fix(core): Discard thought signature when switching from Gemini API Key to OAuth (#6090)

Co-authored-by: Jacob Richman <[email protected]>

1 files changed, 9 insertions, 1 deletions

diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index 7c61f239..5c11667b 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -379,13 +379,21 @@ export class Config {
     const newGeminiClient = new GeminiClient(this);
     await newGeminiClient.initialize(newContentGeneratorConfig);
 
+    // Vertex and Genai have incompatible encryption and sending history with
+    // throughtSignature from Genai to Vertex will fail, we need to strip them
+    const fromGenaiToVertex =
+      this.contentGeneratorConfig?.authType === AuthType.USE_GEMINI &&
+      authMethod === AuthType.LOGIN_WITH_GOOGLE;
+
     // Only assign to instance properties after successful initialization
     this.contentGeneratorConfig = newContentGeneratorConfig;
     this.geminiClient = newGeminiClient;
 
     // Restore the conversation history to the new client
     if (existingHistory.length > 0) {
-      this.geminiClient.setHistory(existingHistory);
+      this.geminiClient.setHistory(existingHistory, {
+        stripThoughts: fromGenaiToVertex,
+      });
     }
 
     // Reset the session flag since we're explicitly changing auth and using default model