v4.21.1 v4.21.2

Name: fastmcp
Author: punkpeye

punkpeye/fastmcpSep 25, 2026 → Sep 25, 20260 days between releases

Generating AI comparison

Analyzing what changed between v4.21.1 and v4.21.2. This page updates automatically — usually within a minute.

The Two Releases

v4.21.1

Sep 25, 2026· 27 days ago

A maintenance release addressing various bugs, including incorrect error codes for unknown prompts, hanging validation commands, and type-checking issues. It ensures proper access control for authenticated stdio sessions.

Full release notes

v4.21.2

Sep 25, 2026· 27 days ago

Focuses on refining tool input schemas and error handling. It fixes errors for unknown resources, ensures free-form arguments are handled correctly, and improves security by hiding unauthorized tools.

Full release notes