🍌 feat: Gemini Image Generation Tool (Nano Banana) (#10676)

* Added fully functioning Agent Tool supporting Google's Nano Banana

* 🔧 refactor: Update Google credentials handling in GeminiImageGen.js

* Refactored the credentials path to follow a consistent pattern with other Google service integrations, allowing for an environment variable override.
* Updated documentation in README-GeminiNanoBanana.md to reflect the new credentials handling approach and removed references to hardcoded paths.

* 🛠️ refactor: Remove unnecessary whitespace in handleTools.js

* 🔧 feat: Update Gemini Image Generation Tool

- Bump @google/genai package version to ^1.19.0 for improved functionality.
- Refactor GeminiImageGen to createGeminiImageTool for better clarity and consistency.
- Enhance manifest.json for Gemini Image Tools with updated descriptions and icon.
- Add SVG icon for Gemini Image Tools.
- Implement progress tracking for Gemini image generation in the UI.
- Introduce new toolkit and context handling for image generation tools.

This update improves the Gemini image generation capabilities and user experience.

* 🗑️ chore: Remove outdated Gemini image generation PNG and update SVG icon

- Deleted the obsolete PNG file for Gemini image generation.
- Updated the SVG icon with a new design featuring a gradient and shadow effect, enhancing visual appeal and consistency.

* fix: ESLint formatting and unused variable in GeminiImageGen

* fix: Update default model to gemini-2.5-flash-image

* ✨ feat: Enhance Gemini Image Generation Configuration

- Updated .env.example to include new environment variables for Google Cloud region, service account configuration, and Gemini API key options.
- Modified GeminiImageGen.js to support both user-provided API keys and Vertex AI service accounts, improving flexibility in client initialization.
- Updated manifest.json to reflect changes in authentication methods for the Gemini Image Tools.
- Bumped @google/genai package version to 1.19.0 in package-lock.json for compatibility with new features.

* 🔧 fix: Format Default Service Key Path in GeminiImageGen.js

- Adjusted the return statement in getDefaultServiceKeyPath function for improved readability by formatting it across multiple lines. This change enhances code clarity without altering functionality.

* ✨ feat: Enhance Gemini Image Generation with Token Usage Tracking

- Added `recordTokenUsage` function to track token usage for balance management.
- Integrated token recording into the image generation process.
- Updated Gemini image generation tool to accept optional `aspectRatio` and `imageSize` parameters for improved image customization.
- Updated token values for new Gemini models in the transaction model.
- Improved documentation for image generation tool descriptions and parameters.

* ✨ feat: Add new Gemini models for image generation token limits

- Introduced token limits for 'gemini-3-pro-image' and 'gemini-2.5-flash-image' models.
- Updated token values to enhance the Gemini image generation capabilities.

* 🔧 fix: Update Google Service Key Path for Consistency in Initialization (#11001)

* 🔧 refactor: Update GeminiImageGen for improved file handling and path resolution

- Changed the default service key path to use process.cwd() for better compatibility.
- Replaced synchronous file system operations with asynchronous promises for mkdir and writeFile, enhancing performance and error handling.
- Added error handling for credential file access to prevent crashes when the file does not exist.

* 🔧 refactor: Update GeminiImageGen to streamline API key handling

- Refactored API key checks to improve clarity and consistency.
- Removed redundant checks for user-provided keys, enhancing code readability.
- Ensured proper logging for API key usage across different configurations.

* 🔧 fix: Update GeminiImageGen to handle imageSize support conditionally

- Added a check to ensure imageSize is only applied if the gemini model does not include 'gemini-2.5-flash-image', improving compatibility.
- Enhanced the logic for setting imageConfig to prevent potential issues with unsupported configurations.

* 🔧 refactor: Simplify local storage condition in createGeminiImageTool function

* 🔧 feat: Enhance image format handling in GeminiImageGen with conversion support

* 🔧 refactor: Streamline API key initialization in GeminiImageGen

- Simplified the handling of API keys by removing redundant checks for user-provided keys.
- Updated logging to reflect the new priority order for API key usage, enhancing clarity and consistency.
- Improved code readability by consolidating key retrieval logic.

---------

Co-authored-by: Dev Bhanushali <dev.bhanushali@hingehealth.com>
Co-authored-by: Danny Avila <danny@librechat.ai>

.env.example

@@ -185,8 +185,16 @@ GOOGLE_KEY=user_provided
 
 # GOOGLE_TITLE_MODEL=gemini-2.0-flash-lite-001
 
+# Google Cloud region for Vertex AI (used by both chat and image generation)
 # GOOGLE_LOC=us-central1
 
+# Alternative region env var for Gemini Image Generation
+# GOOGLE_CLOUD_LOCATION=global
+
+# Vertex AI Service Account Configuration
+# Path to your Google Cloud service account JSON file
+# GOOGLE_SERVICE_KEY_FILE=/path/to/service-account.json
+
 # Google Safety Settings
 # NOTE: These settings apply to both Vertex AI and Gemini API (AI Studio)
 #
@@ -206,6 +214,27 @@ GOOGLE_KEY=user_provided
 # GOOGLE_SAFETY_DANGEROUS_CONTENT=BLOCK_ONLY_HIGH
 # GOOGLE_SAFETY_CIVIC_INTEGRITY=BLOCK_ONLY_HIGH
 
+#========================#
+# Gemini Image Generation #
+#========================#
+
+# Gemini Image Generation Tool (for Agents)
+# Supports multiple authentication methods in priority order:
+# 1. User-provided API key (via GUI)
+# 2. GEMINI_API_KEY env var (admin-configured)
+# 3. GOOGLE_KEY env var (shared with Google chat endpoint)
+# 4. Vertex AI service account (via GOOGLE_SERVICE_KEY_FILE)
+
+# Option A: Use dedicated Gemini API key for image generation
+# GEMINI_API_KEY=your-gemini-api-key
+
+# Option B: Use Vertex AI (no API key needed, uses service account)
+# Set this to enable Vertex AI and allow tool without requiring API keys
+# GEMINI_VERTEX_ENABLED=true
+
+# Vertex AI model for image generation (defaults to gemini-2.5-flash-image)
+# GEMINI_IMAGE_MODEL=gemini-2.5-flash-image
+
 #============#
 # OpenAI     #
 #============#