Klay for Ruby

A simple library to build and sign Klaytn transactions. Allows separation of key and node management. Sign transactions and handle keys anywhere you can run ruby, broadcast transactions through any node. Sign messages and recover signatures for authentication.

What you get:

Secp256k1 Key-Pairs and Encrypted Klaytn Key-Stores (JSON)
EIP-55 Checksummed Klaytn Addresses
EIP-155 Replay protection with Chain IDs (with presets)
EIP-191 Klaytn Signed Messages (with prefix and type)
EIP-712 Klaytn Signed Type Data
EIP-1559 Klaytn Type-2 Transactions (with priority fee and max gas fee)
EIP-2028 Call-data intrinsic gas cost estimates (plus access lists)
EIP-2718 Klaytn Transaction Envelopes (and types)
EIP-2930 Klaytn Type-1 Transactions (with access lists)
ABI-Encoder and Decoder (including type parser)
RLP-Encoder and Decoder (including sedes)
RPC-Client (IPC/HTTP) for Execution-Layer APIs

1. Installation

Add this line to your application's Gemfile:

gem "klay"

Or install it yourself as:

gem install klay

2. Usage

2.1. Klaytn Keys and Addresses (EIP-55)

Generate a random Secp256k1 key-pair.

key = Klay::Key.new
# => #<Klay::Key:0x00005574a6ba80b8 @private_key=#<Secp256k1::PrivateKey:0x00005574a6b9a0a8 @data=")&\x86P\xB5\x16\xD9]\xFA;\x1F\xF6\xD9\xCF\xE3Vj/\xE2\x81\xC0\x9D\xE9\x05o!q\x82G\x9A\x10Q">, @public_key=#<Secp256k1::PublicKey:0x00005574a6b9bf98>>

Create an password-encrypted Klaytn key-store.

my_key = Klay::Key.new priv: "30137644b564785d01420f8043f043d74dcca64008e57c59f8ce713a0005a54b"
key_store = Klay::Key::Encrypter.perform my_key, "secret-password-1337"
# => "{\"crypto\":{\"cipher\":\"aes-128-ctr\",\"cipherparams\":{\"iv\":\"7e5c0fe1e27f4ea61b0f4427dd63555f\"},\"ciphertext\":\"6353653bba494cdae6bcd510febc980cdc6f7b23cfbdf950d7a909a69625c8fd\",\"kdf\":\"pbkdf2\",\"kdfparams\":{\"c\":262144,\"dklen\":32,\"prf\":\"hmac-sha256\",\"salt\":\"cce96286f3c32267fc91f756365307fe6a4c83b6b2a73c69535f721fa407736c\"},\"mac\":\"3361ffd2b158a1d7bca5a5fd86a251ba3e9d80b602c867a2e0f47023a0e17a57\"},\"id\":\"642ee9fc-72e4-4d0a-902f-247c0b59bfda\",\"version\":3}"
restored_key = Klay::Key::Decrypter.perform key_store, "secret-password-1337"
# => "30137644b564785d01420f8043f043d74dcca64008e57c59f8ce713a0005a54b"

Manage Klaytn address objects adhering to EIP-55 checksum format.

address = Klay::Address.new "0xd496b23d61f88a8c7758fca7560dcfac7b3b01f9"
# => #<Klay::Address:0x00005574a6bd4fc8 @address="0xd496b23d61f88a8c7758fca7560dcfac7b3b01f9">
address.valid?
# => true
address.checksummed # EIP 55
# => "0xD496b23D61F88A8C7758fca7560dCFac7b3b01F9"

See /spec or Documentation for more details about key-pairs, encrypting/decrypting key-stores with a secret, and checksummed addresses.

2.2. Klaytn Signatures (EIP-191, EIP-712)

Manage keypairs to sign messages in EIP-191 (personal_sign) format or typed data in EIP-712 (sign_typed_data) format.

key = Klay::Key.new priv: "268be6f4a68c40f6862b7ac9aed8f701dc25a95ddb9a44d8b1f520b75f440a9a"
# => #<Klay::Key:0x00005574a699adc0 @private_key=#<Secp256k1::PrivateKey:0x00005574a6998200 @data="&\x8B\xE6\xF4\xA6\x8C@\xF6\x86+z\xC9\xAE\xD8\xF7\x01\xDC%\xA9]\xDB\x9AD\xD8\xB1\xF5 \xB7_D\n\x9A">, @public_key=#<Secp256k1::PublicKey:0x00005574a6998160>>
key.public_hex
# => "04b45200621c013a5fbab999ac33b0c836328a04afa0255ffbe6ea0f6fd97e187b02199886d942a9f50f7e279a2bc74c93b2afcbd7255489939f9b36a5eae5e281"
key.address.to_s
# => "0xD496b23D61F88A8C7758fca7560dCFac7b3b01F9"
key.personal_sign "Hello World!"
# => "ac6a59417d8688c8144f01a662384fa691636b48a071d4b7c13902bb87ca472b0bce1d7a758f39a5759ed5e937ce61f50dd1b83158371f8d0faeb9b7d81c194225"

Recover and verify personal signatures respecting EIPs 155, 191, and 712.

address = Klay::Address.new "0xd496b23d61f88a8c7758fca7560dcfac7b3b01f9"
# => #<Klay::Address:0x00005574a6bd4fc8 @address="0xd496b23d61f88a8c7758fca7560dcfac7b3b01f9">
signature = "ac6a59417d8688c8144f01a662384fa691636b48a071d4b7c13902bb87ca472b0bce1d7a758f39a5759ed5e937ce61f50dd1b83158371f8d0faeb9b7d81c19422d"
# => "ac6a59417d8688c8144f01a662384fa691636b48a071d4b7c13902bb87ca472b0bce1d7a758f39a5759ed5e937ce61f50dd1b83158371f8d0faeb9b7d81c19422d"
recovered_key = Klay::Signature.personal_recover "Hello World!", signature, Klay::Chain::GOERLI
# => "04b45200621c013a5fbab999ac33b0c836328a04afa0255ffbe6ea0f6fd97e187b02199886d942a9f50f7e279a2bc74c93b2afcbd7255489939f9b36a5eae5e281"
Klay::Util.public_key_to_address(recovered_key).to_s
# => "0xD496b23D61F88A8C7758fca7560dCFac7b3b01F9"
Klay::Signature.verify "Hello World!", signature, address, Klay::Chain::GOERLI
# => true

See /spec or Documentation for signing typed data as per EIP-712.

2.3. Klaytn Chains (EIP-155)

Manage Klaytn chain IDs for EIP-155 replay protection.

chain_id = Klay::Chain::OPTIMISM
# => 10
v = Klay::Chain.to_v 0, Klay::Chain::OPTIMISM
# => 55
recovery_id = Klay::Chain.to_recovery_id v, Klay::Chain::OPTIMISM
# => 0
chain_id = Klay::Chain.to_chain_id v
# => 10

2.4. Klaytn Transactions (EIP-1559, EIP-2718, EIP-2930)

Create an EIP-1559-conform transaction:

payload = {
  chain_id: Klay::Chain::GOERLI,
  nonce: 5,
  priority_fee: 3 * Klay::Unit::GPEB,
  max_gas_fee: 69 * Klay::Unit::GPEB,
  gas_limit: 230_420,
  to: "0xCaA29806044A08E533963b2e573C1230A2cd9a2d",
  value: 0.069423 * Klay::Unit::KLAY,
}
# => {:chain_id=>5, :nonce=>5, :priority_fee=>0.3e10, :max_gas_fee=>0.69e11, :gas_limit=>230420, :to=>"0xCaA29806044A08E533963b2e573C1230A2cd9a2d", :value=>0.69423e17}
tx = Klay::Tx.new payload
# => #<Klay::Tx::Eip1559:0x0000557e35fc5a68 @access_list=[], @amount=69423000000000000, @chain_id=5, @destination="CaA29806044A08E533963b2e573C1230A2cd9a2d", @gas_limit=230420, @max_fee_per_gas=69000000000, @max_priority_fee_per_gas=3000000000, @payload="", @sender="", @signature_r=0, @signature_s=0, @signature_y_parity=nil, @signer_nonce=5, @type=2>
my_key = Klay::Key.new priv: "30137644b564785d01420f8043f043d74dcca64008e57c59f8ce713a0005a54b"
# => #<Klay::Key:0x0000557e36243178 @private_key=#<Secp256k1::PrivateKey:0x0000557e36242d40 @data="0\x13vD\xB5dx]\x01B\x0F\x80C\xF0C\xD7M\xCC\xA6@\b\xE5|Y\xF8\xCEq:\x00\x05\xA5K">, @public_key=#<Secp256k1::PublicKey:0x0000557e36242cf0>>
tx.sign my_key
# => "cba302c0ebf8d0205a78ae97f560419b407e32e2426f416abc95a9bfc9dac09c"
tx.hex
# => "02f873050584b2d05e00851010b872008303841494caa29806044a08e533963b2e573c1230a2cd9a2d87f6a3d9c63df00080c080a03aa187d10b138d3e0155729adb961cd89e10f988ba2d19d6869770b9e5a23d10a04d40864600136ae214916043c7d63b849c98db757e95c86983a036982816e1af"

This gem also supports access lists and ABI-encoded data payloads. See /spec or Documentation for more details about the various supported transaction types (legacy, type-1, type-2), payload parameters, and how to estimate intrinsic gas costs.

2.5. Klaytn ABI Encoder and Decoder

Encode and decode Klaytn application binary interface data (ABI).

Klay::Util.bin_to_hex Klay::Abi.encode(["string", "address"], ["Hello, Bob!", "0xd496b23d61f88a8c7758fca7560dcfac7b3b01f9"])
# => "0000000000000000000000000000000000000000000000000000000000000040000000000000000000000000d496b23d61f88a8c7758fca7560dcfac7b3b01f9000000000000000000000000000000000000000000000000000000000000000b48656c6c6f2c20426f6221000000000000000000000000000000000000000000"
Klay::Abi.decode(["string", "address"], "0000000000000000000000000000000000000000000000000000000000000040000000000000000000000000d496b23d61f88a8c7758fca7560dcfac7b3b01f9000000000000000000000000000000000000000000000000000000000000000b48656c6c6f2c20426f6221000000000000000000000000000000000000000000")
# => ["Hello, Bob!", "0xd496b23d61f88a8c7758fca7560dcfac7b3b01f9"]

2.6. Klaytn RLP Encoder and Decoder

Serialize and deserialize Klaytn recursive-length prefix data (RLP).

Klay::Util.bin_to_hex Klay::Rlp.encode ["Hello, Bob!", "0xd496b23d61f88a8c7758fca7560dcfac7b3b01f9"]
# => "f78b48656c6c6f2c20426f6221aa307864343936623233643631663838613863373735386663613735363064636661633762336230316639"
Klay::Rlp.decode "f78b48656c6c6f2c20426f6221aa307864343936623233643631663838613863373735386663613735363064636661633762336230316639"
# => ["Hello, Bob!", "0xd496b23d61f88a8c7758fca7560dcfac7b3b01f9"]

Or ;-)

Klay::Rlp.decode "c7c0c1c0c3c0c1c0"
# => [[], [[]], [[], [[]]]]

2.7. Klaytn RPC-Client

Create an IPC- or HTTP-RPC-API client to seamlessly query the chain state, e.g., Infura over HTTPS with access token:

infura = Klay::Client.create "https://mainnet.infura.io/v3/#{access_token}"
# => #<Klay::Client::Http:0x000055d43f3ca460 @gas_limit=21000, @host="mainnet.infura.io", @id=0, @max_fee_per_gas=0.2e11, @max_priority_fee_per_gas=0, @port=443, @ssl=true, @uri=#<URI::HTTPS https://mainnet.infura.io/v3/31b...d93>>
deposit_contract = Klay::Address.new "0x00000000219ab540356cBB839Cbe05303d7705Fa"
# => #<Klay::Address:0x000055d43f381738 @address="0x00000000219ab540356cBB839Cbe05303d7705Fa">
infura.get_balance deposit_contract
# => 9087314000069000000000069

Or set up a local development environment with geth --dev:

cli = Klay::Client.create "/tmp/geth.ipc"
# => #<Klay::Client::Ipc:0x000055d43f51c390 @gas_limit=21000, @id=0, @max_fee_per_gas=0.2e11, @max_priority_fee_per_gas=0, @path="/tmp/geth.ipc">
cli.eth_coinbase
# => {"jsonrpc"=>"2.0", "id"=>1, "result"=>"0x6868074fb21c48dfad0c448fbabd99383a6598e4"}
tx = cli.transfer_and_wait(Klay::Key.new.address, 1337 * Klay::Unit::KLAY)
# => "0x141c6dff40df34fe4fce5a65588d2161dab3e0e977fb8049ff7d79bc901034f7"
cli.eth_get_transaction_by_hash tx
# => {"jsonrpc"=>"2.0", "id"=>8, "result"=> {"blockHash"=>"0x47e742038c75851348dbda87b15fde044d54c442c371f43bea881a44d5589de3", "blockNumber"=>"0x1", "from"=>"0x6868074fb21c48dfad0c448fbabd99383a6598e4", "gas"=>"0x5208", "gasPrice"=>"0x342770c1", "maxFeePerGas"=>"0x77359401", "maxPriorityFeePerGas"=>"0x1", "hash"=>"0x141c6dff40df34fe4fce5a65588d2161dab3e0e977fb8049ff7d79bc901034f7", "input"=>"0x", "nonce"=>"0x0", "to"=>"0x311c61e5dc6123ad016bb7fd687d283c327bcd5f", "transactionIndex"=>"0x0", "value"=>"0x487a9a304539440000", "type"=>"0x2", "accessList"=>[], "chainId"=>"0x539", "v"=>"0x0", "r"=>"0xb42477d69eae65a3a3d91d9cb173e4a45a403fb0a15fa729dbfdc9d13211d7b5", "s"=>"0x4a2f98fc2b61c2d7c907520bc8c6ebe42ea6fe1cb6824f95e4b30e9464395100"}}
cli.get_balance "0x311c61e5dc6123ad016bb7fd687d283c327bcd5f"
# => 1337000000000000000000
cli.get_nonce cli.eth_coinbase["result"]
# => 1

3. Contributing

Pull requests are welcome! To contribute, please consider the following:

Code should be fully documented. Run yard doc and make sure it does not yield any warnings or undocumented sets.
Code should be fully covered by tests. Run rspec to make sure all tests pass. The CI has an integration that will assis you to identify uncovered lines of code and get coverage up to 100%.
Code should be formatted properly. Try to eliminate the most common issues such as trailing white-spaces or duplicate new-lines. Usage of the rufo gem is recommended.
Submit pull requests, questions, or issues to Github: https://github.com/noMacGuffins/klay

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