OutputMessageItemPhaseUnion Type | OpenRouter Go SDK | OpenRouter

The Go SDK and docs are currently in beta. Report issues on GitHub.

The phase of an assistant message. Use commentary for an intermediate assistant message and final_answer for the final assistant message. For follow-up requests with models like gpt-5.3-codex and later, preserve and resend phase on all assistant messages. Omitting it can degrade performance. Not used for user messages.

Supported Types

OutputMessageItemPhaseCommentary

1 outputMessageItemPhaseUnion := components.CreateOutputMessageItemPhaseUnionOutputMessageItemPhaseCommentary(components.OutputMessageItemPhaseCommentary{/* values here */})

OutputMessageItemPhaseFinalAnswer

1 outputMessageItemPhaseUnion := components.CreateOutputMessageItemPhaseUnionOutputMessageItemPhaseFinalAnswer(components.OutputMessageItemPhaseFinalAnswer{/* values here */})

1 outputMessageItemPhaseUnion := components.CreateOutputMessageItemPhaseUnionAny(any{/* values here */})

Union Discrimination

Use the Type field to determine which variant is active, then access the corresponding field:

1 switch outputMessageItemPhaseUnion.Type {
2 	case components.OutputMessageItemPhaseUnionTypeOutputMessageItemPhaseCommentary:
3 		// outputMessageItemPhaseUnion.OutputMessageItemPhaseCommentary is populated
4 	case components.OutputMessageItemPhaseUnionTypeOutputMessageItemPhaseFinalAnswer:
5 		// outputMessageItemPhaseUnion.OutputMessageItemPhaseFinalAnswer is populated
6 	case components.OutputMessageItemPhaseUnionTypeAny:
7 		// outputMessageItemPhaseUnion.Any is populated
8 }