During August 2025, Oioki worked on security hardening for the OAuth approval flow in the getsentry/sentry-mcp repository. They integrated Hono’s CSRF protection middleware, replacing a custom CSRF solution with origin header validation to improve session integrity and reduce CSRF risk. Oioki also added security headers, including X-Frame-Options and Strict-Transport-Security, to strengthen defense-in-depth for the OAuth dialog. This backend development effort, implemented in TypeScript and JavaScript, enhanced the reliability and security of OAuth in production. The work demonstrated a focused approach to middleware integration and security best practices, addressing a critical area of authentication infrastructure.