From 00ba005e502b7d6762d9813eb554c7d7c9f44079 Mon Sep 17 00:00:00 2001
From: Markus Ylisiurunen <8409947+markusylisiurunen@users.noreply.github.com>
Date: Tue, 13 Jan 2026 19:29:36 +0200
Subject: [PATCH] set the prompt cache key to session id (#698)

---
 packages/ai/src/providers/openai-responses.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/ai/src/providers/openai-responses.ts b/packages/ai/src/providers/openai-responses.ts
index 72b53d9d..d1ffc9ce 100644
--- a/packages/ai/src/providers/openai-responses.ts
+++ b/packages/ai/src/providers/openai-responses.ts
@@ -366,6 +366,7 @@ function buildParams(model: Model<"openai-responses">, context: Context, options
 		model: model.id,
 		input: messages,
 		stream: true,
+		prompt_cache_key: options?.sessionId,
 	};
 
 	if (options?.maxTokens) {