Securing Firebase
A Practical Checklist

Security starts in the data model

Firebase security is easier when the data model reflects access patterns. Keith Azodeh prefers to design collections and document shapes so that rules can express least privilege cleanly. If rules need complex logic to compensate for a messy model, the model is usually the problem.

Use least privilege by default

• Restrict reads and writes to the minimum required role.
• Do not assume the client is honest.
• Validate key fields in rules when possible.

Test rules like code

Rules should be tested with representative scenarios. A rule that "works" in manual testing can still have dangerous edge cases. Treat rules as part of the codebase and include them in the same quality bar.

Where these patterns show up

Firebase-backed patterns appear in projects like From Strangers. The goal is always the same: secure defaults, understandable rules, and a system that is safe to evolve.