Awesome Open Source
Awesome Open Source


The Flow Playground is the best way to learn and try Cadence. For newcomers to Flow the Flow Developer Documentation has a guide on how to use the Playground.


How It's Built

We built the Flow Playground as a static website or typical "JAM stack" website because of these properties:

  • Portability. It is easy to move a static website GUI between platforms if desired
  • We want to have the ability to deploy the Playground on peer-to-peer networks like IPFS or DAT
  • Fast build and deploy cycles
  • We want to maximize the amount of potential contributions

What Is the Playground?

We want the Playground to have features that help you build on Flow. We also want to balance functionality with learning. The Playground is a learning tool first and an awesome development tool second, although the two go hand-in-hand.


Read the Contribution Guidelines

Git workflow:

  • Use merge squashing, not commit merging eg. here. Squash merge is your friend.
  • The master branch is the base branch, there is no dedicated development branch



You'll need to have Docker installed to develop.


Clone the repo

git clone [email protected]:onflow/flow-playground.git

Install dependencies

npm install

Rename .env.local to .env

Start the API (Flow Emulator and services)

docker run -e FLOW_DEBUG=true -e FLOW_SESSIONCOOKIESSECURE=false -p 8080:8080

Start the React app

npm run start

✨ The Playground is running on localhost:3000 ✨

If you are using VSCode, you can use this debugging config (works with workspaces)

  "version": "0.2.0",
  "configurations": [
      "name": "Launch",
      "type": "chrome",
      "request": "launch",
      "port": 9229,
      "url": "http://localhost:3000",
      "webRoot": "${workspaceFolder}/src",
      "sourceMaps": true,
      "sourceMapPathOverrides": {
        "webpack:///src/*": "${webRoot}/*",
        "webpack:///./~/*": "${workspaceFolder}/node_modules/*",
        "webpack:///./*": "${webRoot}/*",
        "webpack:///*": "*"
      "trace": true

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