Modular Models

Authorization is application-specific. In an organization with multiple teams building different applications or modules, each team should be able to define and evolve their authorization policies independently.

Modular models allows splitting your authorization model across multiple files and modules, improving upon some of the challenges that may be faced when maintaining an authorization model within a company, such as:

• A model can grow large and difficult to understand.
• As more teams begin to contribute to a model, the ownership boundaries may not be clear and code review processes might not scale.

With modular models, a single model can be split across multiple files in a project and organized in a way that makes sense for the project or teams collaborating on it. For example, modular models allows ownership for reviews to be expressed using a feature like GitHub's, GitLab's or Gitea's code owners.

Key Concepts

fga.mod

The fga.mod file is the project file for modular models. It specifies the schema version for the final combined model and lists the individual files that make up the modular model.

Property	Description
schema	The schema version to be used for the combined model
contents	The individual files that make up the modular model

Modules

OpenFGA modules define the types and relations for a specific application module or service.

Modules are declared using the module keyword in the DSL, and a module can be written across multiple files. A single file cannot have more than one module.

Type Extensions

As teams implement features, they might find that core types they are dependent upon might not contain all the relations they need. However, it might not make sense for these relations to be owned by the owner of that type if they aren't needed across the system.

Modular models solves that problem by allowing individual types to be extended within other modules to to share those relations.

The following are requirements for type extension:

• The extended type must exist
• A single type can only be extended once per file
• The relations added must not already exist, or be part of another type extension

Example

The following example shows how an authorization model for a SaaS compny with a issue tracking and wiki software can implement modular models.

Core

If there is a core set of types owned by a team that manages the overall identity for the company, the following provides the basics: users, organizations and groups that can be used by each product area.

module core

type user

type organization
  relations
    define member: [user]
    define admin: [user]

type group
  relations
    define member: [user]

Issue tracking

The issue tracking software separates out the project- and issue-related types into separate files. Below, we also extend the organization type to add a relation specific to the issue tracking feature: the ability to authorize who can create a project.

module issue-tracker

extend type organization
  relations
    define can_create_project: admin

type project
  relations
    define organization: [organization]
    define viewer: member from organization

module issue-tracker

type ticket
  relations
    define project: [project]
    define owner: [user]

Wiki

The wiki model is managed in one file until it grows. We can also extend the organization type again to add a relation tracking who can create a space.

module wiki

extend type organization
  relations
    define can_create_space: admin


type space
  relations
    define organization: [organization]
    define can_view_pages: member from organization

type page
  relations
    define space: [space]
    define owner: [user]

fga.mod

To deploy this model, create the fga.mod manifest file, set a schema version, and list the individual module files that comprise the model.

schema: '1.2'
contents:
  - core.fga
  - issue-tracker/projects.fga
  - issue-tracker/tickets.fga
  - wiki.fga

Putting it all together

With individual parts of the modular model in place, write the model to OpenFGA and run tests against it. Below is an example of what to run in the CLI:

fga model write --store-id=$FGA_STORE_ID --file fga.mod

This model can now be queried and have tuples written to it, just like a singular file authorization model.

Node.js

await fgaClient.write({
  writes: [
      {"user":"user:anne","relation":"admin","object":"organization:acme"},
      {"user":"organization:acme","relation":"organization","object":"space:acme"},
      {"user":"organization:acme","relation":"organization","object":"project:acme"}
  ],
}, {
  authorization_model_id: "01HVMMBCMGZNT3SED4Z17ECXCA" 
});

Go

options := ClientWriteOptions{
    AuthorizationModelId: PtrString("01HVMMBCMGZNT3SED4Z17ECXCA"),
}

body := ClientWriteRequest{
    Writes: []ClientTupleKey{
        {
             User: "user:anne",
             Relation: "admin",
             Object: "organization:acme",
        },         {
             User: "organization:acme",
             Relation: "organization",
             Object: "space:acme",
        },         {
             User: "organization:acme",
             Relation: "organization",
             Object: "project:acme",
        }, 
    }, 
}

data, err := fgaClient.Write(context.Background()).
    Body(body).
    Options(options).
    Execute()

if err != nil {
    // .. Handle error
}

_ = data // use the response

.NET

var options = new ClientWriteOptions {
    AuthorizationModelId = "01HVMMBCMGZNT3SED4Z17ECXCA",
};
var body = new ClientWriteRequest() {
    Writes = new List<ClientTupleKey>() {
       new() {
                  User = "user:anne",
                  Relation = "admin",
                  Object = "organization:acme"
              },
       new() {
                  User = "organization:acme",
                  Relation = "organization",
                  Object = "space:acme"
              },
       new() {
                  User = "organization:acme",
                  Relation = "organization",
                  Object = "project:acme"
              }
  },
};
var response = await fgaClient.Write(body, options);

Python

options = {
    "authorization_model_id": "01HVMMBCMGZNT3SED4Z17ECXCA"
}
body = ClientWriteRequest(
        writes=[
                ClientTuple(
                    user="user:anne",
                    relation="admin",
                    object="organization:acme",
                ),
                ClientTuple(
                    user="organization:acme",
                    relation="organization",
                    object="space:acme",
                ),
                ClientTuple(
                    user="organization:acme",
                    relation="organization",
                    object="project:acme",
                ),
        ],
)

response = await fga_client.write(body, options)

Java

var options = new ClientWriteOptions()
        .authorizationModelId("01HVMMBCMGZNT3SED4Z17ECXCA");

var body = new ClientWriteRequest()
        .writes(List.of(
                new ClientTupleKey()
                        .user("user:anne")
                        .relation("admin")
                        ._object("organization:acme"),
                new ClientTupleKey()
                        .user("organization:acme")
                        .relation("organization")
                        ._object("space:acme"),
                new ClientTupleKey()
                        .user("organization:acme")
                        .relation("organization")
                        ._object("project:acme")
        ));

var response = fgaClient.write(body, options).get();

CLI

fga tuple write --store-id=${FGA_STORE_ID} --model-id=01HVMMBCMGZNT3SED4Z17ECXCA user:anne admin organization:acme 
fga tuple write --store-id=${FGA_STORE_ID} --model-id=01HVMMBCMGZNT3SED4Z17ECXCA organization:acme organization space:acme 
fga tuple write --store-id=${FGA_STORE_ID} --model-id=01HVMMBCMGZNT3SED4Z17ECXCA organization:acme organization project:acme 

curl

curl -X POST $FGA_API_URL/stores/$FGA_STORE_ID/write \
  -H "Authorization: Bearer $FGA_API_TOKEN" \ # Not needed if service does not require authorization
  -H "content-type: application/json" \
  -d '{"writes": { "tuple_keys" : [{"user":"user:anne","relation":"admin","object":"organization:acme"},{"user":"organization:acme","relation":"organization","object":"space:acme"},{"user":"organization:acme","relation":"organization","object":"project:acme"}] }, "authorization_model_id": "01HVMMBCMGZNT3SED4Z17ECXCA"}'

Node.js

Initialize the SDK

// ApiTokenIssuer, ApiAudience, ClientId and ClientSecret are optional.
// import the SDK
const { OpenFgaClient } = require('@openfga/sdk');

// Initialize the SDK with no auth - see "How to setup SDK client" for more options
const fgaClient = new OpenFgaClient({
  apiUrl: process.env.FGA_API_URL, // required, e.g. https://api.fga.example
  storeId: process.env.FGA_STORE_ID,
  authorizationModelId: process.env.FGA_MODEL_ID, // Optional, can be overridden per request
});

// Run a check
const { allowed } = await fgaClient.check({
    user: 'user:anne',
    relation: 'can_create_space',
    object: 'organization:acme',
  }, {
  authorization_model_id: '01HVMMBCMGZNT3SED4Z17ECXCA',
});

// allowed = true

Go

Initialize the SDK

// ApiTokenIssuer, ApiAudience, ClientId and ClientSecret are optional.
import (
    "os"

    . "github.com/openfga/go-sdk"
    . "github.com/openfga/go-sdk/client"
)

func main() {
    // Initialize the SDK with no auth - see "How to setup SDK client" for more options
    fgaClient, err := NewSdkClient(&ClientConfiguration{
        ApiUrl:               os.Getenv("FGA_API_URL"), // required, e.g. https://api.fga.example
        StoreId:              os.Getenv("FGA_STORE_ID"), // optional, not needed for `CreateStore` and `ListStores`, required before calling for all other methods
        AuthorizationModelId: os.Getenv("FGA_MODEL_ID"),  // Optional, can be overridden per request
    })

    if err != nil {
    // .. Handle error
    }
}

options := ClientCheckOptions{
    AuthorizationModelId: PtrString("01HVMMBCMGZNT3SED4Z17ECXCA"),
}

body := ClientCheckRequest{
    User:     "user:anne",
    Relation: "can_create_space",
    Object:   "organization:acme",
}

data, err := fgaClient.Check(context.Background()).
    Body(body).
    Options(options).
    Execute()

// data = { allowed: true }

.NET

Initialize the SDK

// ApiTokenIssuer, ApiAudience, ClientId and ClientSecret are optional.
// import the SDK
using OpenFga.Sdk.Client;
using OpenFga.Sdk.Client.Model;
using OpenFga.Sdk.Model;
using Environment = System.Environment;

namespace Example;

class Example {
    public static async Task Main() {
        // Initialize the SDK with no auth - see "How to setup SDK client" for more options
        var configuration = new ClientConfiguration() {
          ApiUrl = Environment.GetEnvironmentVariable("FGA_API_URL"), ?? "http://localhost:8080", // required, e.g. https://api.fga.example
          StoreId = Environment.GetEnvironmentVariable("FGA_STORE_ID"), // optional, not needed for `CreateStore` and `ListStores`, required before calling for all other methods
          AuthorizationModelId = Environment.GetEnvironmentVariable("FGA_MODEL_ID"), // Optional, can be overridden per request
        };
        var fgaClient = new OpenFgaClient(configuration);
    }
}

var options = new ClientCheckOptions {
    AuthorizationModelId = "01HVMMBCMGZNT3SED4Z17ECXCA",
};
var body = new ClientCheckRequest {
    User = "user:anne",
    Relation = "can_create_space",
    Object = "organization:acme",
    
};
var response = await fgaClient.Check(body, options);

// response.Allowed = true

Python

Initialize the SDK

# ApiTokenIssuer, ApiAudience, ClientId and ClientSecret are optional.

import asyncio
import os
import json
from openfga_sdk.client import ClientConfiguration, OpenFgaClient

async def main():
    configuration = ClientConfiguration(
        api_url = os.environ.get('FGA_API_URL'), # required, e.g. https://api.fga.example
        store_id = os.environ.get('FGA_STORE_ID'), # optional, not needed for `CreateStore` and `ListStores`, required before calling for all other methods
        authorization_model_id = os.environ.get('FGA_MODEL_ID'), # Optional, can be overridden per request
    )

    # Enter a context with an instance of the OpenFgaClient
    async with OpenFgaClient(configuration) as fga_client:
        api_response = await fga_client.read_authorization_models()
        await fga_client.close()

asyncio.run(main())

options = {
    "authorization_model_id": "01HVMMBCMGZNT3SED4Z17ECXCA"
}
body = ClientCheckRequest(
    user="user:anne",
    relation="can_create_space",
    object="organization:acme",
)

response = await fga_client.check(body, options)

# response.allowed = true

Java

Initialize the SDK

// ApiTokenIssuer, ApiAudience, ClientId and ClientSecret are optional.

import dev.openfga.sdk.api.client.OpenFgaClient;
import dev.openfga.sdk.api.configuration.ClientConfiguration;

public class Example {
  public static void main(String[] args) throws Exception {
      var config = new ClientConfiguration()
              .apiUrl(System.getenv("FGA_API_URL")) // If not specified, will default to "https://localhost:8080"
              .storeId(System.getenv("FGA_STORE_ID")) // Not required when calling createStore() or listStores()
              .authorizationModelId(System.getenv("FGA_AUTHORIZATION_MODEL_ID")); // Optional, can be overridden per request

      var fgaClient = new OpenFgaClient(config);
  }
}

var options = new ClientCheckOptions()
        .authorizationModelId("01HVMMBCMGZNT3SED4Z17ECXCA");

var body = new ClientCheckRequest()
        .user("user:anne")
        .relation("can_create_space")
        ._object("organization:acme");

var response = fgaClient.check(body, options).get();

// response.getAllowed() = true 

CLI

Set FGA_API_URL according to the service you are using (e.g. https://api.fga.example)

Set FGA_API_URL according to the service you are using (e.g. https://api.fga.example)

fga query check --store-id=$FGA_STORE_ID --model-id=01HVMMBCMGZNT3SED4Z17ECXCA user:anne can_create_space organization:acme

# Response: {"allowed":true}

curl

Set FGA_API_URL according to the service you are using (e.g. https://api.fga.example)

Set FGA_API_URL according to the service you are using (e.g. https://api.fga.example)

curl -X POST $FGA_API_URL/stores/$FGA_STORE_ID/check \
  -H "Authorization: Bearer $FGA_API_TOKEN" \ # Not needed if service does not require authorization
  -H "content-type: application/json" \
  -d '{"authorization_model_id": "01HVMMBCMGZNT3SED4Z17ECXCA", "tuple_key":{"user":"user:anne","relation":"can_create_space","object":"organization:acme"}}'

# Response: {"allowed":true}

Pseudocode

check(
  user = "user:anne", // check if the user `user:anne`
  relation = "can_create_space", // has an `can_create_space` relation
  object = "organization:acme", // with the object `organization:acme`
   authorization_id = "01HVMMBCMGZNT3SED4Z17ECXCA"
);

Reply: true

Viewing the model

When using the CLI to view the combined model DSL with fga model get --store-id=$FGA_STORE_ID, the DSL is annotated with comments defining the source module and file for types, relations and conditions.

For example, the organization type shows that the type is defined in the core.fga file as part of the core module, the can_create_project relation is defined in issue-tracker/projects.fga as part of the issuer-tracker module, and the can_create_space relation is defined in the wiki.fga file as part of the wiki module.

type organization # module: core, file: core.fga
  relations
    define admin: [user]
    define member: [user] or admin
    define can_create_project: admin # extended by: module: issue-tracker, file: issue-tracker/projects.fga
    define can_create_space: admin # extended by: module: wiki, file: wiki.fga