Adds 'minimal' and 'metadata' format options for get_gmail_thread_content and get_gmail_threads_content_batch

README.md

@@ -716,14 +716,34 @@ cp .env.oauth21 .env
 | `get_gmail_messages_content_batch` | **Core** | Batch retrieve message content |
 | `send_gmail_message` | **Core** | Send emails |
 | `get_gmail_thread_content` | Extended | Get full thread content |
+| `get_gmail_thread_metadata` | Extended | Get thread metadata (headers, labels, snippet) |
 | `modify_gmail_message_labels` | Extended | Modify message labels |
+| `modify_gmail_thread_labels` | Extended | Modify labels for all messages in a thread |
 | `list_gmail_labels` | Extended | List available labels |
 | `manage_gmail_label` | Extended | Create/update/delete labels |
 | `draft_gmail_message` | Extended | Create drafts |
 | `get_gmail_threads_content_batch` | Complete | Batch retrieve thread content |
+| `get_gmail_threads_metadata_batch` | Complete | Batch retrieve thread metadata |
 | `batch_modify_gmail_message_labels` | Complete | Batch modify labels |
+| `batch_modify_gmail_thread_labels` | Complete | Batch modify labels for all messages in threads |
 | `start_google_auth` | Complete | Initialize authentication |
 
+**Gmail Message Format Options:**
+
+Both `get_gmail_thread_content` and `get_gmail_threads_content_batch` support an optional `format` parameter (defaults to `"full"`):
+
+| Format | Description |
+|--------|-------------|
+| `"minimal"` | Returns only the `id` and `threadId` of each message. |
+| `"metadata"` | Returns message metadata such as headers, labels, and snippet, but *not* the full body. |
+| `"full"` | Returns the full email message data, including headers and body (Base64 encoded). This is the default and most commonly used for reading messages. |
+
+**Convenience Metadata Functions:**
+
+For quick access to metadata only, use the dedicated metadata functions:
+- `get_gmail_thread_metadata` - Equivalent to `get_gmail_thread_content` with `format="metadata"`
+- `get_gmail_threads_metadata_batch` - Equivalent to `get_gmail_threads_content_batch` with `format="metadata"`
+
 </td>
 <td width="50%" valign="top">
 

auth/credential_store.py

@@ -151,9 +151,21 @@ def store_credential(self, user_email: str, credentials: Credentials) -> bool:
         """Store credentials to local JSON file."""
         creds_path = self._get_credential_path(user_email)
 
+        # Preserve existing refresh token if new credentials don't have one
+        # This prevents losing refresh tokens during re-authorization flows
+        refresh_token_to_store = credentials.refresh_token
+        if not refresh_token_to_store:
+            try:
+                existing_creds = self.get_credential(user_email)
+                if existing_creds and existing_creds.refresh_token:
+                    refresh_token_to_store = existing_creds.refresh_token
+                    logger.info(f"Preserved existing refresh token for {user_email} in credential store")
+            except Exception as e:
+                logger.debug(f"Could not check existing credentials to preserve refresh token: {e}")
+
         creds_data = {
             "token": credentials.token,
-            "refresh_token": credentials.refresh_token,
+            "refresh_token": refresh_token_to_store,
             "token_uri": credentials.token_uri,
             "client_id": credentials.client_id,
             "client_secret": credentials.client_secret,

auth/google_auth.py

@@ -353,7 +353,7 @@ async def start_auth_flow(
             state=oauth_state,
         )
 
-        auth_url, _ = flow.authorization_url(access_type="offline", prompt="consent")
+        auth_url, _ = flow.authorization_url(access_type="offline")
 
         session_id = None
         try:
@@ -486,16 +486,41 @@ def handle_auth_callback(
         user_google_email = user_info["email"]
         logger.info(f"Identified user_google_email: {user_google_email}")
 
-        # Save the credentials
+        # Preserve existing refresh token if new credentials don't have one
+        # Google often doesn't return refresh_token on re-authorization if one already exists
+        existing_credentials = None
         credential_store = get_credential_store()
+        try:
+            existing_credentials = credential_store.get_credential(user_google_email)
+        except Exception as e:
+            logger.debug(f"Could not load existing credentials to preserve refresh token: {e}")
+
+        # Also check OAuth21SessionStore for existing refresh token
+        store = get_oauth21_session_store()
+        existing_session_creds = store.get_credentials(user_google_email)
+
+        # Preserve refresh token from existing credentials if new one is missing
+        preserved_refresh_token = credentials.refresh_token
+        if not preserved_refresh_token:
+            if existing_credentials and existing_credentials.refresh_token:
+                preserved_refresh_token = existing_credentials.refresh_token
+                logger.info(f"Preserved existing refresh token from credential store for {user_google_email}")
+            elif existing_session_creds and existing_session_creds.refresh_token:
+                preserved_refresh_token = existing_session_creds.refresh_token
+                logger.info(f"Preserved existing refresh token from session store for {user_google_email}")
+
+        # Update credentials object with preserved refresh token if we found one
+        if preserved_refresh_token and not credentials.refresh_token:
+            credentials.refresh_token = preserved_refresh_token
+
+        # Save the credentials
         credential_store.store_credential(user_google_email, credentials)
 
         # Always save to OAuth21SessionStore for centralized management
-        store = get_oauth21_session_store()
         store.store_session(
             user_email=user_google_email,
             access_token=credentials.token,
-            refresh_token=credentials.refresh_token,
+            refresh_token=preserved_refresh_token or credentials.refresh_token,
             token_uri=credentials.token_uri,
             client_id=credentials.client_id,
             client_secret=credentials.client_secret,
@@ -505,9 +530,8 @@ def handle_auth_callback(
             issuer="https://accounts.google.com"  # Add issuer for Google tokens
         )
 
-        # If session_id is provided, also save to session cache for compatibility
-        if session_id:
-            save_credentials_to_session(session_id, credentials)
+        # Note: No need to call save_credentials_to_session() here as we've already
+        # saved to the OAuth21SessionStore above with the correct issuer and mcp_session_id
 
         return user_google_email, credentials
 
@@ -570,6 +594,9 @@ def get_credentials(
                                 user_email=user_email,
                                 access_token=credentials.token,
                                 refresh_token=credentials.refresh_token,
+                                token_uri=credentials.token_uri,
+                                client_id=credentials.client_id,
+                                client_secret=credentials.client_secret,
                                 scopes=credentials.scopes,
                                 expiry=credentials.expiry,
                                 mcp_session_id=session_id

auth/oauth21_session_store.py

@@ -311,10 +311,19 @@ def store_session(
             issuer: Token issuer (e.g., "https://accounts.google.com")
         """
         with self._lock:
+            # Preserve existing refresh token if new one is not provided
+            # This prevents losing refresh tokens during re-authorization flows
+            preserved_refresh_token = refresh_token
+            if not preserved_refresh_token:
+                existing_session = self._sessions.get(user_email)
+                if existing_session and existing_session.get("refresh_token"):
+                    preserved_refresh_token = existing_session["refresh_token"]
+                    logger.info(f"Preserved existing refresh token for {user_email} in session store")
+
             normalized_expiry = _normalize_expiry_to_naive_utc(expiry)
             session_info = {
                 "access_token": access_token,
-                "refresh_token": refresh_token,
+                "refresh_token": preserved_refresh_token,
                 "token_uri": token_uri,
                 "client_id": client_id,
                 "client_secret": client_secret,

core/tool_tiers.yaml

@@ -7,14 +7,18 @@ gmail:
 
   extended:
     - get_gmail_thread_content
+    - get_gmail_thread_metadata
     - modify_gmail_message_labels
+    - modify_gmail_thread_labels
     - list_gmail_labels
     - manage_gmail_label
     - draft_gmail_message
 
   complete:
     - get_gmail_threads_content_batch
+    - get_gmail_threads_metadata_batch
     - batch_modify_gmail_message_labels
+    - batch_modify_gmail_thread_labels
     - start_google_auth
 
 drive: