Firebase rules example.json

{
  "rules": {
    // Admin access.
    ".read": "auth.token.admin === true",
    ".write": "auth.token.admin === true",
    "admins": {
      ".read": "false",  // Only a cloud function or admins can update this.
      ".write": "false",  // Only a cloud function or admins can update this.
      "$index": {
        "email": {
          ".validate": "newData.isString()"
        }
      }
    },
    // User's personnal feeds.
    "feed": {
      "$uid": {
        ".read": "auth.uid === $uid",
        ".write": "auth.uid === $uid",
        "$postId": {
          ".validate": "newData.val() === true && newData.parent().parent().parent().child('posts').child($postId).exists()"
        }
      }
    },
    // List of all Posts.
    "posts": {
      ".read": true,
      ".indexOn": ["author/uid", "timestamp"], // Allow searching for posts by authors. Useful for deletion.
      "$postId": {
        ".write": "!data.exists() || data.exists() && auth.uid === data.child('author').child('uid').val()", // Allow new writes and allow updates and deletes to own posts.
        ".validate": "newData.child('author').child('uid').exists() && newData.child('text').exists()",
        "text": {
          ".validate": "newData.isString() && newData.val().length < 2000"
        },
        "timestamp": {
          ".validate": "newData.val() === now"
        },
        "client": {
          ".validate": "newData.val() === 'web' || newData.val() === 'ios' || newData.val() === 'android'"
        },
        "sanitized": {
          ".validate": "false" // Only a cloud function (admin mode) can update this.
        },
        "moderated": {
          ".validate": "false" // Only a cloud function (admin mode) can update this.
        },
        "author": {
          "uid": {
            ".validate": "auth.uid === newData.val()"
          },
          "full_name": {
            ".validate": "auth.token.name === newData.val() || (auth.token.name === null && newData.val() === 'Anonymous')"
          },
          "profile_picture": {
            ".validate": "true"
          }
        }
      }
    },
    // Post's comments.
    "comments": {
      ".read": true,
      "$postId": {
        ".indexOn": "author/uid", // Allow searching for comments by authors. Useful for deletion.
        ".write": "!newData.exists() && auth.uid === root.child('posts').child($postId).child('author').child('uid').val() && !newData.parent().parent().child('posts').child($postId).exists()", // Allow deletes from the post owner
        ".validate": "root.child('posts').child($postId).exists()", // Check that the post exists
        "$commentId": {
          ".write": "(!data.exists() || data.exists() && auth.uid === data.child('author').child('uid').val()) && (root.child('blocked').child(auth.uid).child(root.child('posts').child($postId).child('author').child('uid').val()).val() !== true)", // Can write new comments and edit/delete particular comment if you are the author.
          "text": {
            ".validate": "newData.isString() && newData.val().length < 2000"
          },
          "sanitized": {
            ".validate": "false" // Only a cloud function (admin mode) can update this.
          },
          "moderated": {
            ".validate": "false" // Only a cloud function (admin mode) can update this.
          },
          "timestamp": {
            ".validate": "newData.val() === now"
          },
          "author": {
            "uid": {
              ".validate": "auth.uid === newData.val()"
            },
            "full_name": {
              ".validate": "auth.token.name === newData.val() || (auth.token.name === null && newData.val() === 'Anonymous')"
            },
            "profile_picture": {
              ".validate": "true"
            },
            "$other": {
              ".validate": false
            }
          },
          "$other": {
            ".validate": false
          }
        }
      }
    },
    // Hashtag index.
    "hashtags": {
      ".read": true,
      ".write": false
    },
    // List of post's likes.
    "likes": {
      ".read": true,
      "$postId": {
        ".write": "!newData.exists() && auth.uid === root.child('posts').child($postId).child('author').child('uid').val() && !newData.parent().parent().child('posts').child($postId).exists()", // Allow deletes from the post owner
        ".validate": "root.child('posts').child($postId).exists()", // Check that the post exists
        "$uid": {
          ".write": "auth.uid === $uid",
          ".validate": "newData.val() === now"
        }
      }
    },
    // List of followers.
    "followers": {
      ".read": true,
      "$followedUid": {
        "$followerUid": {
          ".write": "auth.uid === $followerUid", // Can only add yourself as a follower
          ".validate": "newData.val() === true && newData.parent().parent().parent().child('people').child($followerUid).child('following').child($followedUid).exists()" // Makes sure /people/.../following is in sync
        }
      }
    },
    // Public profile information.
    "people": {
      ".indexOn": ["_search_index/full_name", "_search_index/reversed_full_name"],
      ".read": true,
      "$uid": {
        ".write": "auth.uid === $uid",
        "full_name": {
          ".validate": "auth.token.name === newData.val() || (auth.token.name === null && newData.val() === 'Anonymous')"
        },
        "profile_picture": {
          ".validate": "true"
        },
        "posts": {
          "$postId": {
            ".validate": "newData.val() === true && newData.parent().parent().parent().parent().child('posts').child($postId).exists()"
          }
        },
        "_search_index": {
          "full_name": {
            ".validate": "newData.isString()"
          },
          "reversed_full_name": {
            ".validate": "newData.isString()"
          }
        },
        "following": {
          "$followedUid": {
            ".validate": "newData.parent().parent().parent().parent().child('followers').child($followedUid).child($uid).val() === true" // Makes sure /followers is in sync
          }
        }
      }
    },
    // List of blocked users.
    "blocking": {
      "$blockerUid": {
        ".write": "auth.uid === $blockerUid", // Can only add yourself as a blocker
        ".read": "auth.uid === $blockerUid",
        "$blockedUid": {
          ".read": "auth.uid === $blockedUid",
          ".validate": "newData.val() === true && newData.parent().parent().parent().child('blocked').child($blockedUid).child($blockerUid).exists()" // Makes sure /blocked is in sync
        }
      }
    },
    // List of blocking users.
    "blocked": {
      "$blockedUid": {
        ".read": "auth.uid === $blockedUid",
        "$blockerUid": {
          ".read": "auth.uid === $blockerUid",
          ".write": "auth.uid === $blockerUid", // Can only add yourself as a blocker
          ".validate": "newData.val() === true && newData.parent().parent().parent().child('blocking').child($blockerUid).child($blockedUid).exists()" // Makes sure /blocker is in sync
        }
      }
    },
    // List of flagged posts.
    "postFlags": {
      "$postId": {
        ".validate": "root.child('posts').child($postId).exists()", // Check that the post exists
        "$uid": {
          ".write": "auth.uid === $uid",
          ".read": "auth.uid === $uid",
          ".validate": "newData.val() === true"
        }
      }
    },
    // List of flagged comments.
    "commentFlags": {
      "$postId": {
        ".validate": "root.child('posts').child($postId).exists()", // Check that the post exists
        "$commentId": {
          ".validate": "root.child('comments').child($postId).child($commentId).exists()", // Check that the comment exists
          "$uid": {
            ".write": "auth.uid === $uid",
            ".read": "auth.uid === $uid",
            ".validate": "newData.val() === true"
          }
        }
      }
    },
    // Privacy settings
    "privacy": {
      "$uid": {
        ".write": "auth.uid === $uid",
        ".read": "auth.uid === $uid",
        "data_processing": {
          ".validate": "newData.isBoolean()"
        },
        "content": {
          ".validate": "newData.isBoolean()"
        },
        "social": {
          ".validate": "newData.isBoolean()"
        },
        "$other": {
          ".validate": "false"
        }
      }
    },
    // Disallow all other attributes.
    "$other": {
      ".validate": false
    }
  }
}