> ## Documentation Index > Fetch the complete documentation index at: https://docs.starknet.io/llms.txt > Use this file to discover all available pages before exploring further. # Transaction fields and hash calculations To review how transaction appear in the Starknet API, see [starknet\_api\_openrpc.json](https://github.com/starkware-libs/starknet-specs/blob/b5c43955b1868b8e19af6d1736178e02ec84e678/api/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](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `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](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `paymaster_data` | `List` | *For future use.*

Currently this value is always empty.

For more information, see [SNIP 8: Transaction V3 Structure](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `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` | Additional information given by the sender, used to validate the transaction. For more information, see [Signature](#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: ```txt theme={null} 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](#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](/learn/protocol/cryptography/#poseidon_hash) 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](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html). ### Transaction fields | Field name | Type | Description | | ------------------------------ | -------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `account_deployment_data` | `List` | *For future use.*

Currently this value is always empty.

For more information, see [SNIP 8: Transaction V3 Structure](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `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](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html). | | `contract_class` | `ContractClass` | The class definition. For more information, see [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html). | | `fee_data_availability_mode` | `FieldElement` | *For future use.*

Currently this value is always `0`.

For more information, see [SNIP 8: Transaction V3 Structure](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `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](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `paymaster_data` | `List` | *For future use.*

Currently this value is always empty.

For more information, see [SNIP 8: Transaction V3 Structure](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `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` | Additional information given by the sender, used to validate the transaction. For more information, see [Signature](#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: ```txt theme={null} 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](#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](/learn/protocol/cryptography/#poseidon_hash) hash. * `class_hash` is the hash of the contract class. See [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html)] 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](/learn/protocol/accounts/#deploying_a_new_account). ### Transaction fields | Field name | Type | Description | | ------------------------------ | -------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `account_deployment_data` | `List` | *For future use.*

Currently this value is always empty.

For more information, see [SNIP 8: Transaction V3 Structure](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `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](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html). | | `compiled_class_hash` | `FieldElement` | The hash of the compiled class. For more information, see [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html). | | `constructor_calldata` | `List` | 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](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html). | | `fee_data_availability_mode` | `FieldElement` | *For future use.*

Currently this value is always `0`.

For more information, see [SNIP 8: Transaction V3 Structure](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `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](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `paymaster_data` | `List` | *For future use.*

Currently this value is always empty.

For more information, see [SNIP 8: Transaction V3 Structure](https://github.com/starknet-io/SNIPs/blob/main/SNIPS/snip-8.md) | | `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` | Additional information given by the sender, used to validate the transaction. For more information, see [Signature](#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: ```txt theme={null} 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](#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](/learn/protocol/cryptography/#poseidon_hash) hash. * `class_hash` is the hash of the contract class hash. See [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html) 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](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html). ## 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](/learn/protocol/cryptography/). ### Chain ID Chain IDs are given as numbers, representing the ASCII encoding of specific constant strings, as illustrated by the following Python snippet: ```python theme={null} 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` | The arguments that are passed to the `validate` and `execute` functions. | | `signature` | `List` | Additional information given by the sender, used to validate the transaction. For more information, see [Signature](#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: ```txt theme={null} 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](#chain-id). * `h` is the [Pedersen](/learn/protocol/cryptography/#pedersen_hash) hash ### `INVOKE` v0 #### Hash calculation The hash of a v0 `INVOKE` transaction is computed as follows: ```txt theme={null} 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](#chain-id). v2 and v3 * `h` is the [Pedersen](/learn/protocol/cryptography/#pedersen_hash) 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](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html). | | `compiled_class_hash` | `FieldElement` | The hash of the compiled class | | `sender_address` | `FieldElement` | The address of the account initiating the transaction. | | `signature` | `List` | Additional information given by the sender, used to validate the transaction. For more information, see [Signature](#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: ```txt theme={null} 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](/learn/protocol/cryptography/#poseidon_hash) * `class_hash` is the hash of the contract class. See [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html) 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` | Additional information given by the sender, used to validate the transaction. For more information, see [Signature](#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: ```txt theme={null} 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](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html) 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](#chain_id). * `h` is the [Pedersen](/learn/protocol/cryptography/#pedersen_hash) 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: ```txt theme={null} 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](/learn/protocol/cryptography/#pedersen_hash) hash * `chain_id` is a constant value that specifies the network to which this transaction is sent. For more information, see [Chain-Id](#chain-id). * `class_hash` is the hash of the contract class. See [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html) 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` | The arguments to the account constructor. | | `contract_address_salt` | `FieldElement` | A random salt that determines the see [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html)\[account address^]. | | `signature` | `List` | Additional information given by the sender, used to validate the transaction. For more information, see [Signature](#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: ```txt theme={null} 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](/learn/protocol/cryptography/#pedersen_hash) hash * `chain_id` is a constant value that specifies the network to which this transaction is sent. For more information, see [\[chain-id\]](#chain-id). * `class_hash` is the hash of the contract class. See [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html) 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: ```txt theme={null} 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](/learn/protocol/cryptography/#pedersen_hash) hash and `sn_keccak` is [Starknet Keccak](/learn/protocol/cryptography/#starknet_keccak). * `chain_id` is a constant value that specifies the network to which this transaction is sent. For more information, see [Chain ID](#chain_id). * `contract_address` is calculated as described see [the Cairo Book](https://book.cairo-lang.org/ch100-01-contracts-classes-and-instances.html).