Sean McArthur
@seanmonstar.com
Open Source maintainer of the rust-lang @hyper.rs. More at seanmonstar.com
New #rustlang hyper v1.12.0 released today! 🦀 🚀 github.com/hyperium/hyp...
Release v1.12.0 · hyperium/hyper
Features http1: add max_header_size limit for server and client (#4183) (d1cd14ef, closes #3832) Bug Fixes http1: withdraw a stale want when the client dispatcher takes a request (#4208) (c44f1...
github.com
New #rustlang hyper-util v0.1.21 out now! - Adds several builder options - Fixes for CONNECT, proxies, idle connections, and a bunch more - Adjusts the tracing behavior of the legacy::Client github.com/hyperium/hyp...
Release v0.1.21 · hyperium/hyper-util
Additions Add crate-level documentation. (#327) Add client::legacy::Builder::http2_header_table_size() method. (#274) Add client::legacy::Builder::http2_max_concurrent_streams() method. (#274) Add...
github.com
Reading LLM text makes us worse writers Originally at https://seanmonstar.com/micro/20260917-reading-llms-worsens-writing/
Reading LLM text makes us worse writers
The top advice given to anyone wanting to get better at writing, besides just writing, is to _read_ more. Especially good writing. Because we imitate that which we experience more of.
seanmonstar.com
We've been cooking at @ersc.io "What comes after git" ersc.io/blog/what-co...
What comes after git
Our thoughts about the future of version control
ersc.io
rustls, our modern memory-safe TLS implementation is 10 years old! @jbp.io wrote a blog post reflecting on how we got here: rustls.dev/blog/2026-09...
rustls: A Decade of Rustls
rustls.dev
HIPs: hyper Improvement Proposals Originally at https://seanmonstar.com/micro/20260902-hips/
HIPs: hyper Improvement Proposals
A short intro for now: since hyper stabilized 1.0, it powers more, and needs more. Large improvements lacked a clear path for proposal, scrutiny, and decision. So, hyper Improvement Proposals (https://hyper.rs/contrib/hips/0001-hyper-improvement-proposals/), or HIPs.
seanmonstar.com
Welcoming Jess Izen as our new Engineer in Residence! For the next year she'll work with our team (while staying at AWS) on crates.io security and support for #rustlang community libraries, starting with malicious crate detection for new publishes! 🦀 Learn more: rustfoundation.org/media/welcom...
Using LLMs to find not-that-rock Originally at https://seanmonstar.com/micro/20260825-llms-not-that-rock/
Using LLMs to find not-that-rock
Imagine someone tells you to get them a rock. You go find one, bring it back, and they reply 'no, not that rock'. They didn't know exactly what they wanted, but they knew yours wasn't it.
seanmonstar.com
New blog post: Tending my little plot of the internet Basically, the subscribe-via-email is much better, and there is now a self-hosted microblog. seanmonstar.com/blog/owning-...
Tending my little plot of the Internet
As many parts of the Internet continue to get worse, I figured it was time to improve my own little plot.
seanmonstar.com
New #rustlang h2 release v0.4.16 out today! - Enforce limits on tiny DATA frames. (GHSA-q83h-524g-xf6h) - Significant performance improvements: IO contention and HPACK decoding. - Several smaller fixes. Worth an upgrade! github.com/hyperium/h2/...
Release v0.4.16 · hyperium/h2
What's Changed fix: error instead of busy-looping when write returns Ok(0) by @ArniDagur in #921 Revert "perf(header): optimize HeaderValue creation via zero-copy sharing" by @0x676e67 in #924 fix...
github.com
Rust CI now runs cargo-semver-checks to prevent accidental breakage in the standard library 🦀 If you're wondering why that's important and why it took 15kLoC+, this post is for you. predr.ag/blog/protect...
Protecting the Rust standard library from accidental breakage
How & why we're running cargo-semver-checks in Rust's CI
predr.ag
A trait for fluent Durations Originally at https://seanmonstar.com/micro/20260812-trait-fluent-durations/
A trait for fluent Durations
I dislike the pattern in some languages to create durations by multiplying constants. It feels like a concession when it cannot be expressed more nicely. There's a tracking issue (https://triagebot.infra.rust-lang.org/gh-comments/rust-lang/rust/issues/57391) to add such constants in libstd.
seanmonstar.com
New #rustlang http v1.5.0 out now! Support for the new `QUERY` method from RFC 10008! And of course bug fixes. github.com/hyperium/htt...
Release v1.5.0 · hyperium/http
What's Changed feat(method): add QUERY method by @seanmonstar in #798 fix(uri): allow empty paths in uri::Builder by @seanmonstar in #853 perf(header,uri): faster value validation, URI parse/forma...
github.com
I want your own words Originally at https://seanmonstar.com/micro/20260729-i-want-your-own-words/
I want your own words
If you choose to communicate with me, all I ask is that you use your own words. Bug reports and issues. Pull request descriptions and especially review comments. This isn't new, but I wanted a link of my own.
seanmonstar.com
Do you ever write a sentence and send it, and then read it back to yourself and think, "oh no, I'm an LLM".
Three years ago, trying to use Rust for web apps was crazy talk. Today is very different than three years ago. Announcing Topcoat, a batteries-included Rust framework for building reactive web applications: tokio.rs/blog/2026-07...
Announcing Topcoat: a framework for building full-stack reactive web apps with Rust | Tokio - An asynchronous Rust runtime
Tokio is a runtime for writing reliable asynchronous applications with Rust. It provides async I/O, networking, scheduling, timers, and more.
tokio.rs
Accessors can reveal internal representation Originally at https://seanmonstar.com/micro/20260721-accessors-reveal-internal-repr/
New release of #rustlang hyper out today, v1.11.0! 🚀 Several big bug fixes. - Buffered data fully flushes even when half closed - Enforce backpressure in HTTP/2 Upgraded bodies (like CONNECT) - Start of a strict Clippy allowlist - 10 contributors, 7 of them new! 🦀 github.com/hyperium/hyp...
Release v1.11.0 · hyperium/hyper
Features rt: add ReadBufCursor::initialized_unfilled() method (#4115) (ccc1e850) Bug Fixes http1: discard content-length header when received before transfer-encoding (#4124) (540fff91, closes ...
github.com
Rust Errors generally shouldn't be PartialEq Originally at https://seanmonstar.com/micro/20260713-errors-not-partialeq/
Do you use #rustlang hyper/h2 at scale? Would you be able to easily try out a performance run using a PR that is meant to significantly reduce contention with multi-threaded HTTP/2? It would be a big help! github.com/hyperium/h2/...
Refactor big mutex to reduce contention by seanmonstar · Pull Request #917 · hyperium/h2
This refactor puts the big internal shared mutex on a diet. The goal is to reduce contention, providing performance improvements when h2 is used on multi-threaded runtimes. WarningThis is a large i...
github.com
Do you use #rustlang hyper/h2 at scale? Would you be able to easily try out a performance run using a PR that is meant to significantly reduce contention with multi-threaded HTTP/2? It would be a big help! github.com/hyperium/h2/...
Refactor big mutex to reduce contention by seanmonstar · Pull Request #917 · hyperium/h2
This refactor puts the big internal shared mutex on a diet. The goal is to reduce contention, providing performance improvements when h2 is used on multi-threaded runtimes. WarningThis is a large i...
github.com
[NEWS] The Rust Foundation has launched the Rust Commercial Network: a free, open community for orgs building Rust in production to collaborate & share real-world use-cases with the Rust Project. Founding members span big tech, Rust specialists, & community orgs. rustfoundation.org/media/rust-c...
Owning my microblog with POSSE Originally at https://seanmonstar.com/micro/2026/06/23/owning-my-microblog-with-posse/
New #rustlang h2 v0.4.15 out now! 🚀 Includes several bug fixes for capacity, resets, and more. github.com/hyperium/h2/...
Release v0.4.15 · hyperium/h2
What's Changed fix: Discard buffered DATA when a scheduled reset is pending by @ArniDagur in #896 fix: poll_capacity must not return Ready(Some(Ok(0))) by @ArniDagur in #898 fix: Reject frames on ...
github.com
To put it another way: if the official position of the Android and Linux kernel teams is “we, some of the world’s best coders, can’t safely use C” then the bar under CRA’s requirements of “safe by design” should be nearly impossible to meet for mere mortals when using C.
The TokioConf 2026 talks are now available on YouTube: youtube.com/playlist?lis.... Also, TokioConf 2027 will be April 26 & 27, 2027 in Portland, OR. Save the date!
TokioConf 2026 - YouTube
Organized by the Tokio team to facilitate networking and knowledge exchange among engineers tackling similar challenges in Rust. A dedicated conference for d...
youtube.com
Rust 1.96.0 has been released! 🌈 🦀✨ This release includes assert_matches!(), new range types in core::range::*, and fixes for a medium and a low severity vulnerability in Cargo (that didn't affect crates.io users). Check out the blog post for details: blog.rust-lang.org/2026/05/28/R...
Announcing Rust 1.96.0 | Rust Blog
Empowering everyone to build reliable and efficient software.
blog.rust-lang.org
Out now, new #rustlang hyper v1.10.0! - New HTTP/2 builder options. - Fix for HTTP/2 capacity usage. - Fix for HTTP/1 bodies if the future drops unexpectedly. - Other refactors to improve code cleanliness. github.com/hyperium/hyp...
Release v1.10.0 · hyperium/hyper
Features http2: add reset_stream_duration() client option (#4068) (156a6f6a, closes #2599) Add 'header_table_size()' method to server builder (#4062) (6c9182c4) Bug Fixes http1: send error ...
github.com
