If you are deploying webhooks in Next.js 15 (App Router), Cloudflare Workers, or Hono, you have likely run into the infamous cryptographic verification failure.

On paper, the process is straightforward: your provider (Stripe, Clerk, or Lemon Squeezy) sends a POST request, you check the signature using your webhook secret, and you return a 200 OK.

In reality, modern frameworks make it incredibly painful to access the unmodified, byte-for-byte raw request body required to validate signatures.

The High-Pain Problem: Automated Parsing

Modern web frameworks love helper functions that automatically parse incoming JSON payloads into JavaScript objects.

However, cryptographic signature validation breaks if even a single space, newline, or character is modified during that parsing step.…