signAuthEntries

Signs authorization entries in the transaction.

This method is used for multi-authorization workflows where the contract invocation requires authorization from specific accounts (other than the transaction invoker).

Use Cases

1. Atomic Swaps: Alice and Bob both need to authorize their token transfers

2. Multi-Signature Operations: Multiple parties must approve a contract action

3. Remote Signing: One party signs locally, another signs on a remote server

Parameters

• authEntriesSigner: The KeyPair to sign with. Can be public-key-only if using delegate.

• validUntilLedgerSequence: Optional expiration ledger. Defaults to current + 100 (~8.3 minutes).

• authorizeEntryDelegate: Optional function for custom/remote signing logic.

Basic Usage (Local Signing)

val tx = swapClient.invoke<Unit>(
    functionName = "swap",
    parameters = swapParams,
    source = invokerAccount,
    signer = invokerKeyPair
)

// Sign auth entries for Alice (has private key)
tx.signAuthEntries(aliceKeyPair)

// Sign auth entries for Bob (has private key)
tx.signAuthEntries(bobKeyPair)

// Submit the fully-signed transaction
val result = tx.signAndSubmit(invokerKeyPair)

Remote Signing (Delegate Pattern)

// Bob's signing happens on a remote server
val bobPublicOnly = KeyPair.fromAccountId(bobId)
tx.signAuthEntries(
    authEntriesSigner = bobPublicOnly,
    authorizeEntryDelegate = { entry, network ->
        // Send to remote server
        val entryXdr = entry.toXdrBase64()
        val signedXdr = httpClient.post("/sign", entryXdr)

        // Return signed entry
        SorobanAuthorizationEntryXdr.fromXdrBase64(signedXdr)
    }
)

Custom Expiration

// Get current ledger
val latestLedger = server.getLatestLedger()

// Set expiration to 1 hour from now (~720 ledgers)
tx.signAuthEntries(
    authEntriesSigner = aliceKeyPair,
    validUntilLedgerSequence = latestLedger.sequence + 720
)

How It Works

1. The method finds all auth entries that match the signer's address

2. For each matching entry:

• Sets the expiration ledger

• Signs the entry using Auth.authorizeEntry() or the delegate

• Updates the signature in the entry

3. Rebuilds the transaction with the updated auth entries

Parameters

Throws