diff --git a/apps/web/pages/api/integrations/subscriptions/webhook.ts b/apps/web/pages/api/integrations/subscriptions/webhook.ts
index c2c9f8c565..624f3488d9 100644
--- a/apps/web/pages/api/integrations/subscriptions/webhook.ts
+++ b/apps/web/pages/api/integrations/subscriptions/webhook.ts
@@ -4,8 +4,8 @@ import type Stripe from "stripe";
 
 import stripe from "@calcom/features/ee/payments/server/stripe";
 import { IS_PRODUCTION } from "@calcom/lib/constants";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import { HttpError as HttpCode } from "@calcom/lib/http-error";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import { prisma } from "@calcom/prisma";
 
 export const config = {
@@ -108,13 +108,13 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
       });
     }
   } catch (_err) {
-    const err = getErrorFromUnknown(_err);
+    const err = getServerErrorFromUnknown(_err);
     if (!err.message.includes("No credential found with subscription ID")) {
       console.error(`Webhook Error: ${err.message}`);
     }
-    res.status(err.statusCode ?? 500).send({
+    res.status(err.statusCode).send({
       message: err.message,
-      stack: IS_PRODUCTION ? undefined : err.stack,
+      stack: IS_PRODUCTION ? undefined : err.cause?.stack,
     });
     return;
   }
diff --git a/packages/app-store/alby/api/webhook.ts b/packages/app-store/alby/api/webhook.ts
index 760b4c7315..a16f9af219 100644
--- a/packages/app-store/alby/api/webhook.ts
+++ b/packages/app-store/alby/api/webhook.ts
@@ -6,8 +6,8 @@ import { handlePaymentSuccess } from "@calcom/app-store/_utils/payments/handlePa
 import { albyCredentialKeysSchema } from "@calcom/app-store/alby/lib";
 import parseInvoice from "@calcom/app-store/alby/lib/parseInvoice";
 import { IS_PRODUCTION } from "@calcom/lib/constants";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import { HttpError as HttpCode } from "@calcom/lib/http-error";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import prisma from "@calcom/prisma";
 
 export const config = {
@@ -90,11 +90,11 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
 
     return await handlePaymentSuccess(payment.id, payment.bookingId);
   } catch (_err) {
-    const err = getErrorFromUnknown(_err);
+    const err = getServerErrorFromUnknown(_err);
     console.error(`Webhook Error: ${err.message}`);
-    return res.status(err.statusCode || 500).send({
+    return res.status(err.statusCode).send({
       message: err.message,
-      stack: IS_PRODUCTION ? undefined : err.stack,
+      stack: IS_PRODUCTION ? undefined : err.cause?.stack,
     });
   }
 }
diff --git a/packages/app-store/btcpayserver/api/webhook.ts b/packages/app-store/btcpayserver/api/webhook.ts
index 05465a1bb9..c95a43b536 100644
--- a/packages/app-store/btcpayserver/api/webhook.ts
+++ b/packages/app-store/btcpayserver/api/webhook.ts
@@ -5,8 +5,8 @@ import { z } from "zod";
 
 import { handlePaymentSuccess } from "@calcom/app-store/_utils/payments/handlePaymentSuccess";
 import { IS_PRODUCTION } from "@calcom/lib/constants";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import { HttpError as HttpCode } from "@calcom/lib/http-error";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import { PrismaBookingPaymentRepository as BookingPaymentRepository } from "@calcom/lib/server/repository/PrismaBookingPaymentRepository";
 
 import appConfig from "../config.json";
@@ -90,11 +90,10 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
     await handlePaymentSuccess(payment.id, payment.bookingId);
     return res.status(200).json({ success: true });
   } catch (_err) {
-    const err = getErrorFromUnknown(_err);
-    const statusCode = err instanceof HttpCode ? err.statusCode : 500;
-    return res.status(statusCode).send({
+    const err = getServerErrorFromUnknown(_err);
+    return res.status(err.statusCode).send({
       message: err.message,
-      stack: IS_PRODUCTION ? undefined : err.stack,
+      stack: IS_PRODUCTION ? undefined : err.cause?.stack,
     });
   }
 }
diff --git a/packages/app-store/hitpay/api/webhook.ts b/packages/app-store/hitpay/api/webhook.ts
index ccf818c8c3..c472801304 100644
--- a/packages/app-store/hitpay/api/webhook.ts
+++ b/packages/app-store/hitpay/api/webhook.ts
@@ -4,8 +4,8 @@ import type z from "zod";
 
 import { handlePaymentSuccess } from "@calcom/app-store/_utils/payments/handlePaymentSuccess";
 import { IS_PRODUCTION } from "@calcom/lib/constants";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import { HttpError as HttpCode } from "@calcom/lib/http-error";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import prisma from "@calcom/prisma";
 
 import type { hitpayCredentialKeysSchema } from "../lib/hitpayCredentialKeysSchema";
@@ -111,11 +111,11 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
     }
     return await handlePaymentSuccess(payment.id, payment.bookingId);
   } catch (_err) {
-    const err = getErrorFromUnknown(_err);
+    const err = getServerErrorFromUnknown(_err);
     console.error(`Webhook Error: ${err.message}`);
     return res.status(200).send({
       message: err.message,
-      stack: IS_PRODUCTION ? undefined : err.stack,
+      stack: IS_PRODUCTION ? undefined : err.cause?.stack,
     });
   }
 }
diff --git a/packages/app-store/paypal/api/webhook.ts b/packages/app-store/paypal/api/webhook.ts
index 796276d603..f049b87812 100644
--- a/packages/app-store/paypal/api/webhook.ts
+++ b/packages/app-store/paypal/api/webhook.ts
@@ -6,8 +6,8 @@ import { handlePaymentSuccess } from "@calcom/app-store/_utils/payments/handlePa
 import { paypalCredentialKeysSchema } from "@calcom/app-store/paypal/lib";
 import Paypal from "@calcom/app-store/paypal/lib/Paypal";
 import { IS_PRODUCTION } from "@calcom/lib/constants";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import { HttpError as HttpCode } from "@calcom/lib/http-error";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import prisma from "@calcom/prisma";
 
 export const config = {
@@ -92,11 +92,11 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
       return await handlePaypalPaymentSuccess(parsedPayload, bodyAsString, parseHeaders.data);
     }
   } catch (_err) {
-    const err = getErrorFromUnknown(_err);
+    const err = getServerErrorFromUnknown(_err);
     console.error(`Webhook Error: ${err.message}`);
     res.status(200).send({
       message: err.message,
-      stack: IS_PRODUCTION ? undefined : err.stack,
+      stack: IS_PRODUCTION ? undefined : err.cause?.stack,
     });
     return;
   }
diff --git a/packages/app-store/stripepayment/lib/PaymentService.ts b/packages/app-store/stripepayment/lib/PaymentService.ts
index 8045d27fb9..cb1d1bc42b 100644
--- a/packages/app-store/stripepayment/lib/PaymentService.ts
+++ b/packages/app-store/stripepayment/lib/PaymentService.ts
@@ -5,9 +5,9 @@ import z from "zod";
 import { sendAwaitingPaymentEmailAndSMS } from "@calcom/emails/email-manager";
 import { BookingRepository } from "@calcom/features/bookings/repositories/BookingRepository";
 import { ErrorCode } from "@calcom/lib/errorCodes";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import { ErrorWithCode } from "@calcom/lib/errors";
 import logger from "@calcom/lib/logger";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import { safeStringify } from "@calcom/lib/safeStringify";
 import prisma from "@calcom/prisma";
 import type { Booking, Payment, PaymentOption, Prisma } from "@calcom/prisma/client";
@@ -368,7 +368,7 @@ export class PaymentService implements IAbstractPaymentService {
       });
       return updatedPayment;
     } catch (e) {
-      const err = getErrorFromUnknown(e);
+      const err = getServerErrorFromUnknown(e);
       throw err;
     }
   }
diff --git a/packages/app-store/vital/api/webhook.ts b/packages/app-store/vital/api/webhook.ts
index 73599a104c..50ae8d7168 100644
--- a/packages/app-store/vital/api/webhook.ts
+++ b/packages/app-store/vital/api/webhook.ts
@@ -3,9 +3,9 @@ import queue from "queue";
 
 import dayjs from "@calcom/dayjs";
 import { IS_PRODUCTION } from "@calcom/lib/constants";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import { HttpError as HttpCode } from "@calcom/lib/http-error";
 import logger from "@calcom/lib/logger";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import prisma from "@calcom/prisma";
 import type { Prisma } from "@calcom/prisma/client";
 import { BookingStatus } from "@calcom/prisma/enums";
@@ -100,7 +100,7 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
             return;
           }
 
-          if (!event.data.hasOwnProperty(parameterFilter)) {
+          if (!Object.prototype.hasOwnProperty.call(event.data, parameterFilter)) {
             res.status(500).json({ message: "Selected param not available" });
             return;
           }
@@ -141,7 +141,7 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
                 );
               }
               await q.start();
-            } catch (error) {
+            } catch {
               throw new Error("Failed to reschedule bookings");
             }
           }
@@ -155,11 +155,11 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
     }
     return res.status(200).json({ body: req.body });
   } catch (_err) {
-    const err = getErrorFromUnknown(_err);
+    const err = getServerErrorFromUnknown(_err);
     console.error(`Webhook Error: ${err.message}`);
-    res.status(err.statusCode ?? 500).send({
+    res.status(err.statusCode).send({
       message: err.message,
-      stack: IS_PRODUCTION ? undefined : err.stack,
+      stack: IS_PRODUCTION ? undefined : err.cause?.stack,
     });
     return;
   }
diff --git a/packages/emails/templates/_base-email.ts b/packages/emails/templates/_base-email.ts
index a9b192c777..703e9669bf 100644
--- a/packages/emails/templates/_base-email.ts
+++ b/packages/emails/templates/_base-email.ts
@@ -3,9 +3,9 @@ import { z } from "zod";
 
 import dayjs from "@calcom/dayjs";
 import { FeaturesRepository } from "@calcom/features/flags/features.repository";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import isSmsCalEmail from "@calcom/lib/isSmsCalEmail";
 import { serverConfig } from "@calcom/lib/serverConfig";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import { setTestEmail } from "@calcom/lib/testEmails";
 import { prisma } from "@calcom/prisma";
 
@@ -77,7 +77,7 @@ export default class BaseEmail {
         payloadWithUnEscapedSubject,
         (_err, info) => {
           if (_err) {
-            const err = getErrorFromUnknown(_err);
+            const err = getServerErrorFromUnknown(_err);
             this.printNodeMailerError(err);
             reject(err);
           } else {
diff --git a/packages/features/bookings/lib/service/RegularBookingService.ts b/packages/features/bookings/lib/service/RegularBookingService.ts
index 8b5fd15f44..36ccdebba6 100644
--- a/packages/features/bookings/lib/service/RegularBookingService.ts
+++ b/packages/features/bookings/lib/service/RegularBookingService.ts
@@ -61,7 +61,7 @@ import { groupHostsByGroupId } from "@calcom/lib/bookings/hostGroupUtils";
 import { shouldIgnoreContactOwner } from "@calcom/lib/bookings/routing/utils";
 import { DEFAULT_GROUP_ID } from "@calcom/lib/constants";
 import { ErrorCode } from "@calcom/lib/errorCodes";
-import { getErrorFromUnknown, ErrorWithCode } from "@calcom/lib/errors";
+import { ErrorWithCode } from "@calcom/lib/errors";
 import { extractBaseEmail } from "@calcom/lib/extract-base-email";
 import getOrgIdFromMemberOrTeamId from "@calcom/lib/getOrgIdFromMemberOrTeamId";
 import { getTeamIdFromEventType } from "@calcom/lib/getTeamIdFromEventType";
@@ -69,6 +69,7 @@ import { HttpError } from "@calcom/lib/http-error";
 import { criticalLogger } from "@calcom/lib/logger.server";
 import { getPiiFreeCalendarEvent, getPiiFreeEventType } from "@calcom/lib/piiFreeData";
 import { safeStringify } from "@calcom/lib/safeStringify";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import { getTranslation } from "@calcom/lib/server/i18n";
 import { getTimeFormatStringFromUserTimeFormat } from "@calcom/lib/timeFormat";
 import { distributedTracing } from "@calcom/lib/tracing/factory";
@@ -1844,9 +1845,9 @@ async function handler(
       };
     }
   } catch (_err) {
-    const err = getErrorFromUnknown(_err);
+    const err = getServerErrorFromUnknown(_err);
     tracingLogger.error(`Booking ${eventTypeId} failed`, "Error when saving booking to db", err.message);
-    if (err.code === "P2002") {
+    if (err.cause && typeof err.cause === "object" && "code" in err.cause && err.cause.code === "P2002") {
       throw new HttpError({
         statusCode: 409,
         message: ErrorCode.BookingConflict,
diff --git a/packages/features/ee/payments/api/webhook.ts b/packages/features/ee/payments/api/webhook.ts
index 28b9d6e1cf..f3832de3b5 100644
--- a/packages/features/ee/payments/api/webhook.ts
+++ b/packages/features/ee/payments/api/webhook.ts
@@ -14,10 +14,10 @@ import stripe from "@calcom/features/ee/payments/server/stripe";
 import { getPlatformParams } from "@calcom/features/platform-oauth-client/get-platform-params";
 import { PlatformOAuthClientRepository } from "@calcom/features/platform-oauth-client/platform-oauth-client.repository";
 import { IS_PRODUCTION } from "@calcom/lib/constants";
-import { getErrorFromUnknown } from "@calcom/lib/errors";
 import { HttpError as HttpCode } from "@calcom/lib/http-error";
 import logger from "@calcom/lib/logger";
 import { safeStringify } from "@calcom/lib/safeStringify";
+import { getServerErrorFromUnknown } from "@calcom/lib/server/getServerErrorFromUnknown";
 import { prisma } from "@calcom/prisma";
 import type { Prisma } from "@calcom/prisma/client";
 import { BookingStatus } from "@calcom/prisma/enums";
@@ -180,11 +180,11 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
       });
     }
   } catch (_err) {
-    const err = getErrorFromUnknown(_err);
+    const err = getServerErrorFromUnknown(_err);
     console.error(`Webhook Error: ${err.message}`);
-    res.status(err.statusCode ?? 500).send({
+    res.status(err.statusCode).send({
       message: err.message,
-      stack: IS_PRODUCTION ? undefined : err.stack,
+      stack: IS_PRODUCTION ? undefined : err.cause?.stack,
     });
     return;
   }
diff --git a/packages/lib/errors.ts b/packages/lib/errors.ts
index a97dcbf618..e7575ffdea 100644
--- a/packages/lib/errors.ts
+++ b/packages/lib/errors.ts
@@ -13,17 +13,34 @@ export class ErrorWithCode extends Error {
       get(_, prop: string) {
         if (prop in ErrorCode) {
           const code = ErrorCode[prop as keyof typeof ErrorCode];
-          return (message?: string, data?: Record<string, any>) => new ErrorWithCode(code, message, data);
+          return (message?: string, data?: Record<string, unknown>) => new ErrorWithCode(code, message, data);
         }
         throw new Error(`Unknown error code: ${prop}`);
       },
     }) as unknown as Record<
       keyof typeof ErrorCode,
-      (message?: string, data?: Record<string, any>) => ErrorWithCode
+      (message?: string, data?: Record<string, unknown>) => ErrorWithCode
     >;
   }
 }
 
+/**
+ * Converts unknown error types to Error objects.
+ * 
+ * @deprecated For server-side code, use `getServerErrorFromUnknown` from `@calcom/lib/server/getServerErrorFromUnknown` instead.
+ * This function should only be used in client-side or isomorphic code (React components, shared utilities).
+ * 
+ * Use this function when:
+ * - You're in a React component that runs on the client
+ * - You're in shared/isomorphic code that cannot import server-only dependencies
+ * - You only need a basic Error object without HTTP status code mapping
+ * 
+ * For server-side error handling (API routes, tRPC handlers, webhooks), use `getServerErrorFromUnknown`
+ * which provides proper HTTP status code mapping, error redaction, and handles Zod/Prisma/Stripe errors.
+ * 
+ * @param cause - The unknown error to convert
+ * @returns An Error object with optional statusCode and code properties
+ */
 export function getErrorFromUnknown(cause: unknown): Error & { statusCode?: number; code?: string } {
   if (cause instanceof Error) {
     return cause;
diff --git a/packages/lib/server/getServerErrorFromUnknown.ts b/packages/lib/server/getServerErrorFromUnknown.ts
index dcbdae850b..32cdcebfa7 100644
--- a/packages/lib/server/getServerErrorFromUnknown.ts
+++ b/packages/lib/server/getServerErrorFromUnknown.ts
@@ -33,6 +33,12 @@ function parseZodErrorIssues(issues: ZodIssue[]): string {
     .join("; ");
 }
 
+/**
+ * Converts unknown error types to HttpError with proper status code mapping and error redaction.
+ * SERVER-ONLY: This function imports Prisma and Stripe schemas and should only be used in server-side code.
+ * Use in API routes, tRPC handlers, webhooks, and server-side services.
+ * For client-side code, use getErrorFromUnknown from @calcom/lib/errors instead.
+ */
 export function getServerErrorFromUnknown(cause: unknown): HttpError {
   if (isZodError(cause)) {
     return new HttpError({