Permissions by Subject, Role, and Context. Model in-memory
Switch branches/tags
Nothing to show
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.
lib Subject Roles in contexts, with tests Jan 12, 2013
test Subject Roles in contexts, with tests Jan 12, 2013
.gitignore Initial Commit Jan 12, 2013
LICENSE Fixing README Jan 12, 2013


Permissions by Subject, Role, and Context. It uses an in-memory model.


  • Subject: A person or automated agent
  • Role: Job function or title which defines an authority level
  • Permission: An approval of a mode of access to a resource
  • Context: A set of values to describe the context where permissions and other attributes are assigned

Source Role-based access control. The main difference is that SimplePermissions manages contexts: roles and permissions are assigned in context, i.e., a subject can have role manager in the context { application: 'Sales' } and he/she can have role user in the context { application: 'Purchases' }. A context can have many properties, i.e. { application: 'Sales', country: 'Argentina' }.

Subjects and Roles are identified by a simple (and unique) name. Permissions are simple strings. Contexts are simple objects with properties and their values.


Via npm on Node:

npm install simplepermissions


Reference in your program:

var simplepermissions = require('simplepermissions');
var engine = simplepermissions.createEngine();
var subjects = engine.subjects();
var roles = engine.roles();

Grant subject permissions, in a context:

subjects.grantPermission(subjectId, permission(s), context);


subjects.grantPermission('adam', 'create account', 
    { application: 'Accounting' });
subjects.grantPermission('alice', 'print invoice', 
    { application: 'Sales', country: 'Argentina' });
subjects.grantPermission('albert', ['create order', 'print order'], 
    { application: 'Purchases', country: 'Australia' });

Retrieve subject granted permissions in a context:

var permissions = subjects.grantedPermissions('adam', { application: 'Accounting' });
permissions.forEach(function (permission) { console.log(permission); });

Grant role permissions, in a context:

roles.grantPermission(roleId, permission(s), context);


roles.grantPermission('accountant', 'create account', 
    { application: 'Accounting' });
roles.grantPermission('clerk', 'print invoice', 
    { application: 'Sales', country: 'Argentina' });
roles.grantPermission('manager', ['create order', 'print order'], 
    { application: 'Purchases', country: 'Australia' });

Retrieve role granted permissions in a context:

var permissions = roles.grantedPermissions('accountant', { application: 'Accounting' });
permissions.forEach(function (permission) { console.log(permission); });

The returned value is an array with the permission values. If no permission was granted, the empty array [] is returned.

Add a role to a subject in a context:

subjects.addRole('adam', 'accountant', { application: 'Accounting' });

Get roles of a subject in context:

var adamroles = subjects.getRoles('adam', { application: 'Accounting' });

The returned value is an array with the subject roles for that context. If no roles as assigned to that context, the empty array [] is returned.


Persistence is an orthogonal problem. You must reify the engine from your persistence store, and update their values.


git clone git://
cd SimplePermissions
npm install
npm test



To do

  • Samples
  • Revoke permissions
  • Remove permissions
  • Better context organization and retrieval, to support thousands of values
  • Permissions inherited by Context


  • 0.0.1: Published
  • 0.0.2: Under development, in master


Feel free to file issues and submit pull requests — contributions are welcome.

If you submit a pull request, please be sure to add or update corresponding test cases, and ensure that npm test continues to pass.