diff --git a/apps/sim/app/api/tools/drive/files/route.ts b/apps/sim/app/api/tools/drive/files/route.ts
index 33ecb6f10..fa4bb1596 100644
--- a/apps/sim/app/api/tools/drive/files/route.ts
+++ b/apps/sim/app/api/tools/drive/files/route.ts
@@ -1,6 +1,7 @@
 import { type NextRequest, NextResponse } from 'next/server'
 import { getSession } from '@/lib/auth'
 import { authorizeCredentialUse } from '@/lib/auth/credential-access'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
@@ -108,6 +109,14 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Failed to obtain valid access token' }, { status: 401 })
     }
 
+    if (folderId) {
+      const folderIdValidation = validateAlphanumericId(folderId, 'folderId', 50)
+      if (!folderIdValidation.isValid) {
+        logger.warn(`[${requestId}] Invalid folderId`, { error: folderIdValidation.error })
+        return NextResponse.json({ error: folderIdValidation.error }, { status: 400 })
+      }
+    }
+
     const qParts: string[] = ['trashed = false']
     if (folderId) {
       qParts.push(`'${escapeForDriveQuery(folderId)}' in parents`)
diff --git a/apps/sim/app/api/tools/gmail/add-label/route.ts b/apps/sim/app/api/tools/gmail/add-label/route.ts
index d4ddcdefb..a8f139180 100644
--- a/apps/sim/app/api/tools/gmail/add-label/route.ts
+++ b/apps/sim/app/api/tools/gmail/add-label/route.ts
@@ -1,6 +1,7 @@
 import { type NextRequest, NextResponse } from 'next/server'
 import { z } from 'zod'
 import { checkHybridAuth } from '@/lib/auth/hybrid'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 
@@ -50,6 +51,29 @@ export async function POST(request: NextRequest) {
       .map((id) => id.trim())
       .filter((id) => id.length > 0)
 
+    for (const labelId of labelIds) {
+      const labelIdValidation = validateAlphanumericId(labelId, 'labelId', 255)
+      if (!labelIdValidation.isValid) {
+        logger.warn(`[${requestId}] Invalid label ID: ${labelIdValidation.error}`)
+        return NextResponse.json(
+          {
+            success: false,
+            error: labelIdValidation.error,
+          },
+          { status: 400 }
+        )
+      }
+    }
+
+    const messageIdValidation = validateAlphanumericId(validatedData.messageId, 'messageId', 255)
+    if (!messageIdValidation.isValid) {
+      logger.warn(`[${requestId}] Invalid message ID: ${messageIdValidation.error}`)
+      return NextResponse.json(
+        { success: false, error: messageIdValidation.error },
+        { status: 400 }
+      )
+    }
+
     const gmailResponse = await fetch(
       `${GMAIL_API_BASE}/messages/${validatedData.messageId}/modify`,
       {
diff --git a/apps/sim/app/api/tools/gmail/labels/route.ts b/apps/sim/app/api/tools/gmail/labels/route.ts
index e4c8aab4b..945db0afa 100644
--- a/apps/sim/app/api/tools/gmail/labels/route.ts
+++ b/apps/sim/app/api/tools/gmail/labels/route.ts
@@ -3,6 +3,7 @@ import { account } from '@sim/db/schema'
 import { and, eq } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
 import { getSession } from '@/lib/auth'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
@@ -38,6 +39,12 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Credential ID is required' }, { status: 400 })
     }
 
+    const credentialIdValidation = validateAlphanumericId(credentialId, 'credentialId', 255)
+    if (!credentialIdValidation.isValid) {
+      logger.warn(`[${requestId}] Invalid credential ID: ${credentialIdValidation.error}`)
+      return NextResponse.json({ error: credentialIdValidation.error }, { status: 400 })
+    }
+
     let credentials = await db
       .select()
       .from(account)
diff --git a/apps/sim/app/api/tools/gmail/remove-label/route.ts b/apps/sim/app/api/tools/gmail/remove-label/route.ts
index 928d44c36..74e179c91 100644
--- a/apps/sim/app/api/tools/gmail/remove-label/route.ts
+++ b/apps/sim/app/api/tools/gmail/remove-label/route.ts
@@ -1,6 +1,7 @@
 import { type NextRequest, NextResponse } from 'next/server'
 import { z } from 'zod'
 import { checkHybridAuth } from '@/lib/auth/hybrid'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 
@@ -53,6 +54,29 @@ export async function POST(request: NextRequest) {
       .map((id) => id.trim())
       .filter((id) => id.length > 0)
 
+    for (const labelId of labelIds) {
+      const labelIdValidation = validateAlphanumericId(labelId, 'labelId', 255)
+      if (!labelIdValidation.isValid) {
+        logger.warn(`[${requestId}] Invalid label ID: ${labelIdValidation.error}`)
+        return NextResponse.json(
+          {
+            success: false,
+            error: labelIdValidation.error,
+          },
+          { status: 400 }
+        )
+      }
+    }
+
+    const messageIdValidation = validateAlphanumericId(validatedData.messageId, 'messageId', 255)
+    if (!messageIdValidation.isValid) {
+      logger.warn(`[${requestId}] Invalid message ID: ${messageIdValidation.error}`)
+      return NextResponse.json(
+        { success: false, error: messageIdValidation.error },
+        { status: 400 }
+      )
+    }
+
     const gmailResponse = await fetch(
       `${GMAIL_API_BASE}/messages/${validatedData.messageId}/modify`,
       {
diff --git a/apps/sim/app/api/tools/google_calendar/calendars/route.ts b/apps/sim/app/api/tools/google_calendar/calendars/route.ts
index 2e92521db..7fc17db6e 100644
--- a/apps/sim/app/api/tools/google_calendar/calendars/route.ts
+++ b/apps/sim/app/api/tools/google_calendar/calendars/route.ts
@@ -1,5 +1,6 @@
 import { type NextRequest, NextResponse } from 'next/server'
 import { authorizeCredentialUse } from '@/lib/auth/credential-access'
+import { validateUUID } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
@@ -25,7 +26,6 @@ export async function GET(request: NextRequest) {
   logger.info(`[${requestId}] Google Calendar calendars request received`)
 
   try {
-    // Get the credential ID from the query params
     const { searchParams } = new URL(request.url)
     const credentialId = searchParams.get('credentialId')
     const workflowId = searchParams.get('workflowId') || undefined
@@ -34,12 +34,25 @@ export async function GET(request: NextRequest) {
       logger.warn(`[${requestId}] Missing credentialId parameter`)
       return NextResponse.json({ error: 'Credential ID is required' }, { status: 400 })
     }
+
+    const credentialValidation = validateUUID(credentialId, 'credentialId')
+    if (!credentialValidation.isValid) {
+      logger.warn(`[${requestId}] Invalid credentialId format`, { credentialId })
+      return NextResponse.json({ error: credentialValidation.error }, { status: 400 })
+    }
+
+    if (workflowId) {
+      const workflowValidation = validateUUID(workflowId, 'workflowId')
+      if (!workflowValidation.isValid) {
+        logger.warn(`[${requestId}] Invalid workflowId format`, { workflowId })
+        return NextResponse.json({ error: workflowValidation.error }, { status: 400 })
+      }
+    }
     const authz = await authorizeCredentialUse(request, { credentialId, workflowId })
     if (!authz.ok || !authz.credentialOwnerUserId) {
       return NextResponse.json({ error: authz.error || 'Unauthorized' }, { status: 403 })
     }
 
-    // Refresh access token if needed using the utility function
     const accessToken = await refreshAccessTokenIfNeeded(
       credentialId,
       authz.credentialOwnerUserId,
@@ -50,7 +63,6 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Failed to obtain valid access token' }, { status: 401 })
     }
 
-    // Fetch calendars from Google Calendar API
     logger.info(`[${requestId}] Fetching calendars from Google Calendar API`)
     const calendarResponse = await fetch(
       'https://www.googleapis.com/calendar/v3/users/me/calendarList',
@@ -81,7 +93,6 @@ export async function GET(request: NextRequest) {
     const data = await calendarResponse.json()
     const calendars: CalendarListItem[] = data.items || []
 
-    // Sort calendars with primary first, then alphabetically
     calendars.sort((a, b) => {
       if (a.primary && !b.primary) return -1
       if (!a.primary && b.primary) return 1
diff --git a/apps/sim/app/api/tools/microsoft-teams/channels/route.ts b/apps/sim/app/api/tools/microsoft-teams/channels/route.ts
index 990819bc7..0d07ca433 100644
--- a/apps/sim/app/api/tools/microsoft-teams/channels/route.ts
+++ b/apps/sim/app/api/tools/microsoft-teams/channels/route.ts
@@ -1,5 +1,6 @@
 import { NextResponse } from 'next/server'
 import { authorizeCredentialUse } from '@/lib/auth/credential-access'
+import { validateMicrosoftGraphId } from '@/lib/core/security/input-validation'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
 
@@ -23,6 +24,12 @@ export async function POST(request: Request) {
       return NextResponse.json({ error: 'Team ID is required' }, { status: 400 })
     }
 
+    const teamIdValidation = validateMicrosoftGraphId(teamId, 'Team ID')
+    if (!teamIdValidation.isValid) {
+      logger.warn('Invalid team ID provided', { teamId, error: teamIdValidation.error })
+      return NextResponse.json({ error: teamIdValidation.error }, { status: 400 })
+    }
+
     try {
       const authz = await authorizeCredentialUse(request as any, {
         credentialId: credential,
@@ -70,7 +77,6 @@ export async function POST(request: Request) {
           endpoint: `https://graph.microsoft.com/v1.0/teams/${teamId}/channels`,
         })
 
-        // Check for auth errors specifically
         if (response.status === 401) {
           return NextResponse.json(
             {
@@ -93,7 +99,6 @@ export async function POST(request: Request) {
     } catch (innerError) {
       logger.error('Error during API requests:', innerError)
 
-      // Check if it's an authentication error
       const errorMessage = innerError instanceof Error ? innerError.message : String(innerError)
       if (
         errorMessage.includes('auth') ||
diff --git a/apps/sim/app/api/tools/microsoft-teams/chats/route.ts b/apps/sim/app/api/tools/microsoft-teams/chats/route.ts
index 439db3454..356f92475 100644
--- a/apps/sim/app/api/tools/microsoft-teams/chats/route.ts
+++ b/apps/sim/app/api/tools/microsoft-teams/chats/route.ts
@@ -1,5 +1,6 @@
 import { NextResponse } from 'next/server'
 import { authorizeCredentialUse } from '@/lib/auth/credential-access'
+import { validateMicrosoftGraphId } from '@/lib/core/security/input-validation'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
 
@@ -7,21 +8,35 @@ export const dynamic = 'force-dynamic'
 
 const logger = createLogger('TeamsChatsAPI')
 
-// Helper function to get chat members and create a meaningful name
+/**
+ * Helper function to get chat members and create a meaningful name
+ *
+ * @param chatId - Microsoft Teams chat ID to get display name for
+ * @param accessToken - Access token for Microsoft Graph API
+ * @param chatTopic - Optional existing chat topic
+ * @returns A meaningful display name for the chat
+ */
 const getChatDisplayName = async (
   chatId: string,
   accessToken: string,
   chatTopic?: string
 ): Promise<string> => {
   try {
-    // If the chat already has a topic, use it
+    const chatIdValidation = validateMicrosoftGraphId(chatId, 'chatId')
+    if (!chatIdValidation.isValid) {
+      logger.warn('Invalid chat ID in getChatDisplayName', {
+        error: chatIdValidation.error,
+        chatId: chatId.substring(0, 50),
+      })
+      return `Chat ${chatId.substring(0, 8)}...`
+    }
+
     if (chatTopic?.trim() && chatTopic !== 'null') {
       return chatTopic
     }
 
-    // Fetch chat members to create a meaningful name
     const membersResponse = await fetch(
-      `https://graph.microsoft.com/v1.0/chats/${chatId}/members`,
+      `https://graph.microsoft.com/v1.0/chats/${encodeURIComponent(chatId)}/members`,
       {
         method: 'GET',
         headers: {
@@ -35,27 +50,25 @@ const getChatDisplayName = async (
       const membersData = await membersResponse.json()
       const members = membersData.value || []
 
-      // Filter out the current user and get display names
       const memberNames = members
         .filter((member: any) => member.displayName && member.displayName !== 'Unknown')
         .map((member: any) => member.displayName)
-        .slice(0, 3) // Limit to first 3 names to avoid very long names
+        .slice(0, 3)
 
       if (memberNames.length > 0) {
         if (memberNames.length === 1) {
-          return memberNames[0] // 1:1 chat
+          return memberNames[0]
         }
         if (memberNames.length === 2) {
-          return memberNames.join(' & ') // 2-person group
+          return memberNames.join(' & ')
         }
-        return `${memberNames.slice(0, 2).join(', ')} & ${memberNames.length - 2} more` // Larger group
+        return `${memberNames.slice(0, 2).join(', ')} & ${memberNames.length - 2} more`
       }
     }
 
-    // Fallback: try to get a better name from recent messages
     try {
       const messagesResponse = await fetch(
-        `https://graph.microsoft.com/v1.0/chats/${chatId}/messages?$top=10&$orderby=createdDateTime desc`,
+        `https://graph.microsoft.com/v1.0/chats/${encodeURIComponent(chatId)}/messages?$top=10&$orderby=createdDateTime desc`,
         {
           method: 'GET',
           headers: {
@@ -69,14 +82,12 @@ const getChatDisplayName = async (
         const messagesData = await messagesResponse.json()
         const messages = messagesData.value || []
 
-        // Look for chat rename events
         for (const message of messages) {
           if (message.eventDetail?.chatDisplayName) {
             return message.eventDetail.chatDisplayName
           }
         }
 
-        // Get unique sender names from recent messages as last resort
         const senderNames = [
           ...new Set(
             messages
@@ -103,7 +114,6 @@ const getChatDisplayName = async (
       )
     }
 
-    // Final fallback
     return `Chat ${chatId.split(':')[0] || chatId.substring(0, 8)}...`
   } catch (error) {
     logger.warn(
@@ -146,7 +156,6 @@ export async function POST(request: Request) {
         return NextResponse.json({ error: 'Could not retrieve access token' }, { status: 401 })
       }
 
-      // Now try to fetch the chats
       const response = await fetch('https://graph.microsoft.com/v1.0/me/chats', {
         method: 'GET',
         headers: {
@@ -163,7 +172,6 @@ export async function POST(request: Request) {
           endpoint: 'https://graph.microsoft.com/v1.0/me/chats',
         })
 
-        // Check for auth errors specifically
         if (response.status === 401) {
           return NextResponse.json(
             {
@@ -179,7 +187,6 @@ export async function POST(request: Request) {
 
       const data = await response.json()
 
-      // Process chats with enhanced display names
       const chats = await Promise.all(
         data.value.map(async (chat: any) => ({
           id: chat.id,
@@ -193,7 +200,6 @@ export async function POST(request: Request) {
     } catch (innerError) {
       logger.error('Error during API requests:', innerError)
 
-      // Check if it's an authentication error
       const errorMessage = innerError instanceof Error ? innerError.message : String(innerError)
       if (
         errorMessage.includes('auth') ||
diff --git a/apps/sim/app/api/tools/onedrive/files/route.ts b/apps/sim/app/api/tools/onedrive/files/route.ts
index 0d916410f..0a551f5bd 100644
--- a/apps/sim/app/api/tools/onedrive/files/route.ts
+++ b/apps/sim/app/api/tools/onedrive/files/route.ts
@@ -4,6 +4,7 @@ import { account } from '@sim/db/schema'
 import { eq } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
 import { getSession } from '@/lib/auth'
+import { validateMicrosoftGraphId } from '@/lib/core/security/input-validation'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
 
@@ -36,6 +37,12 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Credential ID is required' }, { status: 400 })
     }
 
+    const credentialIdValidation = validateMicrosoftGraphId(credentialId, 'credentialId')
+    if (!credentialIdValidation.isValid) {
+      logger.warn(`[${requestId}] Invalid credential ID`, { error: credentialIdValidation.error })
+      return NextResponse.json({ error: credentialIdValidation.error }, { status: 400 })
+    }
+
     logger.info(`[${requestId}] Fetching credential`, { credentialId })
 
     const credentials = await db.select().from(account).where(eq(account.id, credentialId)).limit(1)
diff --git a/apps/sim/app/api/tools/onedrive/folders/route.ts b/apps/sim/app/api/tools/onedrive/folders/route.ts
index b62d41179..61adffde4 100644
--- a/apps/sim/app/api/tools/onedrive/folders/route.ts
+++ b/apps/sim/app/api/tools/onedrive/folders/route.ts
@@ -4,6 +4,7 @@ import { account } from '@sim/db/schema'
 import { eq } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
 import { getSession } from '@/lib/auth'
+import { validateMicrosoftGraphId } from '@/lib/core/security/input-validation'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
 
@@ -33,6 +34,12 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Credential ID is required' }, { status: 400 })
     }
 
+    const credentialIdValidation = validateMicrosoftGraphId(credentialId, 'credentialId')
+    if (!credentialIdValidation.isValid) {
+      logger.warn(`[${requestId}] Invalid credential ID`, { error: credentialIdValidation.error })
+      return NextResponse.json({ error: credentialIdValidation.error }, { status: 400 })
+    }
+
     const credentials = await db.select().from(account).where(eq(account.id, credentialId)).limit(1)
     if (!credentials.length) {
       return NextResponse.json({ error: 'Credential not found' }, { status: 404 })
@@ -48,7 +55,6 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Failed to obtain valid access token' }, { status: 401 })
     }
 
-    // Build URL for OneDrive folders
     let url = `https://graph.microsoft.com/v1.0/me/drive/root/children?$filter=folder ne null&$select=id,name,folder,webUrl,createdDateTime,lastModifiedDateTime&$top=50`
 
     if (query) {
@@ -71,7 +77,7 @@ export async function GET(request: NextRequest) {
 
     const data = await response.json()
     const folders = (data.value || [])
-      .filter((item: MicrosoftGraphDriveItem) => item.folder) // Only folders
+      .filter((item: MicrosoftGraphDriveItem) => item.folder)
       .map((folder: MicrosoftGraphDriveItem) => ({
         id: folder.id,
         name: folder.name,
diff --git a/apps/sim/app/api/tools/onedrive/upload/route.ts b/apps/sim/app/api/tools/onedrive/upload/route.ts
index db7936120..c5c4d29ae 100644
--- a/apps/sim/app/api/tools/onedrive/upload/route.ts
+++ b/apps/sim/app/api/tools/onedrive/upload/route.ts
@@ -2,6 +2,7 @@ import { type NextRequest, NextResponse } from 'next/server'
 import * as XLSX from 'xlsx'
 import { z } from 'zod'
 import { checkHybridAuth } from '@/lib/auth/hybrid'
+import { validateMicrosoftGraphId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import {
@@ -28,9 +29,9 @@ const ExcelValuesSchema = z.union([
 const OneDriveUploadSchema = z.object({
   accessToken: z.string().min(1, 'Access token is required'),
   fileName: z.string().min(1, 'File name is required'),
-  file: z.any().optional(), // UserFile object (optional for blank Excel creation)
+  file: z.any().optional(),
   folderId: z.string().optional().nullable(),
-  mimeType: z.string().nullish(), // Accept string, null, or undefined
+  mimeType: z.string().nullish(),
   values: ExcelValuesSchema.optional().nullable(),
 })
 
@@ -62,24 +63,19 @@ export async function POST(request: NextRequest) {
     let fileBuffer: Buffer
     let mimeType: string
 
-    // Check if we're creating a blank Excel file
     const isExcelCreation =
       validatedData.mimeType ===
         'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' && !validatedData.file
 
     if (isExcelCreation) {
-      // Create a blank Excel workbook
-
       const workbook = XLSX.utils.book_new()
       const worksheet = XLSX.utils.aoa_to_sheet([[]])
       XLSX.utils.book_append_sheet(workbook, worksheet, 'Sheet1')
 
-      // Generate XLSX file as buffer
       const xlsxBuffer = XLSX.write(workbook, { type: 'buffer', bookType: 'xlsx' })
       fileBuffer = Buffer.from(xlsxBuffer)
       mimeType = 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
     } else {
-      // Handle regular file upload
       const rawFile = validatedData.file
 
       if (!rawFile) {
@@ -108,7 +104,6 @@ export async function POST(request: NextRequest) {
         fileToProcess = rawFile
       }
 
-      // Convert to UserFile format
       let userFile
       try {
         userFile = processSingleFileToUserFile(fileToProcess, requestId, logger)
@@ -138,7 +133,7 @@ export async function POST(request: NextRequest) {
       mimeType = userFile.type || 'application/octet-stream'
     }
 
-    const maxSize = 250 * 1024 * 1024 // 250MB
+    const maxSize = 250 * 1024 * 1024
     if (fileBuffer.length > maxSize) {
       const sizeMB = (fileBuffer.length / (1024 * 1024)).toFixed(2)
       logger.warn(`[${requestId}] File too large: ${sizeMB}MB`)
@@ -151,7 +146,6 @@ export async function POST(request: NextRequest) {
       )
     }
 
-    // Ensure file name has an appropriate extension
     let fileName = validatedData.fileName
     const hasExtension = fileName.includes('.') && fileName.lastIndexOf('.') > 0
 
@@ -169,6 +163,17 @@ export async function POST(request: NextRequest) {
     const folderId = validatedData.folderId?.trim()
 
     if (folderId && folderId !== '') {
+      const folderIdValidation = validateMicrosoftGraphId(folderId, 'folderId')
+      if (!folderIdValidation.isValid) {
+        logger.warn(`[${requestId}] Invalid folder ID`, { error: folderIdValidation.error })
+        return NextResponse.json(
+          {
+            success: false,
+            error: folderIdValidation.error,
+          },
+          { status: 400 }
+        )
+      }
       uploadUrl = `${MICROSOFT_GRAPH_BASE}/me/drive/items/${encodeURIComponent(folderId)}:/${encodeURIComponent(fileName)}:/content`
     } else {
       uploadUrl = `${MICROSOFT_GRAPH_BASE}/me/drive/root:/${encodeURIComponent(fileName)}:/content`
@@ -197,14 +202,12 @@ export async function POST(request: NextRequest) {
 
     const fileData = await uploadResponse.json()
 
-    // If this is an Excel creation and values were provided, write them using the Excel API
     let excelWriteResult: any | undefined
     const shouldWriteExcelContent =
       isExcelCreation && Array.isArray(excelValues) && excelValues.length > 0
 
     if (shouldWriteExcelContent) {
       try {
-        // Create a workbook session to ensure reliability and persistence of changes
         let workbookSessionId: string | undefined
         const sessionResp = await fetch(
           `${MICROSOFT_GRAPH_BASE}/me/drive/items/${encodeURIComponent(fileData.id)}/workbook/createSession`,
@@ -223,7 +226,6 @@ export async function POST(request: NextRequest) {
           workbookSessionId = sessionData?.id
         }
 
-        // Determine the first worksheet name
         let sheetName = 'Sheet1'
         try {
           const listUrl = `${MICROSOFT_GRAPH_BASE}/me/drive/items/${encodeURIComponent(
@@ -272,7 +274,6 @@ export async function POST(request: NextRequest) {
           return paddedRow
         })
 
-        // Compute concise end range from A1 and matrix size (no network round-trip)
         const indexToColLetters = (index: number): string => {
           let n = index
           let s = ''
@@ -313,7 +314,6 @@ export async function POST(request: NextRequest) {
             statusText: excelWriteResponse?.statusText,
             error: errorText,
           })
-          // Do not fail the entire request; return upload success with write error details
           excelWriteResult = {
             success: false,
             error: `Excel write failed: ${excelWriteResponse?.statusText || 'unknown'}`,
@@ -321,7 +321,6 @@ export async function POST(request: NextRequest) {
           }
         } else {
           const writeData = await excelWriteResponse.json()
-          // The Range PATCH returns a Range object; log address and values length
           const addr = writeData.address || writeData.addressLocal
           const v = writeData.values || []
           excelWriteResult = {
@@ -333,7 +332,6 @@ export async function POST(request: NextRequest) {
           }
         }
 
-        // Attempt to close the workbook session if one was created
         if (workbookSessionId) {
           try {
             const closeResp = await fetch(
diff --git a/apps/sim/app/api/tools/outlook/folders/route.ts b/apps/sim/app/api/tools/outlook/folders/route.ts
index 90e4de55e..91395e684 100644
--- a/apps/sim/app/api/tools/outlook/folders/route.ts
+++ b/apps/sim/app/api/tools/outlook/folders/route.ts
@@ -3,6 +3,7 @@ import { account } from '@sim/db/schema'
 import { eq } from 'drizzle-orm'
 import { NextResponse } from 'next/server'
 import { getSession } from '@/lib/auth'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
@@ -29,8 +30,13 @@ export async function GET(request: Request) {
       return NextResponse.json({ error: 'Credential ID is required' }, { status: 400 })
     }
 
+    const credentialIdValidation = validateAlphanumericId(credentialId, 'credentialId')
+    if (!credentialIdValidation.isValid) {
+      logger.warn('Invalid credentialId format', { error: credentialIdValidation.error })
+      return NextResponse.json({ error: credentialIdValidation.error }, { status: 400 })
+    }
+
     try {
-      // Ensure we have a session for permission checks
       const sessionUserId = session?.user?.id || ''
 
       if (!sessionUserId) {
@@ -38,7 +44,6 @@ export async function GET(request: Request) {
         return NextResponse.json({ error: 'Authentication required' }, { status: 401 })
       }
 
-      // Resolve the credential owner to support collaborator-owned credentials
       const creds = await db.select().from(account).where(eq(account.id, credentialId)).limit(1)
       if (!creds.length) {
         logger.warn('Credential not found', { credentialId })
@@ -79,7 +84,6 @@ export async function GET(request: Request) {
           endpoint: 'https://graph.microsoft.com/v1.0/me/mailFolders',
         })
 
-        // Check for auth errors specifically
         if (response.status === 401) {
           return NextResponse.json(
             {
@@ -96,7 +100,6 @@ export async function GET(request: Request) {
       const data = await response.json()
       const folders = data.value || []
 
-      // Transform folders to match the expected format
       const transformedFolders = folders.map((folder: OutlookFolder) => ({
         id: folder.id,
         name: folder.displayName,
@@ -111,7 +114,6 @@ export async function GET(request: Request) {
     } catch (innerError) {
       logger.error('Error during API requests:', innerError)
 
-      // Check if it's an authentication error
       const errorMessage = innerError instanceof Error ? innerError.message : String(innerError)
       if (
         errorMessage.includes('auth') ||
diff --git a/apps/sim/app/api/tools/sharepoint/sites/route.ts b/apps/sim/app/api/tools/sharepoint/sites/route.ts
index 3448ff22e..2f39cc049 100644
--- a/apps/sim/app/api/tools/sharepoint/sites/route.ts
+++ b/apps/sim/app/api/tools/sharepoint/sites/route.ts
@@ -4,6 +4,7 @@ import { account } from '@sim/db/schema'
 import { eq } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
 import { getSession } from '@/lib/auth'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
 import type { SharepointSite } from '@/tools/sharepoint/types'
@@ -32,6 +33,12 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Credential ID is required' }, { status: 400 })
     }
 
+    const credentialIdValidation = validateAlphanumericId(credentialId, 'credentialId', 255)
+    if (!credentialIdValidation.isValid) {
+      logger.warn(`[${requestId}] Invalid credential ID`, { error: credentialIdValidation.error })
+      return NextResponse.json({ error: credentialIdValidation.error }, { status: 400 })
+    }
+
     const credentials = await db.select().from(account).where(eq(account.id, credentialId)).limit(1)
     if (!credentials.length) {
       return NextResponse.json({ error: 'Credential not found' }, { status: 404 })
@@ -47,8 +54,6 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Failed to obtain valid access token' }, { status: 401 })
     }
 
-    // Build URL for SharePoint sites
-    // Use search=* to get all sites the user has access to, or search for specific query
     const searchQuery = query || '*'
     const url = `https://graph.microsoft.com/v1.0/sites?search=${encodeURIComponent(searchQuery)}&$select=id,name,displayName,webUrl,createdDateTime,lastModifiedDateTime&$top=50`
 
diff --git a/apps/sim/app/api/tools/slack/channels/route.ts b/apps/sim/app/api/tools/slack/channels/route.ts
index be572492b..d48d06613 100644
--- a/apps/sim/app/api/tools/slack/channels/route.ts
+++ b/apps/sim/app/api/tools/slack/channels/route.ts
@@ -1,5 +1,6 @@
 import { NextResponse } from 'next/server'
 import { authorizeCredentialUse } from '@/lib/auth/credential-access'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
@@ -93,7 +94,6 @@ export async function POST(request: Request) {
       }
     }
 
-    // Filter to channels the bot can access and format the response
     const channels = (data.channels || [])
       .filter((channel: SlackChannel) => {
         const canAccess = !channel.is_archived && (channel.is_member || !channel.is_private)
@@ -106,6 +106,28 @@ export async function POST(request: Request) {
 
         return canAccess
       })
+      .filter((channel: SlackChannel) => {
+        const validation = validateAlphanumericId(channel.id, 'channelId', 50)
+
+        if (!validation.isValid) {
+          logger.warn('Invalid channel ID received from Slack API', {
+            channelId: channel.id,
+            channelName: channel.name,
+            error: validation.error,
+          })
+          return false
+        }
+
+        if (!/^[CDG][A-Z0-9]+$/i.test(channel.id)) {
+          logger.warn('Channel ID does not match Slack format', {
+            channelId: channel.id,
+            channelName: channel.name,
+          })
+          return false
+        }
+
+        return true
+      })
       .map((channel: SlackChannel) => ({
         id: channel.id,
         name: channel.name,
diff --git a/apps/sim/app/api/tools/slack/users/route.ts b/apps/sim/app/api/tools/slack/users/route.ts
index 97d73c88d..666800f56 100644
--- a/apps/sim/app/api/tools/slack/users/route.ts
+++ b/apps/sim/app/api/tools/slack/users/route.ts
@@ -1,5 +1,6 @@
 import { NextResponse } from 'next/server'
 import { authorizeCredentialUse } from '@/lib/auth/credential-access'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
@@ -20,13 +21,21 @@ export async function POST(request: Request) {
   try {
     const requestId = generateRequestId()
     const body = await request.json()
-    const { credential, workflowId } = body
+    const { credential, workflowId, userId } = body
 
     if (!credential) {
       logger.error('Missing credential in request')
       return NextResponse.json({ error: 'Credential is required' }, { status: 400 })
     }
 
+    if (userId !== undefined && userId !== null) {
+      const validation = validateAlphanumericId(userId, 'userId', 100)
+      if (!validation.isValid) {
+        logger.warn('Invalid Slack user ID', { userId, error: validation.error })
+        return NextResponse.json({ error: validation.error }, { status: 400 })
+      }
+    }
+
     let accessToken: string
     const isBotToken = credential.startsWith('xoxb-')
 
@@ -63,6 +72,17 @@ export async function POST(request: Request) {
       logger.info('Using OAuth token for Slack API')
     }
 
+    if (userId) {
+      const userData = await fetchSlackUser(accessToken, userId)
+      const user = {
+        id: userData.user.id,
+        name: userData.user.name,
+        real_name: userData.user.real_name || userData.user.name,
+      }
+      logger.info(`Successfully fetched Slack user: ${userId}`)
+      return NextResponse.json({ user })
+    }
+
     const data = await fetchSlackUsers(accessToken)
 
     const users = (data.members || [])
@@ -87,6 +107,31 @@ export async function POST(request: Request) {
   }
 }
 
+async function fetchSlackUser(accessToken: string, userId: string) {
+  const url = new URL('https://slack.com/api/users.info')
+  url.searchParams.append('user', userId)
+
+  const response = await fetch(url.toString(), {
+    method: 'GET',
+    headers: {
+      Authorization: `Bearer ${accessToken}`,
+      'Content-Type': 'application/json',
+    },
+  })
+
+  if (!response.ok) {
+    throw new Error(`Slack API error: ${response.status} ${response.statusText}`)
+  }
+
+  const data = await response.json()
+
+  if (!data.ok) {
+    throw new Error(data.error || 'Failed to fetch user')
+  }
+
+  return data
+}
+
 async function fetchSlackUsers(accessToken: string) {
   const url = new URL('https://slack.com/api/users.list')
   url.searchParams.append('limit', '200')
diff --git a/apps/sim/app/api/tools/wealthbox/items/route.ts b/apps/sim/app/api/tools/wealthbox/items/route.ts
index b8b7a514d..dd041f5d9 100644
--- a/apps/sim/app/api/tools/wealthbox/items/route.ts
+++ b/apps/sim/app/api/tools/wealthbox/items/route.ts
@@ -3,6 +3,7 @@ import { account } from '@sim/db/schema'
 import { eq } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
 import { getSession } from '@/lib/auth'
+import { validateEnum, validatePathSegment } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
@@ -11,7 +12,6 @@ export const dynamic = 'force-dynamic'
 
 const logger = createLogger('WealthboxItemsAPI')
 
-// Interface for transformed Wealthbox items
 interface WealthboxItem {
   id: string
   name: string
@@ -45,12 +45,23 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({ error: 'Credential ID is required' }, { status: 400 })
     }
 
-    if (type !== 'contact') {
+    const credentialIdValidation = validatePathSegment(credentialId, {
+      paramName: 'credentialId',
+      maxLength: 100,
+      allowHyphens: true,
+      allowUnderscores: true,
+      allowDots: false,
+    })
+    if (!credentialIdValidation.isValid) {
+      logger.warn(`[${requestId}] Invalid credentialId format: ${credentialId}`)
+      return NextResponse.json({ error: credentialIdValidation.error }, { status: 400 })
+    }
+
+    const ALLOWED_TYPES = ['contact'] as const
+    const typeValidation = validateEnum(type, ALLOWED_TYPES, 'type')
+    if (!typeValidation.isValid) {
       logger.warn(`[${requestId}] Invalid item type: ${type}`)
-      return NextResponse.json(
-        { error: 'Invalid item type. Only contact is supported.' },
-        { status: 400 }
-      )
+      return NextResponse.json({ error: typeValidation.error }, { status: 400 })
     }
 
     const credentials = await db.select().from(account).where(eq(account.id, credentialId)).limit(1)
diff --git a/apps/sim/app/api/tools/webflow/sites/route.ts b/apps/sim/app/api/tools/webflow/sites/route.ts
index 2cfc4698a..f5fd93ee2 100644
--- a/apps/sim/app/api/tools/webflow/sites/route.ts
+++ b/apps/sim/app/api/tools/webflow/sites/route.ts
@@ -1,5 +1,6 @@
 import { NextResponse } from 'next/server'
 import { authorizeCredentialUse } from '@/lib/auth/credential-access'
+import { validateAlphanumericId } from '@/lib/core/security/input-validation'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { createLogger } from '@/lib/logs/console/logger'
 import { refreshAccessTokenIfNeeded } from '@/app/api/auth/oauth/utils'
@@ -12,13 +13,21 @@ export async function POST(request: Request) {
   try {
     const requestId = generateRequestId()
     const body = await request.json()
-    const { credential, workflowId } = body
+    const { credential, workflowId, siteId } = body
 
     if (!credential) {
       logger.error('Missing credential in request')
       return NextResponse.json({ error: 'Credential is required' }, { status: 400 })
     }
 
+    if (siteId) {
+      const siteIdValidation = validateAlphanumericId(siteId, 'siteId')
+      if (!siteIdValidation.isValid) {
+        logger.error('Invalid siteId', { error: siteIdValidation.error })
+        return NextResponse.json({ error: siteIdValidation.error }, { status: 400 })
+      }
+    }
+
     const authz = await authorizeCredentialUse(request as any, {
       credentialId: credential,
       workflowId,
@@ -46,7 +55,11 @@ export async function POST(request: Request) {
       )
     }
 
-    const response = await fetch('https://api.webflow.com/v2/sites', {
+    const url = siteId
+      ? `https://api.webflow.com/v2/sites/${siteId}`
+      : 'https://api.webflow.com/v2/sites'
+
+    const response = await fetch(url, {
       headers: {
         Authorization: `Bearer ${accessToken}`,
         accept: 'application/json',
@@ -58,6 +71,7 @@ export async function POST(request: Request) {
       logger.error('Failed to fetch Webflow sites', {
         status: response.status,
         error: errorData,
+        siteId: siteId || 'all',
       })
       return NextResponse.json(
         { error: 'Failed to fetch Webflow sites', details: errorData },
@@ -66,7 +80,13 @@ export async function POST(request: Request) {
     }
 
     const data = await response.json()
-    const sites = data.sites || []
+
+    let sites: any[]
+    if (siteId) {
+      sites = [data]
+    } else {
+      sites = data.sites || []
+    }
 
     const formattedSites = sites.map((site: any) => ({
       id: site.id,
diff --git a/apps/sim/lib/core/security/input-validation.ts b/apps/sim/lib/core/security/input-validation.ts
index 0d0bd41a3..cf1970d33 100644
--- a/apps/sim/lib/core/security/input-validation.ts
+++ b/apps/sim/lib/core/security/input-validation.ts
@@ -958,3 +958,112 @@ export function createPinnedUrl(originalUrl: string, resolvedIP: string): string
   const port = parsed.port ? `:${parsed.port}` : ''
   return `${parsed.protocol}//${resolvedIP}${port}${parsed.pathname}${parsed.search}`
 }
+
+/**
+ * Validates a Google Calendar ID
+ *
+ * Google Calendar IDs can be:
+ * - "primary" (literal string for the user's primary calendar)
+ * - Email addresses (for user calendars)
+ * - Alphanumeric strings with hyphens, underscores, and dots (for other calendars)
+ *
+ * This validator allows these legitimate formats while blocking path traversal and injection attempts.
+ *
+ * @param value - The calendar ID to validate
+ * @param paramName - Name of the parameter for error messages
+ * @returns ValidationResult
+ *
+ * @example
+ * ```typescript
+ * const result = validateGoogleCalendarId(calendarId, 'calendarId')
+ * if (!result.isValid) {
+ *   return NextResponse.json({ error: result.error }, { status: 400 })
+ * }
+ * ```
+ */
+export function validateGoogleCalendarId(
+  value: string | null | undefined,
+  paramName = 'calendarId'
+): ValidationResult {
+  if (value === null || value === undefined || value === '') {
+    return {
+      isValid: false,
+      error: `${paramName} is required`,
+    }
+  }
+
+  if (value === 'primary') {
+    return { isValid: true, sanitized: value }
+  }
+
+  const pathTraversalPatterns = [
+    '../',
+    '..\\',
+    '%2e%2e%2f',
+    '%2e%2e/',
+    '..%2f',
+    '%2e%2e%5c',
+    '%2e%2e\\',
+    '..%5c',
+    '%252e%252e%252f',
+  ]
+
+  const lowerValue = value.toLowerCase()
+  for (const pattern of pathTraversalPatterns) {
+    if (lowerValue.includes(pattern)) {
+      logger.warn('Path traversal attempt in Google Calendar ID', {
+        paramName,
+        value: value.substring(0, 100),
+      })
+      return {
+        isValid: false,
+        error: `${paramName} contains invalid path traversal sequence`,
+      }
+    }
+  }
+
+  if (/[\x00-\x1f\x7f]/.test(value) || value.includes('%00')) {
+    logger.warn('Control characters in Google Calendar ID', { paramName })
+    return {
+      isValid: false,
+      error: `${paramName} contains invalid control characters`,
+    }
+  }
+
+  if (value.includes('\n') || value.includes('\r')) {
+    return {
+      isValid: false,
+      error: `${paramName} contains invalid newline characters`,
+    }
+  }
+
+  const emailPattern = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/
+  if (emailPattern.test(value)) {
+    return { isValid: true, sanitized: value }
+  }
+
+  const calendarIdPattern = /^[a-zA-Z0-9._@%#+-]+$/
+  if (!calendarIdPattern.test(value)) {
+    logger.warn('Invalid Google Calendar ID format', {
+      paramName,
+      value: value.substring(0, 100),
+    })
+    return {
+      isValid: false,
+      error: `${paramName} format is invalid. Must be "primary", an email address, or an alphanumeric ID`,
+    }
+  }
+
+  if (value.length > 255) {
+    logger.warn('Google Calendar ID exceeds maximum length', {
+      paramName,
+      length: value.length,
+    })
+    return {
+      isValid: false,
+      error: `${paramName} exceeds maximum length of 255 characters`,
+    }
+  }
+
+  return { isValid: true, sanitized: value }
+}