v1.64.0 (2026-03-02)

What's Changed

🚀 Features

• feat: support template=False on PromptedOutput and NativeOutput to disable schema prompt by @DouweM in #4497

🐛 Bug Fixes

• Fix missing run_id on ModelRequest in UI adapter runs by @madanlalit in #4419
• Wrap Google streaming errors as ModelHTTPError/ModelAPIError by @saakshigupta2002 in #4437
• fix(mcp): move __aexit__ guard inside lock to prevent TOCTOU race by @jameslcowan in #4435
• fix: BaseToolCallPart.has_content() incorrectly returns False for falsy arg values by @bsherifi in #4442
• fix(anthropic): auto-fallback to streaming for high max_tokens by @DouweM in #4496
• fix(vercel): Align dump_messages output with Vercel spec by @dsfaccini in #4196
• fix: cancel sibling tasks on any exception in parallel tool execution by @LakshmiSravyaVedantham in #4502

New Contributors

• @jameslcowan made their first contribution in #4435
• @bsherifi made their first contribution in #4442
• @LakshmiSravyaVedantham made their first contribution in #4502

Full Changelog: v1.63.0...v1.64.0