Transaction

typedef struct cardano_transaction_t cardano_transaction_t

A transaction is a record of value transfer between two or more addresses on the network.

It represents a request to modify the state of the blockchain, by transferring a certain amount of ADA or a native asset from one address to another. Each transaction includes inputs and outputs, where the inputs represent the addresses that are sending ADA or the native asset, and the outputs represent the addresses that are receiving ADA or the native asset.

To ensure the security and integrity of the Cardano blockchain, each transaction is cryptographically signed using the private key of the sender’s address, which proves that the sender has authorized the transaction.

Additionally, each transaction on the Cardano blockchain can also carry metadata, which can be used to include additional information about the transaction, such as a description or a reference to a specific product or service.

cardano_error_t cardano_transaction_new(cardano_transaction_body_t *body, cardano_witness_set_t *witness_set, cardano_auxiliary_data_t *auxiliary_data, cardano_transaction_t **transaction)

Creates and initializes a new Cardano transaction.

This function allocates and initializes a new instance of a cardano_transaction_t object, which represents a Cardano transaction consisting of a transaction body, witness set, and optional auxiliary data.

Usage Example: 

cardano_transaction_body_t* body = ...; // Assume body is initialized
cardano_witness_set_t* witness_set = ...; // Assume witness set is initialized
cardano_auxiliary_data_t* auxiliary_data = ...; // Optional: can be NULL if no auxiliary data is present
cardano_transaction_t* transaction = NULL;

cardano_error_t result = cardano_transaction_new(body, witness_set, auxiliary_data, &transaction);

if (result == CARDANO_SUCCESS)
{
  // Use the transaction

  // Once done, ensure to clean up and release the transaction
  cardano_transaction_unref(&transaction);
}
else
{
  printf("Failed to create transaction: %s\n", cardano_error_to_string(result));
}

Parameters:
cardano_transaction_body_t *body

[in] A pointer to an initialized cardano_transaction_body_t object that represents the transaction body. This parameter is required and must not be NULL.

cardano_witness_set_t *witness_set

[in] A pointer to an initialized cardano_witness_set_t object that contains the witness data for the transaction. This parameter is required and must not be NULL.

cardano_auxiliary_data_t *auxiliary_data

[in] An optional pointer to a cardano_auxiliary_data_t object representing any auxiliary data associated with the transaction. This parameter can be NULL if no auxiliary data is provided.

cardano_transaction_t **transaction

[out] On successful creation, this will point to a newly created cardano_transaction_t object. The caller is responsible for managing the lifecycle of this object. Specifically, once the transaction is no longer needed, the caller must release it by calling cardano_transaction_unref.

Returns:

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the transaction was successfully created, or an appropriate error code indicating the failure reason, such as CARDANO_ERROR_POINTER_IS_NULL if required inputs (body or witness_set) are NULL.

cardano_error_t cardano_transaction_from_cbor(cardano_cbor_reader_t *reader, cardano_transaction_t **transaction)

Creates a cardano_transaction_t from a CBOR reader.

This function parses CBOR data using a provided cardano_cbor_reader_t and constructs a cardano_transaction_t object. It assumes that the CBOR reader is set up correctly and that the CBOR data corresponds to the structure expected for a transaction.

Usage Example: 

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_transaction_t* transaction = NULL;

cardano_error_t result = cardano_transaction_from_cbor(reader, &transaction);

if (result == CARDANO_SUCCESS)
{
  // Use the transaction

  // Once done, ensure to clean up and release the transaction
  cardano_transaction_unref(&transaction);
}
else
{
  const char* error = cardano_cbor_reader_get_last_error(reader);
  printf("Failed to decode transaction: %s\n", error);
}

cardano_cbor_reader_unref(&reader); // Cleanup the CBOR reader

Remark

In Cardano, transactions are encoded in CBOR, but CBOR allows multiple valid ways to encode the same data. The Cardano blockchain does not enforce a canonical transaction representation, meaning that if you decode a transaction from CBOR and then re-encode it, the resulting encoding could be different. This would change the transaction hash and invalidate any existing signatures. To prevent this, when a transaction object is created using cardano_transaction_from_cbor, it caches the original CBOR representation internally. When cardano_transaction_to_cbor is called, it will output the cached CBOR. If the cached CBOR representation is not needed, the client can call cardano_transaction_clear_cbor_cache after the object has been created.

Note

If the function fails, the last error can be retrieved by calling cardano_cbor_reader_get_last_error with the reader. The caller is responsible for freeing the created cardano_transaction_t object by calling cardano_transaction_unref when it is no longer needed.

Parameters:
cardano_cbor_reader_t *reader

[in] A pointer to an initialized cardano_cbor_reader_t that is ready to read the CBOR-encoded data.

cardano_transaction_t **transaction

[out] A pointer to a pointer of cardano_transaction_t that will be set to the address of the newly created transaction object upon successful decoding.

Returns:

A cardano_error_t value indicating the outcome of the operation. Returns CARDANO_SUCCESS if the transaction were successfully created, or an appropriate error code if an error occurred.

cardano_error_t cardano_transaction_to_cbor(const cardano_transaction_t *transaction, cardano_cbor_writer_t *writer)

Serializes transaction into CBOR format using a CBOR writer.

This function serializes the given cardano_transaction_t object using a cardano_cbor_writer_t.

Usage Example: 

cardano_transaction_t* transaction = ...;
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

if (writer)
{
  cardano_error_t result = cardano_transaction_to_cbor(transaction, writer);

  if (result == CARDANO_SUCCESS)
  {
    // Use the writer's buffer containing the serialized data
  }
  else
  {
    const char* error_message = cardano_cbor_writer_get_last_error(writer);
    printf("Serialization failed: %s\n", error_message);
  }

  cardano_cbor_writer_unref(&writer);
}

cardano_transaction_unref(&transaction);

Remark

In Cardano, transactions are encoded in CBOR, but CBOR allows multiple valid ways to encode the same data. The Cardano blockchain does not enforce a canonical transaction representation, meaning that if you decode a transaction from CBOR and then re-encode it, the resulting encoding could be different. This would change the transaction hash and invalidate any existing signatures. To prevent this, when a transaction object is created using cardano_transaction_from_cbor, it caches the original CBOR representation internally. When cardano_transaction_to_cbor is called, it will output the cached CBOR. If the cached CBOR representation is not needed, the client can call cardano_transaction_clear_cbor_cache after the object has been created.

Parameters:
const cardano_transaction_t *transaction

[in] A constant pointer to the cardano_transaction_t object that is to be serialized.

cardano_cbor_writer_t *writer

[out] A pointer to a cardano_cbor_writer_t where the CBOR serialized data will be written. The writer must already be initialized and ready to accept the data.

Returns:

Returns CARDANO_SUCCESS if the serialization is successful. If the transaction or writer is NULL, returns CARDANO_ERROR_POINTER_IS_NULL.

cardano_error_t cardano_transaction_to_cip116_json(const cardano_transaction_t *tx, cardano_json_writer_t *writer)

Serializes a transaction to CIP-116 JSON.

The function writes the full JSON object, including the surrounding braces. Keys are written in the order: “body”, “is_valid”, “witness_set”, “auxiliary_data” (if present).

Parameters:
const cardano_transaction_t *tx

[in] Pointer to a valid cardano_transaction_t.

cardano_json_writer_t *writer

[in] Pointer to a valid cardano_json_writer_t.

Returns:

CARDANO_SUCCESS On success.

Returns:

CARDANO_ERROR_POINTER_IS_NULL If tx or writer is NULL.

Returns:

Other Any error propagated from nested serialization calls.

cardano_transaction_body_t *cardano_transaction_get_body(cardano_transaction_t *transaction)

Retrieves the transaction body from a transaction object.

This function extracts the transaction body (cardano_transaction_body_t) from a given cardano_transaction_t object. The transaction body contains the essential elements of the transaction, such as inputs, outputs, fees, and more.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is already initialized
cardano_transaction_body_t* body = cardano_transaction_get_body(transaction);

if (body != NULL)
{
  // Use the transaction body

  // Clean up the body reference when done
  cardano_transaction_body_unref(&body);
}
else
{
  printf("Failed to retrieve transaction body.\n");
}

Parameters:
cardano_transaction_t *transaction

[in] A pointer to an initialized cardano_transaction_t object.

Returns:

A pointer to the cardano_transaction_body_t object representing the body of the transaction. The returned body is a new reference, and the caller is responsible for managing its lifecycle. Once the body is no longer needed, the caller must release it by calling cardano_transaction_body_unref. If the input transaction pointer is NULL, this function returns NULL.

cardano_error_t cardano_transaction_set_body(cardano_transaction_t *transaction, cardano_transaction_body_t *body)

Sets the transaction body for a transaction.

This function allows replacing or setting the transaction body for a given cardano_transaction_t object. The transaction body encapsulates inputs, outputs, fees, and other transaction-level data.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is already initialized
cardano_transaction_body_t* new_body = ...; // Assume new_body is already initialized

cardano_error_t result = cardano_transaction_set_body(transaction, new_body);
if (result == CARDANO_SUCCESS)
{
  printf("Transaction body set successfully.\n");
}
else
{
  printf("Failed to set transaction body.\n");
}

Note

The reference count of the transaction body will be incremented by this function, so the caller retains ownership of the body object and is responsible for releasing it when it is no longer needed.

Parameters:
cardano_transaction_t *transaction

[inout] A pointer to an initialized cardano_transaction_t object in which the body will be set.

cardano_transaction_body_t *body

[in] A pointer to an initialized cardano_transaction_body_t object representing the new transaction body.

Returns:

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the body was successfully set, or an appropriate error code such as CARDANO_ERROR_POINTER_IS_NULL if the transaction or body pointers are NULL.

cardano_witness_set_t *cardano_transaction_get_witness_set(cardano_transaction_t *transaction)

Retrieves the witness set associated with a transaction.

This function returns the witness set from the given cardano_transaction_t object. The witness set contains cryptographic signatures, public keys, and other necessary information required to verify the transaction.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume initialized
cardano_witness_set_t* witness_set = cardano_transaction_get_witness_set(transaction);

if (witness_set != NULL)
{
  // Use the witness set

  // Cleanup the witness set once done
  cardano_witness_set_unref(&witness_set);
}

Note

The returned witness set is a “strong reference” and must be unref’d by the caller once it’s no longer needed.

Parameters:
cardano_transaction_t *transaction

[in] A pointer to an initialized cardano_transaction_t object.

Returns:

A pointer to a cardano_witness_set_t object representing the witness set. This function returns a new reference to the witness set, and the caller is responsible for managing its lifecycle by calling cardano_witness_set_unref when it is no longer needed.

cardano_error_t cardano_transaction_set_witness_set(cardano_transaction_t *transaction, cardano_witness_set_t *witness_set)

Sets the witness set for a transaction.

This function assigns a witness set to the specified cardano_transaction_t object. A witness set contains the cryptographic signatures and other witness data needed to validate the transaction on the Cardano blockchain.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is already initialized
cardano_witness_set_t* witness_set = ...; // Assume witness_set is already initialized

cardano_error_t result = cardano_transaction_set_witness_set(transaction, witness_set);
if (result == CARDANO_SUCCESS)
{
  printf("Witness set successfully added to the transaction.\n");
}
else
{
  printf("Failed to set witness set: %s\n", cardano_error_to_string(result));
}

// Clean up when no longer needed
cardano_witness_set_unref(&witness_set);
cardano_transaction_unref(&transaction);

Note

This function increases the reference count of the witness_set object, meaning the caller retains ownership of the witness set and must release it by calling cardano_witness_set_unref when it is no longer needed.

Parameters:
cardano_transaction_t *transaction

[inout] A pointer to an initialized cardano_transaction_t object to which the witness set will be added. This parameter must not be NULL.

cardano_witness_set_t *witness_set

[in] A pointer to an initialized cardano_witness_set_t object representing the witness data. This parameter must not be NULL.

Returns:

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the witness set was successfully added to the transaction, or an appropriate error code if any of the input pointers (transaction or witness_set) is NULL, such as CARDANO_ERROR_POINTER_IS_NULL.

cardano_auxiliary_data_t *cardano_transaction_get_auxiliary_data(cardano_transaction_t *transaction)

Retrieves the auxiliary data from a transaction.

This function fetches the auxiliary data associated with a given cardano_transaction_t object.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is already initialized
cardano_auxiliary_data_t* aux_data = cardano_transaction_get_auxiliary_data(transaction);

if (aux_data != NULL)
{
  // Process the auxiliary data
  cardano_auxiliary_data_unref(&aux_data); // Clean up when done
}
else
{
  printf("No auxiliary data found in the transaction.\n");
}

// Clean up the transaction when no longer needed
cardano_transaction_unref(&transaction);

Note

Auxiliary data is optional in a transaction and may not always be present. Therefore, it is important to check the return value for NULL before dereferencing it.

Parameters:
cardano_transaction_t *transaction

[in] A pointer to an initialized cardano_transaction_t object. This parameter must not be NULL.

Returns:

A pointer to a cardano_auxiliary_data_t object representing the auxiliary data in the transaction. If the transaction does not contain auxiliary data, the function will return NULL. The returned object is a new reference, and the caller is responsible for managing its lifecycle. Specifically, the caller must release the object by calling cardano_auxiliary_data_unref when it is no longer needed.

cardano_error_t cardano_transaction_set_auxiliary_data(cardano_transaction_t *transaction, cardano_auxiliary_data_t *auxiliary_data)

Sets the auxiliary data for a transaction.

This function assigns auxiliary data to the specified cardano_transaction_t object. Auxiliary data typically contains additional metadata or governance-related information, such as voting procedures or proposals.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is initialized
cardano_auxiliary_data_t* aux_data = ...; // Assume auxiliary_data is initialized

cardano_error_t result = cardano_transaction_set_auxiliary_data(transaction, aux_data);
if (result == CARDANO_SUCCESS)
{
  printf("Auxiliary data successfully set for the transaction.\n");
}
else
{
  printf("Failed to set auxiliary data: %s\n", cardano_error_to_string(result));
}

// Clean up resources
cardano_auxiliary_data_unref(&aux_data);
cardano_transaction_unref(&transaction);

Remark

Auxiliary data is optional in Cardano transactions, but it can carry critical metadata for on-chain governance, like voting and proposals.

Note

This function increases the reference count of the auxiliary_data object. The caller retains ownership of the auxiliary data and must release it by calling cardano_auxiliary_data_unref when it is no longer needed.

Parameters:
cardano_transaction_t *transaction

[inout] A pointer to an initialized cardano_transaction_t object where the auxiliary data will be set. This parameter must not be NULL.

cardano_auxiliary_data_t *auxiliary_data

[in] A pointer to an initialized cardano_auxiliary_data_t object representing the auxiliary data to be included in the transaction. This parameter can be NULL to unset the auxiliary data in the transaction.

Returns:

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the auxiliary data was successfully set. Returns CARDANO_ERROR_POINTER_IS_NULL if either the transaction or auxiliary_data is NULL.

bool cardano_transaction_get_is_valid(cardano_transaction_t *transaction)

Gets whether the transaction is expected to fail Plutus script validation.

This function retrieves the validity flag of a cardano_transaction_t object, indicating whether the transaction is expected to pass or fail Plutus script validation. A transaction with this flag set to false is expected to fail validation, but it can still be submitted to the blockchain.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is already initialized
bool is_valid = cardano_transaction_get_is_valid(transaction);

if (is_valid)
{
  printf("Transaction is expected to pass Plutus script validation.\n");
}
else
{
  printf("Transaction is expected to fail Plutus script validation.\n");
}

// Clean up resources
cardano_transaction_unref(&transaction);

Note

Even if a transaction is expected to fail validation (i.e., the flag is false), it can still be submitted to the blockchain.

Parameters:
cardano_transaction_t *transaction

[in] A pointer to an initialized cardano_transaction_t object. This parameter must not be NULL.

Returns:

false if the transaction is expected to fail Plutus script validation; otherwise, true.

cardano_error_t cardano_transaction_set_is_valid(cardano_transaction_t *transaction, bool is_valid)

Sets whether the transaction is expected to pass or fail Plutus script validation.

This function assigns a validity flag to the specified cardano_transaction_t object, indicating whether the transaction is expected to pass or fail Plutus script validation. Even if this flag is set to false (indicating expected failure), the transaction can still be submitted to the blockchain.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is initialized
bool expected_to_pass = false; // Set the transaction to expected failure

cardano_error_t result = cardano_transaction_set_is_valid(transaction, expected_to_pass);
if (result == CARDANO_SUCCESS)
{
  printf("Transaction validity flag successfully set.\n");
}
else
{
  printf("Failed to set transaction validity: %s\n", cardano_error_to_string(result));
}

// Clean up resources
cardano_transaction_unref(&transaction);

Note

A transaction with the validity flag set to false (indicating expected failure) can still be submitted to the blockchain.

Parameters:
cardano_transaction_t *transaction

[inout] A pointer to an initialized cardano_transaction_t object for which the validity flag will be set. This parameter must not be NULL.

bool is_valid

[in] A boolean flag indicating the transaction’s expected validation status. If set to true, the transaction is expected to pass validation; if set to false, it is expected to fail validation.

Returns:

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the validity flag was successfully set, or CARDANO_ERROR_POINTER_IS_NULL if the transaction pointer is NULL.

cardano_blake2b_hash_t *cardano_transaction_get_id(cardano_transaction_t *transaction)

Retrieves the transaction ID (hash) from a transaction.

This function computes and returns the unique identifier (ID) for the specified cardano_transaction_t object. The transaction ID is the Blake2b hash of the transaction body and is used to reference the transaction within the Cardano blockchain.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is already initialized
cardano_blake2b_hash_t* tx_id = cardano_transaction_get_id(transaction);

if (tx_id != NULL)
{
  // Use the transaction ID for reference or verification

  // Clean up when done
  cardano_blake2b_hash_unref(&tx_id);
}
else
{
  printf("Failed to retrieve the transaction ID.\n");
}

// Clean up resources
cardano_transaction_unref(&transaction);

Note

The transaction ID is the primary reference used in Cardano to identify and track transactions on the blockchain.

Parameters:
cardano_transaction_t *transaction

[in] A pointer to an initialized cardano_transaction_t object. This parameter must not be NULL.

Returns:

A pointer to a cardano_blake2b_hash_t object representing the transaction ID (hash). The returned object is a new reference, and the caller is responsible for managing its lifecycle. Specifically, the caller must release the object by calling cardano_blake2b_hash_unref when it is no longer needed. If the transaction is NULL, the function returns NULL.

void cardano_transaction_clear_cbor_cache(cardano_transaction_t *transaction)

Clears the cached CBOR representation from a transaction.

This function removes the internally cached CBOR data from a cardano_transaction_t object. It is useful when you have modified the transaction after it was created from CBOR using cardano_transaction_from_cbor and you want to ensure that the next serialization reflects the current state of the transaction, rather than using the original cached CBOR.

Usage Example: 

// Assume transaction was created using cardano_transaction_from_cbor
cardano_transaction_t* transaction = ...;

// Modify the transaction as needed

if (result != CARDANO_SUCCESS)
{
  printf("Failed to set new fee: %s\n", cardano_error_to_string(result));
}

// Clear the CBOR cache to ensure serialization uses the updated transaction
cardano_transaction_clear_cbor_cache(transaction);

// Serialize the transaction to CBOR
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

result = cardano_transaction_to_cbor(transaction, writer);

if (result == CARDANO_SUCCESS)
{
  // Process the CBOR data as needed
}
else
{
  const char* error_message = cardano_cbor_writer_get_last_error(writer);
  printf("Serialization failed: %s\n", error_message);
}

// Clean up resources
cardano_cbor_writer_unref(&writer);
cardano_transaction_unref(&transaction);

Note

After calling this function, subsequent calls to cardano_transaction_to_cbor will serialize the transaction using the standard encoding as defined in CIP-21, rather than reusing the original cached CBOR.

Warning

Clearing the CBOR cache may change the binary representation of the transaction when serialized, which can alter the transaction hash and invalidate any existing signatures. Use this function with caution, especially if the transaction has already been signed or if preserving the exact CBOR encoding is important for your application.

Parameters:
cardano_transaction_t *transaction

[inout] A pointer to an initialized cardano_transaction_t object from which the CBOR cache will be cleared.

cardano_error_t cardano_transaction_apply_vkey_witnesses(cardano_transaction_t *transaction, cardano_vkey_witness_set_t *new_vkeys)

Applies verification key (vkey) witnesses to a transaction.

This function attaches a set of vkey witnesses to the given transaction.

Usage Example: 

cardano_transaction_t* tx = ...;                  // Initialized transaction
cardano_vkey_witness_set_t* vkey_witnesses = ...; // Initialized set of vkey witnesses

cardano_error_t result = cardano_transaction_apply_vkey_witnesses(tx, vkey_witnesses);

if (result == CARDANO_SUCCESS)
{
  // The vkey witnesses were successfully applied to the transaction
}
else
{
  // Handle the error
}

Parameters:
cardano_transaction_t *transaction

[inout] A pointer to the cardano_transaction_t structure representing the transaction to which the vkey witnesses will be applied.

cardano_vkey_witness_set_t *new_vkeys

[in] A pointer to the cardano_vkey_witness_set_t structure containing the set of vkey witnesses to be applied.

Returns:

CARDANO_SUCCESS if the vkey witnesses were successfully applied to the transaction, or an appropriate error code if an error occurred.

bool cardano_transaction_has_script_data(cardano_transaction_t *transaction)

Checks if a transaction contains script data.

This function examines a given cardano_transaction_t object to determine whether it includes script data, such as redeemers or datums. Script data is required for transactions involving Plutus scripts on the Cardano blockchain.

Usage Example: 

cardano_transaction_t* transaction = ...; // Assume transaction is already initialized

bool has_script_data = cardano_transaction_has_script_data(transaction);

if (has_script_data)
{
  printf("The transaction contains script data.\n");
}
else
{
  printf("The transaction does not contain script data.\n");
}

Parameters:
cardano_transaction_t *transaction

[in] A pointer to an initialized cardano_transaction_t object to be checked for script data.

Returns:

true if the transaction contains script data; otherwise, false.

cardano_error_t cardano_transaction_get_unique_signers(cardano_transaction_t *tx, cardano_utxo_list_t *resolved_inputs, cardano_blake2b_hash_set_t **unique_signers)

Extracts the unique set of public key hashes (signers) required to sign a Cardano transaction.

This function computes the unique set of signers for a given Cardano transaction by analyzing the transaction body and resolved inputs. This set is represented as a cardano_blake2b_hash_set_t containing the hashes of public keys that are required to authorize the transaction.

Parameters:
cardano_transaction_t *tx

[in] A pointer to an initialized cardano_transaction_t object that represents the Cardano transaction for which the unique signers are to be determined. This parameter is required and must not be NULL.

cardano_utxo_list_t *resolved_inputs

[in] A pointer to an initialized cardano_utxo_list_t object containing the list of resolved UTXOs (inputs) referenced in the transaction. If this parameters is NULL, the function will ignore inputs and collateral inputs.

cardano_blake2b_hash_set_t **unique_signers

[out] On successful execution, this will point to a newly created cardano_blake2b_hash_set_t object containing the unique public key hashes required to authorize the transaction. The caller is responsible for managing the lifecycle of this object. Specifically, the caller must release it by calling cardano_blake2b_hash_set_unref once it is no longer needed.

Returns:

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the unique signers were successfully computed, or an appropriate error code indicating the failure reason, such as CARDANO_ERROR_POINTER_IS_NULL if required inputs (tx or resolved_inputs) are NULL.

void cardano_transaction_unref(cardano_transaction_t **transaction)

Decrements the reference count of a cardano_transaction_t object.

This function is responsible for managing the lifecycle of a cardano_transaction_t object by decreasing its reference count. When the reference count reaches zero, the transaction is finalized; its associated resources are released, and its memory is deallocated.

Usage Example: 

cardano_transaction_t* transaction = cardano_transaction_new(major, minor);

// Perform operations with the transaction...

cardano_transaction_unref(&transaction);
// At this point, transaction is NULL and cannot be used.

Note

After calling cardano_transaction_unref, the pointer to the cardano_transaction_t object will be set to NULL to prevent its reuse.

Parameters:
cardano_transaction_t **transaction

[inout] A pointer to the pointer of the transaction object. This double indirection allows the function to set the caller’s pointer to NULL, avoiding dangling pointer issues after the object has been freed.

void cardano_transaction_ref(cardano_transaction_t *transaction)

Increases the reference count of the cardano_transaction_t object.

This function is used to manually increment the reference count of an cardano_transaction_t object, indicating that another part of the code has taken ownership of it. This ensures the object remains allocated and valid until all owners have released their reference by calling cardano_transaction_unref.

Usage Example: 

// Assuming transaction is a previously created transaction object

cardano_transaction_ref(transaction);

// Now transaction can be safely used elsewhere without worrying about premature deallocation

Note

Always ensure that for every call to cardano_transaction_ref there is a corresponding call to cardano_transaction_unref to prevent memory leaks.

Parameters:
cardano_transaction_t *transaction

A pointer to the cardano_transaction_t object whose reference count is to be incremented.

size_t cardano_transaction_refcount(const cardano_transaction_t *transaction)

Retrieves the current reference count of the cardano_transaction_t object.

This function returns the number of active references to an cardano_transaction_t object. It’s useful for debugging purposes or managing the lifecycle of the object in complex scenarios.

Usage Example: 

// Assuming transaction is a previously created transaction object

size_t ref_count = cardano_transaction_refcount(transaction);

printf("Reference count: %zu\n", ref_count);

Warning

This function does not account for transitive references. A transitive reference occurs when an object holds a reference to another object, rather than directly to the cardano_transaction_t. As such, the reported count may not fully represent the total number of conceptual references in cases where such transitive relationships exist.

Parameters:
const cardano_transaction_t *transaction

A pointer to the cardano_transaction_t object whose reference count is queried. The object must not be NULL.

Returns:

The number of active references to the specified cardano_transaction_t object. If the object is properly managed (i.e., every cardano_transaction_ref call is matched with a cardano_transaction_unref call), this count should reach zero right before the object is deallocated.

void cardano_transaction_set_last_error(cardano_transaction_t *transaction, const char *message)

Sets the last error message for a given cardano_transaction_t object.

Records an error message in the transaction’s last_error buffer, overwriting any existing message. This is useful for storing descriptive error information that can be later retrieved. The message is truncated if it exceeds the buffer’s capacity.

Note

The error message is limited to 1023 characters, including the null terminator, due to the fixed size of the last_error buffer.

Parameters:
cardano_transaction_t *transaction

[in] A pointer to the cardano_transaction_t instance whose last error message is to be set. If NULL, the function does nothing.

const char *message

[in] A null-terminated string containing the error message. If NULL, the transaction’s last_error is set to an empty string, indicating no error.

const char *cardano_transaction_get_last_error(const cardano_transaction_t *transaction)

Retrieves the last error message recorded for a specific transaction.

This function returns a pointer to the null-terminated string containing the last error message set by cardano_transaction_set_last_error for the given transaction. If no error message has been set, or if the last_error buffer was explicitly cleared, an empty string is returned, indicating no error.

Note

The returned string points to internal storage within the object and must not be modified by the caller. The string remains valid until the next call to cardano_transaction_set_last_error for the same transaction, or until the transaction is deallocated.

Parameters:
const cardano_transaction_t *transaction

[in] A pointer to the cardano_transaction_t instance whose last error message is to be retrieved. If the transaction is NULL, the function returns a generic error message indicating the null transaction.

Returns:

A pointer to a null-terminated string containing the last error message for the specified transaction. If the transaction is NULL, “Object is NULL.” is returned to indicate the error.