Transaction fields and hash calculations

To review how transaction appear in the Starknet API, see starknet_api_openrpc.json.

INVOKE v3

Transaction fields

Field name	Type	Description
chain_id	FieldElement	The id of the chain to which the transaction is sent.
fee_data_availability_mode	FieldElement	For future use. Currently this value is always 0. For more information, see SNIP 8: Transaction V3 Structure
nonce	FieldElement	The transaction nonce.
nonce_data_availability_mode	FieldElement	For future use. Currently this value is always 0. For more information, see SNIP 8: Transaction V3 Structure
paymaster_data	List<FieldElement>	For future use. Currently this value is always empty. For more information, see SNIP 8: Transaction V3 Structure
resource_bounds	Dict[Resource, ResourceBounds]	Used for enabling the fee market. A dictionary that maps resource type to resource bounds. The existing resources are L1 gas, L1 data gas, and L2 gas. Resource A felt. Possible values are the felt representation of the strings L1_GAS, L1_DATA, or L2_GAS. ResourceBounds A struct containing the following felts: • max_amount: The maximum amount of the resource allowed for usage during the execution. • max_price_per_unit: The maximum price the user is willing to pay for the resource. Prices are denominated in fri, where 1 fri = 10-18 STRK.
signature	List<FieldElement>	Additional information given by the sender, used to validate the transaction. For more information, see Signature.
tip	FieldElement	Used to determine the priority between transactions where the l2gas max_price_per_unit is enough to fit within the block, according to EIP 1559 which Starknet follows since version 0.14.0.
version	FieldElement	The transaction’s version. When the fields that comprise a transaction change, either with the addition of a new field or the removal of an existing field, then the transaction version increases. Transaction version, where n specifies version n transaction. For example: 3 version 3 transaction

Hash calculation

The INVOKE v3 transaction hash is calculated as a Poseidon hash over the given transaction elements, specifically:

invoke_v3_tx_hash = h(
  "invoke",
  version,
  sender_address,
  h(tip, l1_gas_bounds, l2_gas_bounds, l1_data_gas_bounds),
  h(paymaster_data),
  chain_id,
  nonce,
  data_availability_modes,
  h(account_deployment_data),
  h(calldata)
  h(proof_facts)
)

Where:

• invoke is a constant prefix string, encoded in ASCII.

• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see Chain ID.

• proof_facts are included in the hash computation only when present; otherwise, they are omitted.

• l1_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L1\_GAS}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• l2_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L2\_GAS}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• l1_data_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L1\_DATA}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• data_availability_modes is a concatenation of fee_data_availability_mode and nonce_data_availability_mode, as follows:

  $$\underbrace{\texttt{0...0}}_{\text{188 bits}} \, | \, \underbrace{\texttt{nonce\_data\_availability\_mode}}_{\text{32 bits}} \, | \, \underbrace{\texttt{fee\_data\_availability\_mode}}_{\text{32 bits}}$$

• h is the Poseidon hash.

DECLARE v3

The DECLARE transaction introduces new contract classes into the state of Starknet, enabling other contracts to deploy instances of those classes or use them in a library call. For more information, see the Cairo Book.

Transaction fields

Field name	Type	Description
account_deployment_data	List<FieldElement>	For future use. Currently this value is always empty. For more information, see SNIP 8: Transaction V3 Structure
chain_id	FieldElement	The id of the chain to which the transaction is sent.
compiled_class_hash	FieldElement	The hash of the compiled class. For more information, see the Cairo Book.
contract_class	ContractClass	The class definition. For more information, see the Cairo Book.
fee_data_availability_mode	FieldElement	For future use. Currently this value is always 0. For more information, see SNIP 8: Transaction V3 Structure
nonce	FieldElement	The transaction nonce.
nonce_data_availability_mode	FieldElement	For future use. Currently this value is always 0. For more information, see SNIP 8: Transaction V3 Structure
paymaster_data	List<FieldElement>	For future use. Currently this value is always empty. For more information, see SNIP 8: Transaction V3 Structure
resource_bounds	Dict[Resource, ResourceBounds]	Used for enabling the fee market. A dictionary that maps resource type to resource bounds. The existing resources are L1 gas, L1 data gas, and L2 gas. Resource A felt. Possible values are the felt representation of the strings L1_GAS, L1_DATA, or L2_GAS. ResourceBounds A struct containing the following felts: • max_amount: The maximum amount of the resource allowed for usage during the execution. • max_price_per_unit: The maximum price the user is willing to pay for the resource. Prices are denominated in fri, where 1 fri = 10-18 STRK.
sender_address	FieldElement	The address of the account initiating the transaction.
signature	List<FieldElement>	Additional information given by the sender, used to validate the transaction. For more information, see Signature.
tip	FieldElement	For future use. Currently this value is always 0.
version	FieldElement	The transaction’s version. When the fields that comprise a transaction change, either with the addition of a new field or the removal of an existing field, then the transaction version increases. Transaction version, where n specifies version n transaction. For example: 3 version 3 transaction

Hash calculation

The hash of a v3 DECLARE transaction is computed as follows:

declare_v3_tx_hash = h(
  "declare",
  version,
  sender_address,
  h(tip, l1_gas_bounds, l2_gas_bounds, l1_data_gas_bounds),
  h(paymaster_data),
  chain_id,
  nonce,
  data_availability_modes,
  h(account_deployment_data),
  class_hash,
  compiled_class_hash
)

Where:

• declare is a constant prefix string, encoded in ASCII.

• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see Chain ID.

• l1_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L1\_GAS}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• l2_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L2\_GAS}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• l1_data_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L1\_DATA}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• data_availability_modes is a concatenation of fee_data_availability_mode and nonce_data_availability_mode, as follows:

  $$\underbrace{\texttt{0...0}}_{\text{188 bits}} \, | \, \underbrace{\texttt{nonce\_data\_availability\_mode}}_{\text{32 bits}} \, | \, \underbrace{\texttt{fee\_data\_availability\_mode}}_{\text{32 bits}}$$

• h is the Poseidon hash.

• class_hash is the hash of the contract class. See the Cairo Book] for details about how the hash is computed

• compiled_class_hash is the hash of the compiled class generated by the Sierra→Casm compiler that is used in Starknet

DEPLOY_ACCOUNT v3

Since StarkNet v0.10.1 the DEPLOY_ACCOUNT transaction replaces the DEPLOY transaction for deploying account contracts.

To use it, you should first pre-fund your new account address so that you can pay the transaction fee. You can then send the DEPLOY_ACCOUNT transaction.

For more information, see Deploying a new account.

Transaction fields

Field name	Type	Description
account_deployment_data	List<FieldElement>	For future use. Currently this value is always empty. For more information, see SNIP 8: Transaction V3 Structure
chain_id	FieldElement	The id of the chain to which the transaction is sent.
class_hash	FieldElement	The hash of the desired account class. For more information, see the Cairo Book.
compiled_class_hash	FieldElement	The hash of the compiled class. For more information, see the Cairo Book.
constructor_calldata	List<FieldElement>	The arguments to the account constructor.
contract_address_salt	FieldElement	A random salt that determines the account address.
contract_class	ContractClass	The class definition. For more information, see the Cairo Book.
fee_data_availability_mode	FieldElement	For future use. Currently this value is always 0. For more information, see SNIP 8: Transaction V3 Structure
nonce	FieldElement	The transaction nonce.
nonce_data_availability_mode	FieldElement	For future use. Currently this value is always 0. For more information, see SNIP 8: Transaction V3 Structure
paymaster_data	List<FieldElement>	For future use. Currently this value is always empty. For more information, see SNIP 8: Transaction V3 Structure
resource_bounds	Dict[Resource, ResourceBounds]	Used for enabling the fee market. A dictionary that maps resource type to resource bounds. The existing resources are L1 gas, L1 data gas, and L2 gas. Resource A felt. Possible values are the felt representation of the strings L1_GAS, L1_DATA, or L2_GAS. ResourceBounds A struct containing the following felts: • max_amount: The maximum amount of the resource allowed for usage during the execution. • max_price_per_unit: The maximum price the user is willing to pay for the resource. Prices are denominated in fri, where 1 fri = 10-18 STRK.
sender_address	FieldElement	The address of the account initiating the transaction.
signature	List<FieldElement>	Additional information given by the sender, used to validate the transaction. For more information, see Signature.
tip	FieldElement	For future use. Currently this value is always 0.
version	FieldElement	The transaction’s version. When the fields that comprise a transaction change, either with the addition of a new field or the removal of an existing field, then the transaction version increases.Transaction version, where n specifies version n transaction. For example: 3 version 3 transaction

Hash calculation

The hash of a DEPLOY_ACCOUNT transaction is computed as follows:

deploy_account_v3_tx_hash = h(
  "deploy_account",
  version,
  contract_address,
  h(tip, l1_gas_bounds, l2_gas_bounds, l1_data_gas_bounds),
  h(paymaster_data),
  chain_id,
  nonce,
  data_availability_modes,
  h(constructor_calldata),
  class_hash,
  contract_address_salt
)

Where:

• deploy_account is a constant prefix string, encoded in ASCII.

• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see Chain ID.

• l1_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L1\_GAS}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• l2_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L2\_GAS}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• l1_data_gas_bounds is constructed as follows:

  $$\underbrace{\texttt{L1\_DATA}}_{\text{60 bits}} \, | \, \underbrace{\texttt{max\_amount}}_{\text{64 bits}} \, | \, \underbrace{\texttt{max\_price\_per\_unit}}_{\text{128 bits}}$$

• data_availability_modes is a concatenation of fee_data_availability_mode and nonce_data_availability_mode, as follows:

  $$\underbrace{\texttt{0...0}}_{\text{188 bits}} \, | \, \underbrace{\texttt{nonce\_data\_availability\_mode}}_{\text{32 bits}} \, | \, \underbrace{\texttt{fee\_data\_availability\_mode}}_{\text{32 bits}}$$

• h is the Poseidon hash.

• class_hash is the hash of the contract class hash. See the Cairo Book for details about how the hash is computed.

• contract_address is the address of the newly deployed account. For information on how this address is calculated, see the Cairo Book.

Additional information

Signature

While Starknet does not have a specific signature scheme built into the protocol, the Cairo language, in which smart contracts are written, does have an efficient implementation for ECDSA signature with respect to a STARK-friendly curve. For more information, see Cryptography.

Chain ID

Chain IDs are given as numbers, representing the ASCII encoding of specific constant strings, as illustrated by the following Python snippet:

chain_id = int.from_bytes(value, byteorder="big", signed=False)

The following constants are currently used. They correspond to the chain IDs that Starknet currently supports:

• SN_MAIN for Starknet’s main network.
• SN_SEPOLIA for Starknet’s public testnet on Sepolia.

Legacy information

INVOKE v1

Transaction fields

Name	Type	Description
sender_address	FieldElement	The address of the sender of this transaction.
calldata	List<FieldElement>	The arguments that are passed to the validate and execute functions.
signature	List<FieldElement>	Additional information given by the sender, used to validate the transaction. For more information, see Signature.
max_fee	FieldElement	The maximum fee that the sender is willing to pay for the transaction
nonce	FieldElement	The transaction nonce.
version	FieldElement	The transaction’s version. The value is 1. When the fields that comprise a transaction change, either with the addition of a new field or the removal of an existing field, then the transaction version increases.

Hash calculation

The INVOKE v1 transaction hash is calculated as a hash over the given transaction elements, specifically:

invoke_v1_tx_hash = h(
  "invoke",
  version,
  sender_address,
  0,
  h(calldata),
  max_fee,
  chain_id,
  nonce
)

Where:

• invoke is a constant prefix string, encoded in ASCII.
• The placeholder zero is used to align the hash computation for the different types of transactions.
• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see Chain-Id.
• h is the Pedersen hash

INVOKE v0

Hash calculation

The hash of a v0 INVOKE transaction is computed as follows:

invoke_v0_tx_hash = h(
  "invoke",
  version,
  contract_address,
  entry_point_selector,
  h(calldata),
  max_fee,
  chain_id
)

Where:

• invoke is a constant prefix string, encoded in (ASCII).
• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see Chain-Id. v2 and v3
• h is the Pedersen hash

DECLARE v2

Transaction fields

Name	Type	Description
chain_id	FieldElement	The id of the chain to which the transaction is sent.
contract_class	ContractClass	The contract class.
compiled_class_hash	FieldElement	The hash of the compiled class
sender_address	FieldElement	The address of the account initiating the transaction.
signature	List<FieldElement>	Additional information given by the sender, used to validate the transaction. For more information, see Signature.
max_fee	FieldElement	The maximum fee that the sender is willing to pay for the transaction.
nonce	FieldElement	The transaction nonce.
version	FieldElement	The transaction’s version. The value is 2. When the fields that comprise a transaction change, either with the addition of a new field or the removal of an existing field, then the transaction version increases.

Hash calculation

The hash of a v2 DECLARE transaction is computed as follows:

declare_v2_tx_hash = h(
  "declare",
  version,
  sender_address,
  0,
  h(class_hash),
  max_fee,
  chain_id,
  nonce,
  compiled_class_hash
)

Where:

• h is the Poseidon hash function
• class_hash is the hash of the contract class. See the Cairo Book for details about how the hash is computed
• compiled_class_hash is the hash of the compiled class generated by the Sierra→Casm compiler that is used in Starknet

DECLARE v1

Transaction fields

The DECLARE v1 transaction was used to declare Cairo 0 classes.

Name	Type	Description
contract_class	ContractClass	The class object.
sender_address	FieldElement	The address of the account initiating the transaction.
max_fee	FieldElement	The maximum fee that the sender is willing to pay for the transaction.
signature	List<FieldElement>	Additional information given by the sender, used to validate the transaction. For more information, see Signature.
nonce	FieldElement	The transaction nonce.
version	FieldElement	The transaction’s version. Possible values are 1 or 0. When the fields that comprise a transaction change, either with the addition of a new field or the removal of an existing field, then the transaction version increases.

Hash calculation

The hash of a v1 DECLARE transaction is computed as follows:

declare_v1_tx_hash = h(
  "declare",
  version,
  sender_address,
  0,
  h(class_hash),
  max_fee,
  chain_id,
  nonce
)

Where:

• declare is a constant prefix string, encoded in ASCII.
• class_hash is the hash of the contract class. See the Cairo Book for details about how the hash is computed.
• The placeholder zero is used to align the hash computation for the different types of transactions.
• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see Chain ID.
• h is the Pedersen hash

DECLARE v0

Hash calculation

The DECLARE v0 transaction used to declare Cairo 0 classes.

The hash of a v0 DECLARE transaction is computed as follows:

declare_v0_tx_hash = h(
  "declare",
  version,
  sender_address,
  0,
  h(),
  max_fee,
  chain_id,
  class_hash
)

Where:

• declare is a constant prefix string, encoded in ASCII.
• The placeholder zeros are used to align the hash computation for the different types of transactions.
• h is the Pedersen hash
• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see Chain-Id.
• class_hash is the hash of the contract class. See the Cairo Book for details about how the hash is computed.

DEPLOY_ACCOUNT v1

Transaction fields

Name	Type	Description
class_hash	FieldElement	The hash of the desired account class.
constructor_calldata	List<FieldElement>	The arguments to the account constructor.
contract_address_salt	FieldElement	A random salt that determines the see the Cairo Book[account address^].
signature	List<FieldElement>	Additional information given by the sender, used to validate the transaction. For more information, see Signature.
max_fee	FieldElement	The maximum fee that the sender is willing to pay for the transaction
nonce	FieldElement	The transaction nonce.
version	FieldElement	The transaction’s version. The value is 1.

Hash calculation

The hash of a DEPLOY_ACCOUNT transaction is computed as follows:

deploy_account_v1_tx_hash = h(
  "deploy_account",
  version,
  contract_address,
  0,
  h(class_hash, contract_address_salt, constructor_calldata),
  max_fee,
  chain_id,
  nonce
)

Where:

• deploy_account is a constant prefix string, encoded in ASCII.
• The placeholder zero is used to align the hash computation for the different types of transactions.
• h is the Pedersen hash
• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see [chain-id].
• class_hash is the hash of the contract class. See the Cairo Book for details about how the hash is computed.

DEPLOY v0

Hash calculation

If you need to retrieve the hash of an existing DEPLOY transaction, you can use this information to calculate the hash of the transaction.

Before you can calculate the transaction hash, get the deployed contract address. The DEPLOY transaction’s hash is calculated as shown in the following pseudo code:

deploy_tx_hash = h(
  "deploy",
  version,
  contract_address,
  sn_keccak("constructor"),
  h constructor_calldata),
  0,
  chain_id
)

Where:

• The placeholder zero is used to align the hash computation for the different types of transactions.
• deploy and constructor are constant strings encoded in ASCII.
• h is the Pedersen hash and sn_keccak is Starknet Keccak.
• chain_id is a constant value that specifies the network to which this transaction is sent. For more information, see Chain ID.
• contract_address is calculated as described see the Cairo Book.