Praxis Webhooks

Praxis (Praxis Tech, the "Cashier" payment orchestration platform) signs every outbound webhook with a SHA-384 hex digest in the lowercase gt-authentication header. This is not an HMAC and not Standard Webhooks: Praxis takes a fixed, per-webhook-type list of field values in the documented order, concatenates them into one string, appends your Merchant Secret, and hashes the result with sha384. Your endpoint must reply 200 with a { "status": 0, ... } body and sign that acknowledgement with the external-request-signature header.

When to Use This Skill

• How do I receive Praxis / Praxis Tech / Cashier webhooks?
• How do I verify the gt-authentication signature on a Praxis webhook?
• Why is my Praxis SHA-384 signature verification failing?
• How do I sign the Praxis acknowledgement (external-request-signature)?
• How do I handle Payment Notification transaction_status (pending, approved, rejected, error)?
• How do I handle a Praxis Subscription Notification event?