v1.22.0 (2025-11-21)

What's Changed

• Add OpenRouterModel as OpenAIChatModel subclass with additional feature support by @ajac-zero in #3089
• Make FallbackModel fall back on all model API errors, not just HTTP status 400+ by @dsfaccini in #3494
• Don't skip model request when history ends on response but there are new instructions by @DouweM in #3509
• Revert "feat: enforce message history starts with user message" by @DouweM in #3508
• Don't send Google messages with 0 parts by @DouweM in #3511
• Immediately raise error when response is empty because of token limit by @DouweM in #3512
• Relax UserError into a warning when state deps is not provided with AG-UI by @MikeRyanDev in #3510
• Add type stubs for some third-party libraries by @lars20070 in #3443
• Add document to allowed cacheable_types for anthropic by @marpulli in #3513
• Don't insert empty ThinkingPart when Google response ends in text with thought_signature by @DouweM in #3516
• Fix deprecated GeminiModel structured output and tool call thought signatures by @DouweM in #3517

New Contributors

• @marpulli made their first contribution in #3513

Full Changelog: v1.21.0...v1.22.0