gmail: improve filter error logging and add limit check

apps/web/utils/email/google.ts

@@ -858,7 +858,11 @@ export class GmailProvider implements EmailProvider {
     addLabelIds?: string[];
     removeLabelIds?: string[];
   }) {
-    return createFilter({ gmail: this.client, ...options });
+    return createFilter({
+      gmail: this.client,
+      ...options,
+      logger: this.logger,
+    });
   }
 
   async createAutoArchiveFilter(options: {
@@ -869,6 +873,7 @@ export class GmailProvider implements EmailProvider {
       gmail: this.client,
       from: options.from,
       gmailLabelId: options.gmailLabelId,
+      logger: this.logger,
     });
   }
 

apps/web/utils/gmail/filter.ts

@@ -1,14 +1,17 @@
 import type { gmail_v1 } from "@googleapis/gmail";
 import { GmailLabel } from "@/utils/gmail/label";
 import { extractErrorInfo, withGmailRetry } from "@/utils/gmail/retry";
+import { SafeError } from "@/utils/error";
+import type { Logger } from "@/utils/logger";
 
 export async function createFilter(options: {
   gmail: gmail_v1.Gmail;
   from: string;
   addLabelIds?: string[];
   removeLabelIds?: string[];
+  logger: Logger;
 }) {
-  const { gmail, from, addLabelIds, removeLabelIds } = options;
+  const { gmail, from, addLabelIds, removeLabelIds, logger } = options;
 
   try {
     return await withGmailRetry(() =>
@@ -25,6 +28,38 @@ export async function createFilter(options: {
     );
   } catch (error) {
     if (isFilterExistsError(error)) return { status: 200 };
+
+    const errorInfo = extractErrorInfo(error);
+
+    logger.error("Failed to create Gmail filter", {
+      from,
+      addLabelIds,
+      removeLabelIds,
+      error,
+    });
+
+    // Check if it might be a filter limit issue
+    // Documentation says 400/403, but we've seen 500 in production
+    if (
+      errorInfo.status === 500 ||
+      errorInfo.status === 403 ||
+      errorInfo.status === 400
+    ) {
+      try {
+        const filters = await getFiltersList({ gmail });
+        const filterCount = filters.data?.filter?.length ?? 0;
+        if (filterCount >= 990) {
+          throw new SafeError(
+            `Gmail filter limit reached (${filterCount}/1000 filters). Please delete some existing filters in Gmail settings.`,
+          );
+        }
+      } catch (limitCheckError) {
+        if (limitCheckError instanceof SafeError) throw limitCheckError;
+        // If limit check fails, just log and continue with original error
+        logger.warn("Failed to check filter count", { error: limitCheckError });
+      }
+    }
+
     throw error;
   }
 }
@@ -33,17 +68,20 @@ export async function createAutoArchiveFilter({
   gmail,
   from,
   gmailLabelId,
+  logger,
 }: {
   gmail: gmail_v1.Gmail;
   from: string;
   gmailLabelId?: string;
+  logger: Logger;
 }) {
   try {
     return await createFilter({
       gmail,
       from,
       removeLabelIds: [GmailLabel.INBOX],
       addLabelIds: gmailLabelId ? [gmailLabelId] : undefined,
+      logger,
     });
   } catch (error) {
     if (isFilterExistsError(error)) return { status: 200 };