Hono 4.12.32

Hono 4.12.32 has been released on July 24, 2026 — a focused patch release that brings important fixes to AWS Lambda integration, SSE handling, and security headers.

What's Fixed in Hono 4.12.32

This release is primarily a bugfix and quality-of-life update. Here are the key changes:

• AWS Lambda improvements — Added JWT and Lambda authorizer types for API Gateway v2, making it easier to build serverless apps with Hono on AWS.
• SSE (Server-Sent Events) fix — The SSE middleware now correctly emits an empty id field to reset the Last-Event-ID, fixing a subtle streaming issue.
• Query parsing safety — Hono now uses Object.create(null) when parsing query strings, headers, and params, preventing prototype pollution vulnerabilities.
• Secure headers scope fix — CSP callbacks in the secure-headers middleware are now properly scoped to their respective header, ensuring correct Content Security Policy configuration.
• WebSocket adapter tests — Added comprehensive test coverage for the Cloudflare Workers WebSocket adapter, covering onClose, onError, send, and close paths.
• CI improvements — Enabled reports for type checking and bundle size in the CI pipeline, helping catch regressions earlier.

Upgrade Now

Hono 4.12.32 is available on npm. Update with bun update hono, npm install hono@latest, or pnpm add hono@latest.

As always, check the full changelog on GitHub for the complete list of changes. If you're already on 4.12.x, this is a low-risk, recommended upgrade.