> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fga.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Modeling roles

> Various ways of modeling static and dynamic roles in FGA - both coarse and fine-grained.

Roles are a common way to group users and assign permissions to those groups. They can be used to simplify permission management, especially in larger systems where many users have similar access needs.

In this guide, we'll explore common approaches to modeling roles with Auth0 FGA.

## When to Use Each Approach

Before diving into implementation details, here's a quick guide to help you choose the right approach:

| Approach | Best For | Complexity | Flexibility | Example |
| - | - | - | - | - |
| **Relations as Roles** | Static, predefined roles | Low | Low | In all instances, company admins can view project information. |
| **Simple User-Defined Roles** | User-defined roles at org level | Medium | Medium | Company Acme creates an "Auditor" role that is configured to view project information for all projects. |
| **Role Assignments** | Instance-specific role assignments | High | High | In Company Acme, Anne can be a custom Auditor role for Projects 1 and 5, but Beth can be an Auditor on Project 3. |

## Approach 1: Relations as Roles

The simplest way to implement roles is to use directly assignable relations. They work well for roles that always exist and can be defined at development-time. Adding relations is straightforward, and you do not need to add roles very frequently. If roles are static, this is always the preferred approach.

### Example: Organization Admin Role

In the model below, we define an `admin` role at the organization level. Admins can edit billing details and create projects.

FGA model · DSL

### Adding Users to Roles

To add users to the admin role, create a tuple like:

```yaml theme={null}
- user: user:anne
  relation: admin
  object: organization:acme
```

### Extending with Additional Roles

If later you need to add a `project_admin` role with permissions to view/edit projects, the model evolves to:

FGA model · DSL

### Pros and Cons

**✅ Advantages:**

* Simple to implement and understand
* Fast evaluation performance
* Clear authorization policies
* No additional tuples needed when adding permissions
* Role permissions are straightforward to change, regardless of scale

**❌ Disadvantages:**

* Roles must be predefined in the model
* Not suitable for user-defined roles

***

## Approach 2: Simple User-Defined Roles

Many applications require the flexibility for end-users to define their own custom roles, in addition to any pre-defined roles. This approach enables organizations to tailor permissions to their specific needs.

### Example: Custom Project Admin Role

With the following model, your application can support both static roles and user-defined roles:

FGA model · DSL

### Setting Up Custom Roles

1. **Define role permissions** by creating tuples that grant the role-specific permissions:

```yaml theme={null}
- user: role:acme-project-admin#assignee
  relation: can_create_project
  object: organization:acme

- user: role:acme-project-admin#assignee
  relation: can_edit_project
  object: organization:acme
```

2. **Assign users to the role**:

```yaml theme={null}
- user: user:anne
  relation: assignee
  object: role:acme-project-admin
```

### Adding New Permissions

When you add new permissions to your model, existing roles don't automatically receive them:

FGA model · DSL

To grant the new permission to existing roles, create additional tuples:

```yaml theme={null}
- user: role:acme-project-admin#assignee
  relation: can_delete_project
  object: organization:acme
```

You do not need to add these tuples when adding the new permission. End-users will add the new permission to their custom roles when they find it appropriate.

### Pros and Cons

**✅ Advantages:**

* Supports user-defined roles
* Flexible permission assignment
* No model changes needed for new role instances

**❌ Disadvantages:**

* More complex than static relations
* Requires additional tuples for role-permission mapping

***

## Approach 3: Role Assignments

The previous approach works well when custom roles are global for the organization. However, if you need roles that can be attached to different object instances with different members for each instance, you need role assignments.

### Example: Project-Specific Admin Roles

Let's say you want a "Project Admin" role where each project can have different admins, but the role permissions remain consistent.

### Step 1: Define the Role and its Permissions

Define a `role` type where you list all the permissions that any role can have:

FGA model · DSL

A "Project Admin" role can have `can_view_project` and `can_edit_project`:

```yaml theme={null}
# Project Admin role has both the can_view_project and can_edit_project assigned
- user: user:*
  relation: can_view_project
  object: role:project-admin

- user: user:*
  relation: can_edit_project
  object: role:project-admin
```

### Step 2: Assign Users to a Role on an Entity

Add a `role_assignment` type to assign users to the role:

FGA model · DSL

### Step 3: Connect to Your Objects

Define an `organization` type with an `admin` role. Then, define a `project` type that links to an `organization` and a `role_assignment`. Note that we are combining a static `admin` role with custom role assignments. We recommend to always use static roles when they are known in advance.

FGA model · DSL

### Setting Up Role Assignments

1. **Create the role assignment instance**:

```yaml theme={null}
- user: user:anne
  relation: assignee
  object: role_assignment:project-admin-openfga

- user: role:project-admin
  relation: role
  object: role_assignment:project-admin-openfga
```

2. **Link the role assignment to the project**:

```yaml theme={null}
- user: role_assignment:project-admin-openfga
  relation: role_assignment
  object: project:openfga
```

3. **Link the project to an organization**:

```yaml theme={null}
- user: organization:acme
  relation: organization
  object: project:openfga
```

### Pros and Cons

**✅ Advantages:**

* Maximum flexibility for instance-specific roles
* Reusable role definitions across different objects
* Fine-grained control over role membership

**❌ Disadvantages:**

* Most complex approach to implement
* Requires careful planning of the role hierarchy
* More tuples needed for setup and maintenance

***

## Choosing the Right Approach

### Decision Tree

1. **Do you need user-defined roles?**
   * No → Use **Relations as Roles**
   * Yes → Continue to step 2

2. **Do roles need different members per object instance?**
   * No → Use **Simple User-Defined Roles**
   * Yes → Use **Role Assignments**

### Performance Considerations

* **Relations as Roles**: Fastest evaluation
* **Simple User-Defined Roles**: Moderate performance impact
* **Role Assignments**: Highest performance impact

## Best Practices

1. **Start simple**: Begin with relations as roles and evolve as needed
2. **Hybrid approach**: Combine static relations for well-known roles with dynamic roles for custom ones
3. **Documentation**: Clearly document your role model for your team
4. **Functional Testing**: [Write tests](https://docs.fga.dev/modeling/testing.md) to verify your model behaves as expected
5. **Performance Testing**: Test performance with realistic data volumes

## Related Sections

Check out these related resources for more information about adopting OpenFGA.

[Custom Roles Step by Step
Follow a detailed walkthrough of implementing custom roles.](https://docs.fga.dev/modeling/basics/custom-roles.md)

[Multi-tenant RBAC Example
See a complete multi-tenant role-based access control implementation.](https://github.com/openfga/sample-stores/blob/main/stores/multitenant-rbac)

[Role Assignments Example
Explore a full role assignments implementation.](https://github.com/openfga/sample-stores/tree/main/stores/role-assignments)