ReferenceSDK ReferenceAnyStepDefinitionErased step definition type used when heterogeneous step arrays cross a package boundary.Copy MarkdownOpenSDK v2026.4.0 Kind: typeAlias Signature ExampleCopyexport type AnyStepDefinition = StepDefinitionAgentValidationErrorTyped error for SDK validation failures.ChatOutputDefinitionDeclarative contract selecting the chat-facing value from final step output.