How to Handle Webhooks with Next.js App Router#

Scope: This guide focuses specifically on webhook patterns for Next.js App Router route handlers. For a comprehensive overview including Pages Router patterns, see the Complete Guide to Webhooks in Next.js.

Handling webhooks in Next.js App Router applications typically starts simple enough—create a route handler, verify signatures, process the payload. The setup works fine during initial development and low-volume testing.

Over time, though, webhook handling becomes one of those parts of the application that you’d prefer not to touch. Silent failures start appearing, retry logic gets complicated, and debugging becomes a process of correlating provider logs with your application logs, often finding gaps where events seem to disappear.

When this keeps happening, it’s usually less about handler logic and more about missing persistence and visibility between the provider and your app.

Why webhook deliveries fail silently in Next.js App Router#

Next.js App Router webhook handlers run in serverless environments where several production issues commonly surface:

• Webhook deliveries that return 200 to the provider but never complete processing due to runtime timeouts
• Duplicate processing from provider retries without clear delivery timestamps or correlation IDs
• Memory or execution time limits causing partial processing that’s difficult to detect
• Network issues between the provider and your deployment that result in incomplete requests
• Handler errors that occur after the HTTP response, making them invisible to the sending service
• Cold start delays causing timeouts on the provider side, triggering unnecessary retries

These issues tend to manifest as missing data or inconsistent state rather than obvious errors, making them particularly annoying to track down.

If this is a low-volume application where occasional missed events are acceptable, this complexity may not matter yet.

Next.js App Router serverless constraints#

The App Router’s serverless execution model contributes to webhook reliability challenges in specific ways:

Request lifecycle limits: Serverless functions have strict time constraints. Complex webhook processing that works locally may timeout in production, but the timeout often happens after sending a response to the provider.

Execution environment: Cold starts can delay webhook processing enough to trigger provider timeouts, even when your handler eventually runs successfully.

Error visibility: Errors that occur during or after response sending don’t always surface in logs the same way they would in a persistent server environment.

Deployment boundaries: The abstraction between your route handler and the actual serverless infrastructure makes it harder to understand exactly what happens during edge cases or partial failures.

How HookRelay addresses webhook reliability#

HookRelay functions as a buffer between external webhook providers and your Next.js application. Instead of providers sending webhooks directly to your API routes, they send to HookRelay endpoints, which then forward events to your application while maintaining delivery records and retry logic.

The architectural change decouples webhook delivery reliability from your business logic. Instead of Stripe retrying your serverless function directly when timeouts occur, HookRelay handles the initial delivery, then manages forwarding and retries to your application with full visibility into what’s happening.

See how delivery attempts are tracked for the specifics of what gets recorded during webhook processing.

What this looks like in a Next.js app#

• Point your webhook provider at a HookRelay endpoint instead of directly at your API route
• HookRelay receives the webhook, records it, and forwards it to your Next.js handler
• Failed or incomplete deliveries remain visible and can be replayed without provider involvement
• Your route handler focuses on processing logic rather than delivery reliability concerns
• Retries and failure inspection happen outside your application’s request lifecycle

Stripe webhook specifics#

When working with Stripe webhooks in Next.js App Router applications, a few additional considerations apply:

Signature verification still happens in your route handler, but HookRelay preserves the original Stripe signatures so verification works normally.

Retry behavior from Stripe becomes less critical since HookRelay handles its own retry logic for forwarding events to your application.

Idempotency remains important in your handler logic, as HookRelay’s replay functionality means events might be reprocessed during debugging or recovery scenarios.

When this approach makes sense#

This architectural pattern becomes useful once webhooks represent critical application functionality that needs operational visibility. For applications where webhook processing affects user-facing features, billing, or data consistency, the ability to inspect and replay failed deliveries often justifies the additional infrastructure.

For early-stage applications or prototypes where webhook reliability isn’t yet operationally important, the added complexity may not provide immediate value.

Reducing webhook maintenance overhead#

HookRelay shifts webhook reliability concerns from application code to infrastructure. Your Next.js route handlers can focus on processing webhook payloads rather than managing delivery edge cases, retry logic, or debugging silent failures.

The persistent record of webhook attempts and outcomes means that when issues do occur, you can inspect exactly what happened and replay events after fixing problems, rather than waiting for the next occurrence or asking providers to resend webhooks.

View webhook failure tracking to see how delivery issues become visible and actionable.