Declare

Declare a class-hash on-chain.

declare("contract_name", opts)

-- @param contract_name - The contract name (string).
string

-- @param opts - Options for the transaction (table).
{
  -- The tx watch interval in milliseconds (or nil to not wait the tx receipt).
  watch_interval = number,
  -- The path to locate contract artifacts. For now, this path is relative
  -- to where you execute `kipt`. Be aware of that.
  artifacts_path = string,
  -- If the class is already declared, no error is returned, the declaration
  -- is skipped and the class hash is returned. The default value is false.
  skip_if_declared = bool,

  -- Any other keys in the table are ignored.
}

-- @return - A table on success, string error otherwise.
{
  -- The transaction hash (only if `skip_if_declared` is false).
  tx_hash = string,
  -- The declared class hash (Sierra class hash).
  class_hash = string,
}

There are two class-hash on Starknet:

Sierra class-hash, which is the hash of the Sierra representation of the program, including the ABI.
Casm class-hash, which is the compiled hash of the program.

By class-hash we regularly speak about the Sierra one. But to declare a contract, we also need the Casm class-hash in order to ensure that the compilation of the Sierra code on-chain is lowered to the expected Casm class-hash.

To ease the process of declaring a new class, you must first use Scarb to compile your contract. Please ensure you've sierra and casm options enabled in your Scarb.toml file.

[[target.starknet-contract]]
# Enable Sierra codegen.
sierra = true
# Enable CASM codegen.
casm = true

This will generated two files (called contracts artifacts):

mycontract.contract_class.json (Sierra)
mycontract.compiled_contract_class.json (Casm)

The two files will be loaded by Kipt. For this, you only need to provide the contract's name and the path to find the artifacts (usually generated in target/dev directory of your scarb package).

Example

local opts = {
  watch_interval = 300,
  artifacts_path = "./target/dev",
}

local decl_res, _ = declare("mycontract", opts)

print("Declare transaction hash:" .. decl_res.tx_hash)
print("Declared class_hash: " .. decl_res.class_hash)

-- If you want to check the error and exit on error:

local decl_res, err = declare("mycontract", opts)

if err then
  print(err)
  -- Use a non-zero value to indicate an error.
  os.exit(1)
end

ℹ️ Note

Providing the path for artifacts and the contract's name, Kipt will search for <contract_name>_contract_class.json or <contract_name>_sierra.json for the Sierra file. And for the Casm file, Kipt will search for <contract_name>_compiled_contract_class.json or <contract_name>_casm.json.

As you can see, in few lines of code you can control the transactions sent on Starknet. And having the class-hash from the declare, you can now easily deploy an instance of the contract.

Kipt Book

Declare

Example