Struct FeeForwarderService

pub struct FeeForwarderService<P>
where
    P: StellarProviderTrait + Send + Sync,
{ /* private fields */ }

Service for building FeeForwarder transactions

Implementations

impl<P> FeeForwarderService<P>

where P: StellarProviderTrait + Send + Sync,

pub fn new(fee_forwarder_address: String, provider: Arc<P>) -> Self

Create a new FeeForwarderService

Arguments

• fee_forwarder_address - The deployed FeeForwarder contract address
• provider - Stellar provider for network queries

pub fn build_user_auth_entry_standalone( fee_forwarder_address: &str, params: &FeeForwarderParams, requires_target_auth: bool, ) -> Result<SorobanAuthorizationEntry, FeeForwarderError>

Build a user authorization entry without requiring a FeeForwarderService instance

This static method is useful when you don’t have an Arc<P> provider but still need to build authorization entries for the FeeForwarder.

pub fn build_relayer_auth_entry_standalone( fee_forwarder_address: &str, params: &FeeForwarderParams, ) -> Result<SorobanAuthorizationEntry, FeeForwarderError>

Build a relayer authorization entry without requiring a FeeForwarderService instance

The FeeForwarder contract requires the relayer to authorize receiving the fee payment. This creates an auth entry for the relayer’s authorization of the forward call.

Arguments

• fee_forwarder_address - The FeeForwarder contract address
• params - FeeForwarder transaction parameters

Returns

A SorobanAuthorizationEntry for the relayer (with empty signature for simulation)

pub fn fee_forwarder_address(&self) -> &str

Get the FeeForwarder contract address

pub fn build_forward_args_for_invoke_contract_args( fee_forwarder_address: &str, params: &FeeForwarderParams, ) -> Result<ScVec, FeeForwarderError>

Public wrapper for building forward args (for serializing InvokeContractArgs)

pub fn parse_contract_address_public( address: &str, ) -> Result<ScAddress, FeeForwarderError>

Public wrapper for parsing a contract address

pub async fn get_expiration_ledger( &self, validity_seconds: u64, ) -> Result<u32, FeeForwarderError>

Calculate the expiration ledger for authorization

Arguments

• validity_seconds - How long the authorization should be valid

Returns

The ledger number when the authorization expires

pub fn build_user_auth_entry( &self, params: &FeeForwarderParams, requires_target_auth: bool, ) -> Result<SorobanAuthorizationEntry, FeeForwarderError>

Build the user authorization entry for FeeForwarder.forward()

This creates the authorization structure that the user needs to sign. The authorization includes sub-invocations for:

• fee_token.approve(user, fee_forwarder, max_fee_amount, expiration_ledger)
• target_contract.target_fn(target_args) (if requires_target_auth is true)

Arguments

• params - FeeForwarder transaction parameters
• requires_target_auth - Whether the target contract call requires user authorization

Returns

A SorobanAuthorizationEntry that the user needs to sign

pub fn serialize_auth_entry( auth: &SorobanAuthorizationEntry, ) -> Result<String, FeeForwarderError>

Serialize an authorization entry to base64 XDR

pub fn deserialize_auth_entry( xdr: &str, ) -> Result<SorobanAuthorizationEntry, FeeForwarderError>

Deserialize an authorization entry from base64 XDR

pub fn build_invoke_operation( &self, params: &FeeForwarderParams, auth_entries: Vec<SorobanAuthorizationEntry>, ) -> Result<Operation, FeeForwarderError>

Build the InvokeHostFunction operation for FeeForwarder.forward()

This creates the operation that will be included in the transaction. The authorization entries should include both user and relayer signatures.

Arguments

• params - FeeForwarder transaction parameters
• auth_entries - Signed authorization entries (user + relayer)

pub fn build_invoke_operation_standalone( fee_forwarder_address: &str, params: &FeeForwarderParams, auth_entries: Vec<SorobanAuthorizationEntry>, ) -> Result<Operation, FeeForwarderError>

Build the InvokeHostFunction operation without requiring a service instance.

This static method is useful when you don’t have an Arc<P> provider but still need to build InvokeHostFunction operations for the FeeForwarder.