refactor(webhooks): decompose provider-subscriptions into handler registry pattern

Move all provider-specific subscription create/delete logic from the monolithic
provider-subscriptions.ts into individual provider handler files via new
createSubscription/deleteSubscription methods on WebhookProviderHandler.

Replace the two massive if-else dispatch chains (11 branches each) with simple
registry lookups via getProviderHandler(). provider-subscriptions.ts reduced
from 2,337 lines to 128 lines (orchestration only).

Also migrate polling configuration (gmail, outlook, rss, imap) into provider
handlers via configurePolling() method, and challenge/verification handling
(slack, whatsapp, teams) via handleChallenge() method. Delete polling-config.ts.

Create new handler files for fathom and lemlist providers. Extract shared
subscription utilities into subscription-utils.ts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: waleedlatif1

apps/sim/app/api/webhooks/route.ts

@@ -11,16 +11,12 @@ import { generateRequestId } from '@/lib/core/utils/request'
 import { getProviderIdFromServiceId } from '@/lib/oauth'
 import { captureServerEvent } from '@/lib/posthog/server'
 import { resolveEnvVarsInObject } from '@/lib/webhooks/env-resolver'
-import {
-  configureGmailPolling,
-  configureOutlookPolling,
-  configureRssPolling,
-} from '@/lib/webhooks/polling-config'
 import {
   cleanupExternalWebhook,
   createExternalWebhookSubscription,
   shouldRecreateExternalWebhookSubscription,
 } from '@/lib/webhooks/provider-subscriptions'
+import { getProviderHandler } from '@/lib/webhooks/providers'
 import { mergeNonUserFields } from '@/lib/webhooks/utils'
 import { syncWebhooksForCredentialSet } from '@/lib/webhooks/utils.server'
 import { authorizeWorkflowByWorkspacePermission } from '@/lib/workflows/utils'
@@ -402,24 +398,24 @@ export async function POST(request: NextRequest) {
             )
           }
 
-          const needsConfiguration = provider === 'gmail' || provider === 'outlook'
+          const providerHandler = getProviderHandler(provider)
 
-          if (needsConfiguration) {
-            const configureFunc =
-              provider === 'gmail' ? configureGmailPolling : configureOutlookPolling
+          if (providerHandler.configurePolling) {
             const configureErrors: string[] = []
 
             for (const wh of syncResult.webhooks) {
               if (wh.isNew) {
-                // Fetch the webhook data for configuration
                 const webhookRows = await db
                   .select()
                   .from(webhook)
                   .where(and(eq(webhook.id, wh.id), isNull(webhook.archivedAt)))
                   .limit(1)
 
                 if (webhookRows.length > 0) {
-                  const success = await configureFunc(webhookRows[0], requestId)
+                  const success = await providerHandler.configurePolling({
+                    webhook: webhookRows[0],
+                    requestId,
+                  })
                   if (!success) {
                     configureErrors.push(
                       `Failed to configure webhook for credential ${wh.credentialId}`
@@ -436,7 +432,6 @@ export async function POST(request: NextRequest) {
               configureErrors.length > 0 &&
               configureErrors.length === syncResult.webhooks.length
             ) {
-              // All configurations failed - roll back
               logger.error(`[${requestId}] All webhook configurations failed, rolling back`)
               for (const wh of syncResult.webhooks) {
                 await db.delete(webhook).where(eq(webhook.id, wh.id))
@@ -629,115 +624,51 @@ export async function POST(request: NextRequest) {
       }
     }
 
-    // --- Gmail/Outlook webhook setup (these don't require external subscriptions, configure after DB save) ---
-    if (savedWebhook && provider === 'gmail') {
-      logger.info(`[${requestId}] Gmail provider detected. Setting up Gmail webhook configuration.`)
-      try {
-        const success = await configureGmailPolling(savedWebhook, requestId)
-
-        if (!success) {
-          logger.error(`[${requestId}] Failed to configure Gmail polling, rolling back webhook`)
-          await revertSavedWebhook(savedWebhook, existingWebhook, requestId)
-          return NextResponse.json(
-            {
-              error: 'Failed to configure Gmail polling',
-              details: 'Please check your Gmail account permissions and try again',
-            },
-            { status: 500 }
-          )
-        }
-
-        logger.info(`[${requestId}] Successfully configured Gmail polling`)
-      } catch (err) {
-        logger.error(
-          `[${requestId}] Error setting up Gmail webhook configuration, rolling back webhook`,
-          err
-        )
-        await revertSavedWebhook(savedWebhook, existingWebhook, requestId)
-        return NextResponse.json(
-          {
-            error: 'Failed to configure Gmail webhook',
-            details: err instanceof Error ? err.message : 'Unknown error',
-          },
-          { status: 500 }
+    // --- Polling provider setup (Gmail, Outlook, RSS, IMAP, etc.) ---
+    if (savedWebhook) {
+      const pollingHandler = getProviderHandler(provider)
+      if (pollingHandler.configurePolling) {
+        logger.info(
+          `[${requestId}] ${provider} provider detected. Setting up polling configuration.`
         )
-      }
-    }
-    // --- End Gmail specific logic ---
+        try {
+          const success = await pollingHandler.configurePolling({
+            webhook: savedWebhook,
+            requestId,
+          })
 
-    // --- Outlook webhook setup ---
-    if (savedWebhook && provider === 'outlook') {
-      logger.info(
-        `[${requestId}] Outlook provider detected. Setting up Outlook webhook configuration.`
-      )
-      try {
-        const success = await configureOutlookPolling(savedWebhook, requestId)
+          if (!success) {
+            logger.error(
+              `[${requestId}] Failed to configure ${provider} polling, rolling back webhook`
+            )
+            await revertSavedWebhook(savedWebhook, existingWebhook, requestId)
+            return NextResponse.json(
+              {
+                error: `Failed to configure ${provider} polling`,
+                details: 'Please check your account permissions and try again',
+              },
+              { status: 500 }
+            )
+          }
 
-        if (!success) {
-          logger.error(`[${requestId}] Failed to configure Outlook polling, rolling back webhook`)
-          await revertSavedWebhook(savedWebhook, existingWebhook, requestId)
-          return NextResponse.json(
-            {
-              error: 'Failed to configure Outlook polling',
-              details: 'Please check your Outlook account permissions and try again',
-            },
-            { status: 500 }
+          logger.info(`[${requestId}] Successfully configured ${provider} polling`)
+        } catch (err) {
+          logger.error(
+            `[${requestId}] Error setting up ${provider} webhook configuration, rolling back webhook`,
+            err
           )
-        }
-
-        logger.info(`[${requestId}] Successfully configured Outlook polling`)
-      } catch (err) {
-        logger.error(
-          `[${requestId}] Error setting up Outlook webhook configuration, rolling back webhook`,
-          err
-        )
-        await revertSavedWebhook(savedWebhook, existingWebhook, requestId)
-        return NextResponse.json(
-          {
-            error: 'Failed to configure Outlook webhook',
-            details: err instanceof Error ? err.message : 'Unknown error',
-          },
-          { status: 500 }
-        )
-      }
-    }
-    // --- End Outlook specific logic ---
-
-    // --- RSS webhook setup ---
-    if (savedWebhook && provider === 'rss') {
-      logger.info(`[${requestId}] RSS provider detected. Setting up RSS webhook configuration.`)
-      try {
-        const success = await configureRssPolling(savedWebhook, requestId)
-
-        if (!success) {
-          logger.error(`[${requestId}] Failed to configure RSS polling, rolling back webhook`)
           await revertSavedWebhook(savedWebhook, existingWebhook, requestId)
           return NextResponse.json(
             {
-              error: 'Failed to configure RSS polling',
-              details: 'Please try again',
+              error: `Failed to configure ${provider} webhook`,
+              details: err instanceof Error ? err.message : 'Unknown error',
             },
             { status: 500 }
           )
         }
-
-        logger.info(`[${requestId}] Successfully configured RSS polling`)
-      } catch (err) {
-        logger.error(
-          `[${requestId}] Error setting up RSS webhook configuration, rolling back webhook`,
-          err
-        )
-        await revertSavedWebhook(savedWebhook, existingWebhook, requestId)
-        return NextResponse.json(
-          {
-            error: 'Failed to configure RSS webhook',
-            details: err instanceof Error ? err.message : 'Unknown error',
-          },
-          { status: 500 }
-        )
       }
     }
-    // --- End RSS specific logic ---
+    // --- End polling provider setup ---
 
     if (!targetWebhookId && savedWebhook) {
       try {

apps/sim/lib/webhooks/deploy.ts

@@ -6,12 +6,12 @@ import { nanoid } from 'nanoid'
 import type { NextRequest } from 'next/server'
 import { getProviderIdFromServiceId } from '@/lib/oauth'
 import { PendingWebhookVerificationTracker } from '@/lib/webhooks/pending-verification'
-import { configureGmailPolling, configureOutlookPolling } from '@/lib/webhooks/polling-config'
 import {
   cleanupExternalWebhook,
   createExternalWebhookSubscription,
   shouldRecreateExternalWebhookSubscription,
 } from '@/lib/webhooks/provider-subscriptions'
+import { getProviderHandler } from '@/lib/webhooks/providers'
 import { syncWebhooksForCredentialSet } from '@/lib/webhooks/utils.server'
 import { getBlock } from '@/blocks'
 import type { SubBlockConfig } from '@/blocks/types'
@@ -230,29 +230,20 @@ function buildProviderConfig(
 
 async function configurePollingIfNeeded(
   provider: string,
-  savedWebhook: any,
+  savedWebhook: Record<string, unknown>,
   requestId: string
 ): Promise<TriggerSaveError | null> {
-  if (provider === 'gmail') {
-    const success = await configureGmailPolling(savedWebhook, requestId)
-    if (!success) {
-      await db.delete(webhook).where(eq(webhook.id, savedWebhook.id))
-      return {
-        message: 'Failed to configure Gmail polling. Please check your Gmail account permissions.',
-        status: 500,
-      }
-    }
+  const handler = getProviderHandler(provider)
+  if (!handler.configurePolling) {
+    return null
   }
 
-  if (provider === 'outlook') {
-    const success = await configureOutlookPolling(savedWebhook, requestId)
-    if (!success) {
-      await db.delete(webhook).where(eq(webhook.id, savedWebhook.id))
-      return {
-        message:
-          'Failed to configure Outlook polling. Please check your Outlook account permissions.',
-        status: 500,
-      }
+  const success = await handler.configurePolling({ webhook: savedWebhook, requestId })
+  if (!success) {
+    await db.delete(webhook).where(eq(webhook.id, savedWebhook.id as string))
+    return {
+      message: `Failed to configure ${provider} polling. Please check your account permissions.`,
+      status: 500,
     }
   }
 
@@ -319,13 +310,13 @@ async function syncCredentialSetWebhooks(params: {
     }
   }
 
-  if (provider === 'gmail' || provider === 'outlook') {
-    const configureFunc = provider === 'gmail' ? configureGmailPolling : configureOutlookPolling
+  const handler = getProviderHandler(provider)
+  if (handler.configurePolling) {
     for (const wh of syncResult.webhooks) {
       if (wh.isNew) {
         const rows = await db.select().from(webhook).where(eq(webhook.id, wh.id)).limit(1)
         if (rows.length > 0) {
-          const success = await configureFunc(rows[0], requestId)
+          const success = await handler.configurePolling({ webhook: rows[0], requestId })
           if (!success) {
             await db.delete(webhook).where(eq(webhook.id, wh.id))
             return {