v4.12.31

honojs/honov4.12.31Jul 18, 2026by yusukebe

AI Summary

Bug fixes for response header helpers, multipart request handling, and SSE retry logic. It also adds app.fetch() overhead benchmarks.

Key Highlights

Fixed case-insensitive header names in response helpers.
Added app.fetch() overhead benchmark.
Fixed multipart boundary mismatch in `cloneRawRequest`.
Fixed SSE retry field emission when retry is `0`.

Full Release Notes

## What's Changed
* test(context): assert case-insensitive header names in response helpers by @yusukebe in https://github.com/honojs/hono/pull/5116
* chore(benchmark): add app.fetch() overhead benchmark by @yusukebe in https://github.com/honojs/hono/pull/5117
* refactor(aws-lambada): remove FIXME in `@ts-expect-error` by @yusukebe in https://github.com/honojs/hono/pull/5130
* fix(utils/body): reuse cached formData in `parseBody()` by @yusukebe in https://github.com/honojs/hono/pull/5131
* fix(request): fix multipart boundary mismatch in `cloneRawRequest` by @yusukebe in https://github.com/honojs/hono/pull/5133
* fix(sse): emit retry feild when retry is `0` by @yusukebe in https://github.com/honojs/hono/pull/5135
* test(validator): fix misspelled identifier in transform type test by @yusukebe in https://github.com/honojs/hono/pull/5136

**Full Changelog**: https://github.com/honojs/hono/compare/v4.12.30...v4.12.31