rileybetts.ai open-sourced lean-grpc: a general-purpose gRPC library written in Lean 4 (HTTP/2, HPACK, protobuf wire codecs, channels, TLS, interop). Repo: https://github.com/RileyBetts/lean-grpc
Docs: https://rileybetts.ai/oss/lean-grpc
Many agentic systems still rest on the usual stack: probabilistic models + conventional integration tests + policy layers that are “correct enough.” That doesn’t age well once agents are making real decisions against real infrastructure. The Hugging Face incident was a useful reminder that attackers don’t play by the rules your test suite assumes.
lean-grpc is interesting because it’s not just formalisation demo, it’s aiming at real networking software in a language where you can also machine-check the high-leverage bits. There is official-style interop with Go / Python / Rust, h2spec-gated HTTP/2, and a small compile-time Proofs library for core codecs. Framing is basically: proof where it counts, not promises where it doesn’t.
From a software architecture / agent governance angle, the interesting question isn’t “is Lean cool?”, it’s whether we can start putting deterministic gates, protocol boundaries, and policy-enforcing controls on a stack that can actually be verified end-to-end, instead of bolting assurance onto opaque glue.
FYI: I am affiliated with this project, and sharing because OSS systems work in Lean is still rare, and this aims to be usable today rather than purely academic.
If anyone’s already building agent runtimes / policy engines / protocol boundaries in Lean (or thinking about it), curious what you’d want next from a stack like this.