The release raises the httpx2 minimum from 2.5 to 2.10 and makes invalid x-mcp-header registration fail with InvalidSignature instead of silently dropping it. Check your dependency lock and run the server registration path that declares custom headers. A startup/registration fixture is more relevant here than an invented performance comparison.
Context reviewed 2026-10-16 against the original release notes ↗. This is guidance for the version above, not a claim that it is the latest release.