SKILL-009 Data modeling and migrations Locked skill

Audit logs

An audit log is append-only: never update or delete a row, and never trust the client for the actor.

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What this skill helps you build

Record who did what, to which record, and when — an append-only trail you can actually defend in an audit.

The production takeaway

An audit log is append-only: never update or delete a row, and never trust the client for the actor.

02

Inside this skill

The full skill expands these implementation areas with decisions, edge cases, prompts, tests, and framework-specific code.

Data modeling and migrations
What this helps you build

A tamper evident audit trail : a record of every meaningful action in your app — who performed it, what changed, on which record, and when. The kind of log you can hand to a securi

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Data modeling and migrations
When to use this

Use this when your SaaS touches anything sensitive: money, permissions, customer data, or anything a regulator SOC 2, HIPAA, GDPR will ask about. Concretely, reach for an audit log

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Data modeling and migrations
The core idea

An audit log is an append only stream of facts. You only ever INSERT . You never UPDATE and never DELETE an entry — a log you can quietly edit is not evidence of anything. Each ent

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03

Unlock the full implementation

Paid access includes the complete skill body, implementation prompt, common mistakes, production checklist, and code examples where this skill includes them.