Libevent Session (Bitcoin Core Dev Tech, May 2026)

Two efforts are converging to remove libevent, the aging C networking library Bitcoin Core uses for HTTP (tracked in issue #31194). The larger effort replaces the HTTP server (PR #35182, with backstory in the 100-comment #32061), and a separate PR adds a lightweight HTTP client for the CLI (#34342). The CLI change looks likely to merge first; both could merge independently, with header handling unified in a later release.

The rationale is that libevent is old and historically crash-prone — a fix for a known crash was merged upstream but never released — and that implementing an in-house HTTP server is reasonable because the interface is not meant to be exposed publicly (RPC should sit behind a reverse proxy like nginx, and even REST has historically been unsafe to expose directly). Both PRs are reportedly getting good review, with downstream testing (for example against LND) underway, and a final cleanup PR to remove libevent expected to follow naturally.