From e0b29de02da7b71b89cac35c929b81c6949d1994 Mon Sep 17 00:00:00 2001
From: lucas-barake <86905052+lucas-barake@users.noreply.github.com>
Date: Wed, 28 Jan 2026 19:54:20 -0500
Subject: [PATCH] Wrap primitive tool results in object for Gemini API
 compatibility

---
 .changeset/fix-google-primitive-tool-results.md | 5 +++++
 packages/ai/google/src/GoogleLanguageModel.ts   | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/fix-google-primitive-tool-results.md

diff --git a/.changeset/fix-google-primitive-tool-results.md b/.changeset/fix-google-primitive-tool-results.md
new file mode 100644
index 00000000000..97194ea175c
--- /dev/null
+++ b/.changeset/fix-google-primitive-tool-results.md
@@ -0,0 +1,5 @@
+---
+"@effect/ai-google": patch
+---
+
+Wrap primitive tool results in an object before sending to Gemini
diff --git a/packages/ai/google/src/GoogleLanguageModel.ts b/packages/ai/google/src/GoogleLanguageModel.ts
index 760022de4bd..adf1effc39b 100644
--- a/packages/ai/google/src/GoogleLanguageModel.ts
+++ b/packages/ai/google/src/GoogleLanguageModel.ts
@@ -386,11 +386,12 @@ const prepareMessages: (
           const parts: Array<typeof Generated.Part.Encoded> = []
 
           for (const part of message.content) {
+            const response = Predicate.isRecord(part.result) ? part.result : { result: part.result }
             parts.push({
               functionResponse: {
                 id: part.id,
                 name: part.name,
-                response: part.result as any
+                response: response as any
               }
             })
           }