SDKs

Speakeasy Ruby SDKs now support Ruby 4.0

Brian Flad

January 8, 2026 - 1 min read

SDKs

Language runtime upgrades happen regularly, and each one requires testing, compatibility fixes, and releases. With Speakeasy, this work happens automatically. Ruby 4.0 dropped on December 25, 2025, and as of today, we’ve updated our generators and perform compatibility tests so you don’t have to. Your users get uninterrupted support for the latest Ruby version, and your team stays focused on your core product.

What changed in Ruby 4.0

Ruby 4.0 was released on December 25, 2025, bringing exciting new features like Ruby Box for isolated definition spaces, the experimental ZJIT compiler, core language improvements including Set and Pathname promoted to core classes, as well as some general language clean up:

Removal of deprecated Ractor methods (Ractor.yield, Ractor#take)
Changes to *nil behavior (no longer invokes nil.to_a)
Removal of process creation via IO/Kernel#open with leading |
Various stdlib changes including CGI library removal from defaults

None of these affected our generated SDKs significantly, but we verified compatibility so you don’t have to wonder.

Get started

If you’re already using Speakeasy to generate Ruby SDKs, you’re all set. Regenerate your SDK using the latest Speakeasy version to pick up the improvements.

If you’re maintaining Ruby SDKs manually and want to stop worrying about runtime compatibility, get started with Speakeasy .

Last updated on January 12, 2026