The NoFlo Development Environment is an offline-capable, client-side web application that helps users to build and run flow-based programs built with FBP compatible systems such as NoFlo, imgflo and MicroFlo. The NoFlo Development Environment is available under the MIT license.
Flowhub is a hosted and commercially supported version of the NoFlo Development Environment. It is free to use for open source projects, and for private projects if you do not need Github integration.
If you just want to create applications, we recommend that you use this version instead of building your own from source.
FBP systems support
Even though the UI itself is built with NoFlo, it isn't talking directly with NoFlo for running and building graphs. Instead, it is utilizing the FBP Network Protocol which enables it to talk to any compatible FBP system. Currently over 5 different runtimes are known to work.
By implementing the protocol in your runtime, you can program it with NoFlo UI. If you use WebSockets or WebRTC as the transport, you do not need to change anything on NoFlo UI. You can also add support other transports.
Adding new runtime information
One can optionally add component templates, syntax highlighting and a 'get started' link for new runtimes.
- Add a new YAML file with runtime info as
- Include it in ./runtimeinfo/index.coffee
- Commit the changes
- Send a Pull Request, so everyone benefits!
Development of NoFlo UI
Only necessary if you want to hack on NoFlo UI itself. Not neccesary for making apps with FBP.
To be able to work on the NoFlo UI you need:
- A checkout of this repository
- A working Node.js installation
- At least version 3 of the NPM package manager
Go to the checkout folder and run:
$ npm install
You also need the Grunt build tool:
$ sudo npm install -g grunt-cli
This will provide you with all the needed development dependencies. Now you can build a new version by running:
$ grunt build
You have to run this command as an administrator on Windows.
If you prefer, you can also start a watcher process that will do a rebuild whenever one of the files changes:
$ grunt watch
Serve the UI using a webserver, then open the URL it in a web browser. Example:
$ npm start
Once it is built and the server is running you can access the UI at
In addition to this project, the other repository of interest is the the-graph graph editor widget used for editing flows.
Authentication and custom URLs
NoFlo UI is using GitHub for authentication. We have a default application configured to work at
http://localhost:9999. If you want to serve your NoFlo UI from a different URL, you need to register your own OAuth application with them. Make sure to match GitHub's redirect URL policy.
To enable your own OAuth application, set the following environment variables and rebuild NoFlo UI:
$NOFLO_OAUTH_CLIENT_ID: Client ID of your GitHub OAuth application
$NOFLO_OAUTH_CLIENT_REDIRECT: Redirect URL of your GitHub OAuth application
For handling the OAuth Client Secret part of the login process, there are two options:
Built-in OAuth secret
This is the easy option for local NoFlo UI development. Simply build the OAuth client secret into the NoFlo UI app by setting it via the
$NOFLO_OAUTH_CLIENT_SECRET environment variable.
Note: this means anybody with access to this NoFlo UI build will be able to read your client secret. Never do this with a world-accessible URL. It is fine for local-only development builds, though.
You can deploy an instance of the Gatekeeper Node.js app to handle the OAuth token exchange for you. Configure the Gatekeeper location to your NoFlo UI build with
$NOFLO_OAUTH_GATE environment variable.
This is the more secure mechanism, since only the Gatekeeper server needs to know the Client Secret.