Firebase Security Rulesplat_iosplat_androidplat_webplat_node

Use our flexible, extensible Firebase Security Rules to secure your data in Cloud Firestore, Firebase Realtime Database, and Cloud Storage.

Firebase Security Rules stand between your data and malicious users. You can write simple or complex rules that protect your app's data to the level of granularity that your specific app requires.

Firebase Security Rules leverage extensible, flexible configuration languages to define what data your users can access for Realtime Database, Cloud Firestore, and Cloud Storage. Firebase Realtime Database Rules leverage JSON in rule definitions, while Cloud Firestore Security Rules and Firebase Security Rules for Cloud Storage leverage a unique language built to accommodate more complex rules-specific structures.

Learn more about how to set up Rules for the specific Firebase products you use in your app, and how Rules behavior differs across Firebase products.

Key capabilities

Flexibility Write custom rules that make sense for your app's structure and behavior. Rules use languages that allow you to leverage your own data to authorize access.
Granularity Your rules can be as broad or as narrow as you need.
Independent security Because Rules are defined outside of your app (in the Firebase console or Firebase CLI), clients aren't responsible for enforcing security, bugs don't compromise data, and your data is always protected.

How do they work?

Firebase Security Rules work by matching a pattern against database paths, and then applying custom conditions to allow access to data at those paths. All Rules across Firebase products have a path-matching component and a conditional statement allowing read or write access. You must define Rules for each Firebase product you use in your app.

For Cloud Firestore and Cloud Storage, Rules use the following syntax:

service <<name>> {
  // Match the resource path.
  match <<path>> {
    // Allow the request if the following conditions are true.
    allow <<methods>> : if <<condition>>
  }
}

For Realtime Database, JSON-based Rules use the following syntax:

{
  "rules": {
    "<<path>>": {
    // Allow the request if the condition for each method is true.
      ".read": <<condition>>,
      ".write": <<condition>>
    }
  }
}

Rules are applied as OR statements, not AND statements. Consequently, if multiple rules match a path, and any of the matched conditions grants access, Rules grant access to the data at that path. Therefore, if a broad rule grants access to data, you can't restrict with a more specific rule. You can, however, avoid this problem by making sure your Rules don't overlap too much. Firebase Security Rules flag overlaps in your matched paths as compiler warnings.

Firebase Security Rules can also leverage Authentication to grant user-based permissions, and the conditions you set can be very basic or incredibly complex. Learn more about Rules language and behavior before you start writing Rules.

Implementation path

Integrate the product SDKs Set up Cloud Firestore, Cloud Storage, or Realtime Database for your app.
Write your Firebase Security Rules Learn more about how Rules work and set up some basic Rules
Test your Firebase Security Rules Use the Realtime Database and Cloud Firestore emulators to test your app's behavior and validate your rules before you deploy them to production.
Deploy your Firebase Security Rules Use the Firebase console or the Firebase CLI to deploy your rules to production.

Next steps

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