How to Handle Webhook Retries and Duplicates in Next.js
Scope: This guide focuses specifically on implementing idempotent webhook handlers and deduplication strategies. For a comprehensive overview, see the Complete Guide to Webhooks in Next.js.
Next.js webhook retry handling works fine for simple cases—until production complexity kicks in. Your API route receives the webhook, processes it, and responds with a 200. The provider retries failed deliveries automatically. Everything seems straightforward.
The friction emerges over time: missed deliveries that looked successful, duplicate processing from retries you can’t identify, timeouts in serverless functions, and debugging failures through incomplete logs. You find yourself not wanting to touch the webhook handler because it feels fragile, even when the core logic is solid.
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 retries become problematic in Next.js
The retry patterns that work in long-running server applications don’t map cleanly to Next.js serverless execution. Each webhook delivery is an isolated function invocation with limited execution time and no persistent state between requests.
When a webhook delivery fails—whether from a timeout, an unhandled error, or a database connection issue—the provider implements its own retry logic. This creates several practical problems: you can’t distinguish retries from original deliveries without building state tracking, failed deliveries often leave no trace in your application logs, and debugging requires correlating timestamps across different systems.
The serverless execution model means your handler can’t maintain context about previous delivery attempts. If the same webhook gets retried three times, each invocation looks identical to your application. Building idempotency and replay logic directly into API routes works, but it mixes delivery reliability concerns with business logic.
Common production scenarios
Webhook deliveries that return 200 but never trigger your business logic, usually due to unhandled errors or database timeouts that occur after the HTTP response. Duplicate processing when retries succeed after the original delivery actually worked, but your app couldn’t respond quickly enough. Silent failures where the webhook provider stops retrying, but you have no visibility into why or when this happened.
Next.js deployment differences between local development and production serverless functions mean webhook behavior often differs between environments. Request timeout limits in serverless runtimes can cause deliveries to fail unpredictably under load, and debugging requires piecing together provider logs, function logs, and application logs across different systems.
If this is a low-volume app where occasional missed events are acceptable, this complexity may not matter yet.
How Next.js characteristics contribute
The serverless execution model means each webhook delivery starts with a cold or warm function invocation, subject to platform timeout limits. Your handler has no persistent connection to track delivery attempts or maintain retry state between invocations.
API routes abstract away much of the HTTP handling, which is convenient but can hide important details about delivery failures or timeout behavior. The deployment and runtime differences between development and production mean webhook retry behavior is difficult to reproduce locally.
These aren’t limitations of Next.js—they’re natural characteristics of the serverless model that affect how webhook reliability needs to be approached.
How HookRelay helps
HookRelay acts as a buffer between webhook providers and your Next.js application, handling delivery reliability and retry logic outside your serverless functions. Instead of providers retrying your API route directly, they deliver to HookRelay, which manages retries, failure tracking, and replay independently from your application code.
The delivery tracking maintains a complete record of webhook attempts, retries, and failures that persists regardless of your application’s execution environment. When deliveries fail, you can inspect the failure details and replay events after fixing the underlying issue without rebuilding infrastructure.
What this looks like in a Next.js app
- Point the webhook provider at a HookRelay endpoint instead of your API route
- HookRelay forwards successful deliveries to your handler and records all attempts
- Failed deliveries remain visible and replayable without cluttering your application logs
- Your API route focuses on business logic without building retry or tracking infrastructure
- Debugging happens through delivery history rather than correlating scattered logs
Stripe webhook considerations
Stripe webhook retry handling includes signature verification timing, exponential backoff retry schedules, and idempotency expectations around duplicate event processing. These patterns work well when you can maintain delivery state, but become more complex in serverless environments where each retry looks like a new request.
Stripe’s webhook retry behavior stops after several days of failed attempts, and their dashboard shows delivery attempts but not necessarily why your handler failed to process them successfully.
When this approach fits
This becomes useful once webhooks matter operationally—when missed events cause customer-facing problems or when debugging webhook issues takes significant development time. The additional infrastructure may be unnecessary for early prototypes or applications where webhook processing failures don’t impact core functionality.
For production applications where webhook reliability affects user experience or business processes, separating delivery concerns from application logic tends to reduce ongoing maintenance overhead.
The goal is to make webhook handling feel less fragile and more observable, without requiring significant changes to your existing Next.js API route structure.