v0 integration

Stripe Webhook Signature Verification Failing

Your v0-generated Next.js application receives Stripe webhook events but fails to verify their signatures, returning 400 errors or throwing 'Webhook signature verification failed' exceptions. Payments are processed by Stripe but your application never confirms them, leaving orders in a pending state and customers confused.

Stripe signs every webhook event with a signature derived from the raw request body and your webhook signing secret. If the body is modified in any way before verification (such as being parsed as JSON), or if the signing secret is incorrect, verification fails. This is a critical security feature that prevents attackers from sending fake webhook events to your application.

This is one of the most common Stripe integration issues because Next.js API routes automatically parse the request body as JSON, which modifies the raw body that Stripe's verification expects.

Error Messages You Might See

Stripe webhook signature verification failed No signatures found matching the expected signature for payload Webhook Error: Unexpected token in JSON at position 0 stripe.webhooks.constructEvent is not a function 400 Bad Request on /api/webhook
Stripe webhook signature verification failedNo signatures found matching the expected signature for payloadWebhook Error: Unexpected token in JSON at position 0stripe.webhooks.constructEvent is not a function400 Bad Request on /api/webhook

Common Causes

  • Body pre-parsed by Next.js — Next.js API routes parse JSON body automatically, but Stripe verification requires the raw body bytes
  • Wrong webhook secret — using the API secret key (sk_...) instead of the webhook signing secret (whsec_...)
  • Local vs production secret mismatch — Stripe CLI uses a different signing secret than the dashboard webhook endpoint
  • App Router body handling — Next.js App Router route handlers consume the body stream, making it unavailable for Stripe verification
  • Middleware modifying request — authentication or logging middleware reading the request body before the webhook handler

How to Fix It

  1. Disable body parsing — for Pages Router: export const config = { api: { bodyParser: false } }
  2. Read raw body in App Router — use const body = await request.text() to get the raw body string before any JSON parsing
  3. Use correct signing secret — get the webhook signing secret (whsec_...) from Stripe Dashboard > Webhooks > your endpoint > Signing secret
  4. Verify with Stripe SDK — use stripe.webhooks.constructEvent(body, sig, webhookSecret) with the raw body string
  5. Test with Stripe CLI — run stripe listen --forward-to localhost:3000/api/webhook and use the provided signing secret for local testing
  6. Return 200 quickly — process webhook asynchronously and return 200 immediately to avoid Stripe retry storms

Real developers can help you.

Jared Hasson Jared Hasson Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever Mehdi Ben Haddou Mehdi Ben Haddou - Founder of Chessigma (1M+ users) & many small projects - ex Founding Engineer @Uplane (YC F25) - ex Software Engineer @Amazon and @Booking.com Stanislav Prigodich Stanislav Prigodich 15+ years building iOS and web apps at startups and enterprise companies. I want to use that experience to help builders ship real products - when something breaks, I'm here to fix it. Alvin Voo Alvin Voo I’ve watched the tech landscape evolve over the last decade—from the structured days of Java Server Pages to the current "wild west" of Agentic-driven development. While AI can "vibe" a frontend into existence, I specialize in the architecture that keeps it from collapsing. My expertise lies in the critical backend infrastructure: the parts that must be fast, secure, and scalable. I thrive on high-pressure environments, such as when I had only three weeks to architect and launch an Ethereum redemption system with minimal prior crypto knowledge, turning it into a major revenue stream. What I bring to your project: Forensic Debugging: I don't just "patch" bugs; I use tools like Datadog and Explain Analyzers to map out bottlenecks and resolve root causes—like significantly reducing memory usage by optimizing complex DB joins. Full-Stack Context: Deep experience in Node.js and React, ensuring backends play perfectly with mobile and web teams. Sanity in the Age of AI: I bridge the gap between "best practices" and modern speed, ensuring your project isn't just built fast, but built to last. Anthony Akpan Anthony Akpan Developer with 8 years of experience building softwares fro startups PawelPloszaj PawelPloszaj I'm fronted developer with 10+ years of experience with big projects. I have small backend background too Matthew Butler Matthew Butler Systems Development Engineer @ Amazon Web Services Antriksh Narang Antriksh Narang 5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies. Dor Yaloz Dor Yaloz SW engineer with 6+ years of experience, I worked with React/Node/Python did projects with React+Capacitor.js for ios Supabase expert Luca Liberati Luca Liberati I work on monoliths and microservices, backends and frontends, manage K8s clusters and love to design apps architecture

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help

Frequently Asked Questions

Why does webhook verification fail even with the correct secret?

Most likely the request body was parsed as JSON before verification. Stripe needs the raw body bytes. Disable body parsing with config = { api: { bodyParser: false } }.

Where do I find my webhook signing secret?

Go to Stripe Dashboard > Developers > Webhooks > click your endpoint > Signing secret. It starts with whsec_. Do not use your API key (sk_...).

How do I test webhooks locally?

Install Stripe CLI, run 'stripe listen --forward-to localhost:3000/api/webhook', and use the signing secret it outputs (whsec_...) for local testing.

Related v0 Issues

Can't fix it yourself?
Real developers can help.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help