The init command creates a new blockchain with a genesis block and generates authority keypairs for block production.
Basic Usage Quick Start Initialize a blockchain with default settings:
cargo run --release -- init
Output: Initializing minichain... ✓ Created data directory Generating authorities... Authority 1: 0xf4a5e8c2b9d7f3a1... ✓ Created genesis block Hash: 0x7d9f2a5c8e4b1f3a... Height: 0 ✓ Saved authority 1 keypair to: data/keys/authority_0.json ✓ Saved config to: data/config.json Chain initialized successfully! Next steps: • Use minichain account new to create accounts • Use minichain tx send to send transactions • Use minichain block list to explore blocks
Options Data Directory Specifies where to store blockchain data. Defaults to ./data.
Example: minichain init --data-dir ./my-blockchain
This creates the following structure:
my-blockchain/ ├── keys/ │ └── authority_0.json ├── config.json └── sled/ # Database files
Number of Authorities Generates the specified number of authority keypairs for block production. Defaults to 1.
Example: minichain init --authorities 3
Output: Generating authorities... Authority 1: 0xf4a5e8c2b9d7f3a1... Authority 2: 0x3d8e9f2a6b4c1e7f... Authority 3: 0x8a2c5d9e1f4b7a3c... ✓ Saved authority 1 keypair to: data/keys/authority_0.json ✓ Saved authority 2 keypair to: data/keys/authority_1.json ✓ Saved authority 3 keypair to: data/keys/authority_2.json
With multiple authorities, block production rotates in round-robin order based on block height.
Block Time Sets the target block production time in seconds. Defaults to 5.
Example: minichain init --block-time 10
This is a target time for consensus validation. It doesn’t enforce automatic block production—authorities must manually produce blocks using minichain block produce.
Force Reinitialization Deletes existing blockchain data and reinitializes from scratch.
Example: Output: Initializing minichain... ✓ Removed existing data directory ✓ Created data directory ...
This permanently deletes all blockchain data, including accounts, transactions, and blocks. Use with caution!
Complete Example Initialize a 3-authority chain with custom settings:
minichain init \ --data-dir ./testnet \ --authorities 3 \ --block-time 2
Genesis Block The init command creates a genesis block (block 0) with these properties:
Height: 0Previous Hash: All zeros (0x0000000000000000...)Timestamp: Current Unix timestampTransactions: EmptyAuthority: First generated authority signs the block
The genesis block is cryptographically signed and stored in the database.
Generated Files Authority Keypairs Authority keypairs are saved as JSON files in data/keys/:
{ "address" : "0xf4a5e8c2b9d7f3a1e6b8c4d9f2a5e8c1" , "public_key" : "e8c2b9d7f3a1e6b8c4d9f2a5e8c1f4a5..." , "private_key" : "a1e6b8c4d9f2a5e8c1f4a5e8c2b9d7f3..." }
Authority private keys grant permission to produce blocks. Store them securely and never commit to version control.
Configuration File The blockchain configuration is saved to data/config.json:
{ "authorities" : [ "0xf4a5e8c2b9d7f3a1e6b8c4d9f2a5e8c1" , "0x3d8e9f2a6b4c1e7f8a2c5d9e1f4b7a3c" ], "block_time" : 5 , "max_block_size" : 1000 }
This file is read by other commands to understand the blockchain configuration.
Proof of Authority Consensus Minichain uses Proof of Authority (PoA) consensus:
Round-robin scheduling: Authority selection is deterministic based on block heightFormula: authority_index = height % authority_countSignature validation: Each block must be signed by the correct authority
Example with 3 authorities:
Block 0: Authority 0
Block 1: Authority 1
Block 2: Authority 2
Block 3: Authority 0 (wraps around)
Block 4: Authority 1
…
See the Consensus documentation for more details on PoA. Common Errors Already Initialized $ minichain init Error: Chain already initialized. Use --force to reinitialize.
Solution: Add --force flag or use a different data directory.Permission Denied $ minichain init --data-dir /root/chain Error: Failed to create data directory: /root/chain
Solution: Use a directory where you have write permissions.Next Steps After initialization:
Create user accounts with minichain account newFund accounts using minichain account mint (authority only)Start transacting with minichain tx sendProduce blocks using minichain block produce
Account Management Create and manage accounts
Block Production Learn how to produce blocks