isOpenAIResponsesModel

function isOpenAIResponsesModel(model): boolean;

Detect an OpenAI Responses-API model. The Responses API supports truncation: 'auto' (server-side context-overflow safety net) and promptCacheKey (per-session cache routing). Both flow through AI SDK v6’s providerOptions.openai.

Matches:

• provider === ‘openai’ (direct + OpenRouter pass-through “openai/…”)
• modelId on the Responses family (gpt-4o, gpt-4.1, gpt-5, o3, o4-mini, etc.)

Conservative: when in doubt, returns false (it’s safer to skip the provider option than to send a 400-causing field to a non-OpenAI provider).

Parameters

Parameter	Type
model	unknown

Returns

boolean