't invest any of my effort in was commit messages, and some of them caused me to spit take as I saw them go by. I think this is something that can definitely be improved, and this conversation is fuel for thought on how to do this.
Thank you. Along the way in doing this I spent most of my effort in providing guard rails to eliminate or reduce slop. My goal was something I can use in other pet projects and maintain. I'm satisfied with the outcome, and appreciate you noticing it wasn't just yolo vibe coding.
OP here. I frankly stopped trying to add evals for the "ready for production" happiness Claude is trained to produce. I agree, not ready for production. I did though put a intention and effort into guarding against slop in implementation and tests. Sure I can still find it, but I believe the current state is solid enough to build on, and I will be doing so for some pet projects. I'll let you know what I find when using it in anger.
That is was boring is what appealed to me. That is was also thought through with rigor was the other part. I wanted something to use in some pet projects, in rust, so having an implementation of the "wrangling" code I could reuse was value to me. Learning how to put guardrails on sing an LLM productively was another.
OP here. Thanks for all the thoughtful feedback, I really appreciate it.
I mentioned in the README that I leaned heavily on Claude Opus for the port. One of the biggest challenges was tamping down its default “everything is production-ready in a week” optimism. That said, I also discovered along the way which guardrails worked and which didn’t for guiding it toward a compliant implementation. It was good learning, and honestly, fun.
I’m genuinely interested in the Cap’n Web protocol. Writing this in Rust gave me a much clearer sense of where I would and wouldn’t use it. Credit to the Cloudflare team for defining the protocol and shipping a solid reference implementation, this wouldn’t have been possible otherwise.
A good example of why a second client (even one bootstrapped with AI) is useful: in implementation I ran into a spec ambiguity around array escaping (documented here: https://github.com/cloudflare/capnweb/issues/68
). My initial Rust serializer emitted unescaped arrays at lower levels, and I even patched the TS reference to accept them. In the end, escaping arrays at all levels turned out to be the cleaner and more consistent approach, so I’ve recommended that clarification in the issue.
On naming: fair point about possible confusion with Cap’n Proto. If the Cloudflare team ever wants the crate names for an official Rust impl, they’re theirs. If there’s interest in pushing this to production ready quality, I’d also be glad to put in the work.
Thanks again for the constructive input. Happy to dive into technical details if folks are curious.
I'm happy to make the name available to later implementations with committed resources, and I definitely welcome contributions to this implementation if you find it useful. This week I'm going to try building a for pet projects on it and will likely make some changes to improve this.
did you use lates claude release? did you ask codex to review and bug fix? what wat time spent promting, manual fixes and waiting for agent to finish work?
