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Initialize Configuration

The flow init command creates a new Flow project with a basic flow.json configuration file. This is the first step in setting up any Flow project.

Basic Usage​


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flow init

This command will:

  • Create a new flow.json configuration file
  • Set up default networks (emulator, testnet, mainnet)
  • Create an emulator service account
  • Generate a basic project structure with cadence/ directories

Example Output​


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> flow init
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Configuration initialized
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Service account: 0xf8d6e0586b0a20c7
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Start emulator by running: 'flow emulator'
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Reset configuration using: 'flow init --reset'

Project Structure​

After running flow init, you'll have:


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my-project/
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├── flow.json
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├── emulator-account.pkey
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└── cadence/
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├── contracts/
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├── scripts/
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├── transactions/
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└── tests/

Configuration Only​

If you only want to generate the flow.json file without creating the full project structure, use the --config-only flag:


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flow init --config-only

This is useful when:

  • You already have a project structure
  • You want to add Flow configuration to an existing project
  • You're setting up configuration for a specific environment

Global Configuration​

You can create a global flow.json file that applies to all Flow projects on your system:


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flow init --global

Global configuration locations:

  • macOS/Linux: ~/flow.json
  • Windows: C:\Users\$USER\flow.json

Priority order:

  1. Local flow.json (highest priority)
  2. Global flow.json (lowest priority)

Local configuration files will override global settings for overlapping properties.

Error Handling​

If a flow.json file already exists, you'll see this error:


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❌ Command Error: configuration already exists at: flow.json, if you want to reset configuration use the reset flag

Solutions:

  • Use --reset flag to overwrite existing configuration
  • Delete the existing flow.json file first
  • Initialize in a different directory

Flags​

Reset Configuration​


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flow init --reset

Overwrites existing configuration with a fresh setup.

Configuration Only​


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flow init --config-only

Creates only the flow.json file without project structure.

Global Configuration​


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flow init --global

Creates a global configuration file in your home directory.

Service Account Customization​

Private Key​


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flow init --service-private-key <hex-key>

Specify a custom private key for the service account.

Signature Algorithm​


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flow init --service-sig-algo ECDSA_P256

Options: ECDSA_P256, ECDSA_secp256k1 Default: ECDSA_P256

Hash Algorithm​


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flow init --service-hash-algo SHA3_256

Options: SHA2_256, SHA3_256 Default: SHA3_256

Log Level​


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flow init --log debug

Options: none, error, debug Default: info

Next Steps​

After initializing your configuration:

  1. Review the generated flow.json - Understand the default setup
  2. Add your contracts - Use flow config add contract
  3. Create accounts - Use flow accounts create or flow config add account
  4. Configure deployments - Use flow config add deployment
  5. Start developing - Run flow emulator start
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