Start Emulator
The Flow Emulator is a lightweight development tool that mimics the behavior of the real Flow network. It is bundled with the Flow CLI, which makes starting and configuring the emulator straightforward.
Initial Configuration
The emulator requires a configuration file (flow.json). If you don’t already have one, create it using the flow init command:
_10flow init
This initializes a default configuration file that the emulator will use.
Starting the Emulator
To start the emulator with default settings, use the following command:
_10flow emulator
This will start the emulator with the configuration defined in flow.json.
Example Output
When you run the flow emulator command, you will see output similar to the following:
_10INFO[0000] ⚙️ Using service account 0xf8d6e0586b0a20c7 serviceAddress=f8d6e0586b0a20c7 ..._10INFO[0000] 🌱 Starting Flow Emulator_10INFO[0000] 🛠 GRPC server started on 127.0.0.1:3569_10INFO[0000] 📡 HTTP server started on 127.0.0.1:8080
Customizing the Emulator
You can customize the emulator behavior by using flags. Here are some examples:
Change the gRPC and REST API ports:
_10flow emulator --port 9000 --rest-port 9001
Enable persistence of state across restarts:
_10flow emulator --persist
Enable detailed logs for debugging:
_10flow emulator --verbose
For a complete list of available flags, run:
_10flow emulator --help
Learn More
To explore advanced features like snapshots, rollbacks, and debugging, visit the Flow Emulator README.