From 7167f193c02520440420a8e88099620fc81b8470 Mon Sep 17 00:00:00 2001
From: Oleksiy Syvokon <oleksiy@zed.dev>
Date: Tue, 12 Aug 2025 21:51:23 +0300
Subject: [PATCH] open_ai: Send `prompt_cache_key` to improve caching (#36065)

Release Notes:

- N/A

Co-authored-by: Michael Sloan <mgsloan@gmail.com>
---
 crates/language_models/src/provider/open_ai.rs | 1 +
 crates/open_ai/src/open_ai.rs                  | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/crates/language_models/src/provider/open_ai.rs b/crates/language_models/src/provider/open_ai.rs
index 2879b01ff3..9eac58c880 100644
--- a/crates/language_models/src/provider/open_ai.rs
+++ b/crates/language_models/src/provider/open_ai.rs
@@ -473,6 +473,7 @@ pub fn into_open_ai(
         } else {
             None
         },
+        prompt_cache_key: request.thread_id,
         tools: request
             .tools
             .into_iter()
diff --git a/crates/open_ai/src/open_ai.rs b/crates/open_ai/src/open_ai.rs
index a6fd03a296..919b1d9ebf 100644
--- a/crates/open_ai/src/open_ai.rs
+++ b/crates/open_ai/src/open_ai.rs
@@ -244,6 +244,8 @@ pub struct Request {
     pub parallel_tool_calls: Option<bool>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub tools: Vec<ToolDefinition>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub prompt_cache_key: Option<String>,
 }
 
 #[derive(Debug, Serialize, Deserialize)]