v4.12.22

honojs/honov4.12.22May 22, 2026by yusukebe

AI Summary

This patch release includes bug fixes for MIME type charset handling, compression encoding respect, and WebSocket subprotocol handling in Deno, along with adding msgpack as a new compressible content type.

Key Highlights

Added msgpack as a compressible content type
Fixed MIME type charset parameter to be specified per MIME type instead of mechanical detection
Fixed compression to respect Accept-Encoding header when encoding option is set
Fixed Deno WebSocket to echo negotiated subprotocol in upgrade response
Updated vitest to v4 with cleanup

New Features

Added msgpack as a compressible content type

Full Release Notes

## What's Changed
* chore: update vitest to v4 and cleanups by @BlankParticle in https://github.com/honojs/hono/pull/4952
* fix(mime): specify charset parameter per MIME type instead of mechanical detection by @renatograsso10 in https://github.com/honojs/hono/pull/4912
* fix(compress): respect Accept-Encoding when encoding option is set by @LeSingh1 in https://github.com/honojs/hono/pull/4951
* fix(deno): echo negotiated WebSocket subprotocol in upgrade response by @ATOM00blue in https://github.com/honojs/hono/pull/4955
* feat: add msgpack as a compressible content type by @na-trium-144 in https://github.com/honojs/hono/pull/4957

## New Contributors
* @renatograsso10 made their first contribution in https://github.com/honojs/hono/pull/4912
* @LeSingh1 made their first contribution in https://github.com/honojs/hono/pull/4951
* @ATOM00blue made their first contribution in https://github.com/honojs/hono/pull/4955
* @na-trium-144 made their first contribution in https://github.com/honojs/hono/pull/4957

**Full Changelog**: https://github.com/honojs/hono/compare/v4.12.21...v4.12.22