diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index 6148b66b5..8b6bba903 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -598,6 +598,11 @@ export namespace ProviderTransform {
         result["reasoningSummary"] = "auto"
       }
     }
+
+    if (input.model.providerID === "venice") {
+      result["promptCacheKey"] = input.sessionID
+    }
+
     return result
   }