Fusio is an open source API management platform which helps to build and manage RESTful APIs. We think that there is a huge potential in the API economy. Whether you need an API to expose your business functionality, build micro services, develop SPAs or Mobile-Apps. Because of this we think that Fusio is a great tool to simplify building such APIs. More information on https://www.fusio-project.org/

Fusio covers all important aspects of the API lifecycle so you can concentrate on building the actual business logic of your API.

• Versioning
  It is possible to define different versions of your endpoint. A concrete version can be requested through the Accept header i.e. application/vnd.acme.v1+json
• Documentation
  Fusio generates automatically a documentation of the API endpoints based on the provided schema definitions.
• Validation
  Fusio uses the standard JSONSchema to validate incoming request data
• Authorization
  Fusio uses OAuth2 for API authorization. Each app can be limited to scopes to request only specific endpoints of the API.
• Analytics
  Fusio monitors all API activities and shows them on a dashboard so you always know what is happening with your API.
• Rate limiting
  It is possible to limit the requests to a specific threshold.
• Specification
  Fusio generates different specification formats for the defined API endpoints i.e. OAI (Swagger), RAML.
• User management
  Fusio provides an API where new users can login or register a new account through GitHub, Google, Facebook or through normal email registration.
• Logging
  All errors which occur in your endpoint are logged and are visible at the backend including all information from the request.
• Connection
  Fusio provides an adapter system to connect to external services. By default we provide the HTTP and SQL connection type but there are many other types available i.e. MongoDB, Amqp, Cassandra.
• Migration
  Fusio has a migration system which allows you to change the database schema on deployment.
• Testing
  Fusio provides an api test case wherewith you can test every endpoint response without setting up a local web server.

Basically with Fusio you only have to define the schema (request/response) of your API endpoints and implement the business logic. All other aspects are covered by Fusio.

To give you a first overview, every request which arrives at Fusio goes through the following lifecycle:

Fusio tries to assign the incoming request to a fitting route. The route contains all schema information about the incoming request and outgoing responses. Those schemas are also used at the documentation which is automatically available. If a request schema was provided the incoming request body gets validated after this schema. In case everything is ok the action which is assigned to the route gets executed.

An action represents the code which handles an incoming request and produces a response. Each action can use connections to accomplish this task. A connection uses a library which helps to work with a remote service. I.e. the SQL connection uses the Doctrine DBAL library to work with a database (it returns a Doctrine\DBAL\Connection instance). A connection always returns a fully configured object so you never have to deal with any credentials in an action. Besides that there are already many different actions available which you can use i.e. to create an API based on a database table.

With Fusio we want to remove as many layers as possible so that you can work in your action directly with a specific library. Because of this Fusio has no model or entity system like many other frameworks, instead we recommend to write plain SQL in case you work with a relational database. We think that building API endpoints based on models/entities limits the way how you would design a response. You only need to describe the request and response in the JSON schema format. This schema is then the contract of your API endpoint, how you produce this response technically is secondary. Fusio provides the mentioned connections, which help you to create complete customized responses based on complicated SQL queries, message queue inserts or multiple remote HTTP calls.

Fusio provides two ways to develop an API. The first way is to build API endpoints only through the backend interface by using all available actions. Through this you can solve already many tasks especially through the usage of the v8 action.

The other way is to use the deploy mechanism. Through this you can use normal PHP files to implement your business logic and thus you can use the complete PHP ecosystem. Therefor you need to define a .fusio.yml deploy file which specifies the available routes and actions of the system. This file can be deployed with the following command:

php bin/fusio deploy

The action of each route contains the source which handles the business logic. This can be i.e. a simple php file, php class or a url. More information in the src/ folder. In the following an example action to build an API response from a database:

<?php
/**
 * @var \Fusio\Engine\ConnectorInterface $connector
 * @var \Fusio\Engine\RequestInterface $request
 * @var \Fusio\Engine\Response\FactoryInterface $response
 * @var \Fusio\Engine\ProcessorInterface $processor
 * @var \Psr\Log\LoggerInterface $logger
 * @var \Psr\SimpleCache\CacheInterface $cache
 */

/** @var \Doctrine\DBAL\Connection $connection */
$connection = $connector->getConnection('Default-Connection');

$count   = $connection->fetchColumn('SELECT COUNT(*) FROM app_todo');
$entries = $connection->fetchAll('SELECT * FROM app_todo WHERE status = 1 ORDER BY insertDate DESC LIMIT 16');

return $response->build(200, [], [
    'totalResults' => $count,
    'entry' => $entries,
]);

In the code we get the Default-Connection which we have defined previously in our .fusio.yml deploy file. In this case the connection returns a \Doctrine\DBAL\Connection instance but we have already many adapters to connect to different services. Then we simply fire some queries and return the response.

Fusio provides several apps which work with the internal backend API. These apps can be used to manage and work with the API. This section gives a high level overview what the Fusio system provides and how the application is structured. Lets take a look at the components which are provided by Fusio:

If you install a Fusio system it setups the default API. Through the API it is possible to manage the complete system. Because of that Fusio has some reserved paths which are needed by the system.

• /backend
  Endpoints for the system configuration
• /consumer
  Endpoints for the consumer i.e. register new accounts or create new apps
• /doc
  Endpoints for the documentation
• /authorization
  Endpoints for the consumer to get i.e. information about the user itself and to revoke an obtained access token
• /export
  Endpoints to export the documentation into other formats i.e. swagger

There is also a complete documentation about all internal API endpoints.

The following apps are working with the Fusio API.

The backend app is the app where the administrator can configure the system. The app is located at /fusio/.

The developer app is designed to quickly setup an API program where new developers can register and create/manage their apps. The app is located at /developer/.

The documentation app simply provides an overview of all available endpoints. It is possible to export the API definition into other schema formats like i.e. Swagger. The app is located at /documentation/.

The swagger-ui app renders a documentation based on the OpenAPI specification. The app is located at /swagger-ui/.

It is possible to install Fusio either through composer or manually file download. Place the project into the www directory of the web server.

composer create-project fusio/fusio

https://github.com/apioo/fusio/releases

• Adjust the configuration file
  Open the file .env in the Fusio directory and change the key FUSIO_URL to the domain pointing to the public folder. Also insert the database credentials to the FUSIO_DB_* keys.
• Execute the installation command
  The installation script inserts the Fusio database schema into the provided database. It can be executed with the following command php bin/fusio install.
• Create administrator user
  After the installation is complete you have to create a new administrator account. Therefor you can use the following command php bin/fusio adduser. Choose as account type "Administrator".

You can verify the installation by visiting the FUSIO_URL with a browser. You should see a API response that the installation was successful. The backend is available at /fusio/.

Alternatively it is also possible to setup a Fusio system through docker. This has the advantage that you automatically get a complete running Fusio system without configuration. This is especially great for testing and evaluation. To setup the container you have to checkout the repository and run the following command:

docker-compose up -d

This builds the Fusio system with a predefined backend account. The credentials are taken from the env variables FUSIO_BACKEND_USER, FUSIO_BACKEND_EMAIL and FUSIO_BACKEND_PW in the docker-compose.yml. If you are planing to run the container on the internet you must change these credentials.

The official documentation is available at http://fusio.readthedocs.org/

Today there are many use cases where you need a great documented REST API. In the following we list the most popular choices where Fusio comes in to play.

Exposing an API of your business functionality is a great way to extend your product. You enable customers to integrate it into other applications which gives the possibility to open up for new markets. With Fusio you can build such APIs and integrate them seamlessly into your product. We also see many companies which use the API itself as the core product.

With Fusio you can simply build small micro services which solve a specific task in a complex system.

Javascript frameworks like i.e. AngularJS or EmberJS becoming the standard. With Fusio you can easily build a backend for such applications. So you dont have to build the backend part by yourself.

Almost all mobile apps need some form to interact with a remote service. This is mostly done through REST APIs. With Fusio you can easily build such APIs which then can also be used by other applications.

If you have found bugs or want to make feature requests use the bug tracker on GitHub. For code contributions feel free to send a pull request through GitHub, there we can discuss all details of the changes.