From 5a8787dbeab188895ce2855620742e2e3e679760 Mon Sep 17 00:00:00 2001
From: mawkone <mark@getacquired.com>
Date: Mon, 1 Jun 2026 14:46:45 -0700
Subject: [PATCH] fix: parse thoughtSignature correctly to support
 reasoning-to-text promotion

---
 vibn-frontend/lib/ai/gemini-chat.ts | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/vibn-frontend/lib/ai/gemini-chat.ts b/vibn-frontend/lib/ai/gemini-chat.ts
index 71b578b6..b8f7f615 100644
--- a/vibn-frontend/lib/ai/gemini-chat.ts
+++ b/vibn-frontend/lib/ai/gemini-chat.ts
@@ -151,10 +151,13 @@ export async function callGeminiChat(opts: {
     const toolCalls: ToolCall[] = [];
 
     const parts = response.candidates?.[0]?.content?.parts ?? [];
+    const isPartThought = (p: Record<string, unknown>) =>
+      Boolean(p.thought || p.thoughtSignature);
 
     for (const part of parts) {
       if (part.text) {
-        if ((part as { thought?: unknown }).thought) thoughts += part.text;
+        if (isPartThought(part as Record<string, unknown>))
+          thoughts += part.text;
         else text += part.text;
       }
       if (part.functionCall) {
@@ -219,12 +222,14 @@ export async function* streamGeminiChat(opts: {
     });
 
     console.log("[GeminiChat] Stream request initiated");
+    const isPartThought = (p: Record<string, unknown>) =>
+      Boolean(p.thought || p.thoughtSignature);
 
     for await (const chunk of streamResult) {
       const parts = chunk.candidates?.[0]?.content?.parts ?? [];
       for (const part of parts) {
         if (part.text) {
-          yield (part as { thought?: unknown }).thought
+          yield isPartThought(part as Record<string, unknown>)
             ? { type: "thinking", text: part.text }
             : { type: "text", text: part.text };
         }