Slack Webhooks When to Use This Skill - Setting up a Slack Events API webhook handler (Request URL) - Debugging verification failures - Handling the initial challenge from Slack - Processing events like , , , , or - Returning a 2xx response within 3 seconds to avoid Slack retries Essential Code (USE THIS) Slack signs every Events API request with HMAC-SHA256. The signed content is the literal string , and the result is sent as . Use the raw request body — parsing JSON before verifying will change byte ordering and break the signature. Slack Signature Verification (JavaScript) Express Webhook…