Saas Payment Validation · henan6 bundle Plan, review, or audit engineering validation for behavior-affecting SaaS payment code and payment-capable releases. Use whenever a change touches checkout, billing state, subscriptions, entitlements, payment webhooks, reconciliation, provider APIs, payment persistence/concurrency, or release-candidate payment lifecycle behavior — even if the user does not use the word "validation". Use it to choose L1-L4 evidence, decide whether Level 4 is actually required, and keep real-time validation evidence trustworthy. Do not use for billing copy/CSS, pricing strategy, provider selection, or general payment questions with no engineering-validation decision in them.
