nmi-webhooks

name	nmi-webhooks
description	Receive and verify NMI (Network Merchants) webhooks. Use when setting up NMI webhook handlers, debugging Webhook-Signature verification, or handling transaction events like transaction.sale.success, transaction.auth.success, transaction.refund.success, and transaction.void.success. Note: NMI does NOT use Standard Webhooks — the Webhook-Signature header is "t=<nonce>,s=<sig>" (comma-separated) where t is a NONCE (not a Unix timestamp), and the signature is HMAC-SHA256 over "<nonce>.<raw_body>", lowercase hex.
license	MIT
metadata	{"author":"hookdeck","version":"0.1.0","repository":"https://github.com/hookdeck/webhook-skills"}

NMI Webhooks

When to Use This Skill

• How do I receive NMI (Network Merchants) webhooks?
• How do I verify the NMI Webhook-Signature header?
• Why is my NMI webhook signature verification failing?
• How do I handle transaction.sale.success, transaction.auth.success, transaction.refund.success, or transaction.void.success events?
• What is the t= value in the NMI signature header — is it a timestamp?

How NMI Webhooks Work (Read This First)

NMI does not use the Standard Webhooks spec. Each delivery carries a single custom header:

Webhook-Signature: t=f3c1e9a2b7d84c15,s=9b7c...e10a