SUPPORT PERSISTENT REASONING EFFORT

Summary from the TLDR AI newsletter

Codex has added 'persistent' to the reasoning-effort protocol and TypeScript SDK types. When a user targets a custom Responses-compatible provider whose model-defined effort is literally persistent, this now deserializes to the new Persistent variant and is unconditionally rewritten to disabled. Previously, it remained Custom("persistent") and was forwarded unchanged. Existing configurations and resumed sessions can therefore send a different value and change behavior or be rejected, so this alias should be limited to providers that define the translation.