Parse JSON string

I have a webhook that receives a JSON payload from Stripe and sometimes throws when the body is malformed. Parse the incoming body string into an object, validate the required fields customer_id and amount exist and are numbers, and if parsing fails respond 400 with a clear message so the caller can fix it.

Before I send this webhook handler to the ops team, make the payload validation easy to audit: place the parse and schema check at the top, surface the exact offending key and value, and call out where optional fields could be abused. Flag any try/catch that swallows errors without a 400 response.

A Stripe webhook started failing for some customers; the handler throws a SyntaxError when JSON.parse runs and I return 500 to Stripe. I don’t know if the problem is bad data from Stripe or an upstream proxy mangling the body. What is the most likely cause and the safest immediate change so we return a helpful 400 and log the raw body for debugging?

Every few weeks a third-party webhook arrives with broken JSON and I end up adding ad hoc fixes for each case. This wastes time and leaves us exposed. What process and simple code pattern should I make standard so incoming JSON is parsed defensively, validated against a schema, and incidents surface actionable debug info without leaking PII?