Signers

Model fee payers, partial signers, modifying signers, and sending signers explicitly.

Solana Kit treats signers as capabilities, not only as key material. That gives you a better fit for real-world flows involving wallets, mobile adapters, remote signers, and multi-party signing.

Why the signer model matters#

In many SDKs, “a signer” is just a private key. In production Solana apps, that is often not enough.

You may need to represent:

a local key pair that signs directly
a wallet that signs and sends in one step
a system that mutates the transaction before signing
a fee payer that differs from another signing authority
a partially signed transaction that must be completed later

Common signer interfaces#

KeyPairSigner: local Ed25519 key pair plus signing methods
FeePayerSigner: signer designated as the fee payer
TransactionPartialSigner: can contribute one or more transaction signatures
TransactionModifyingSigner: can edit a transaction before signature application
TransactionSendingSigner: can sign and submit a transaction
MessagePartialSigner: signs off-chain messages instead of transactions

Build a transaction around signers#

When your signers live on the transaction message itself, the message-level helpers are still the most ergonomic path.

final signer = await generateKeyPair();

final message = createTransactionMessage()
    .pipe(setTransactionMessageFeePayerSigner(signer));

When signer resolution happens outside the message, drop to the explicit transaction-level helpers:

Sign a compiled transaction with explicit signers#

Use the transaction-level signer helpers when your signers are resolved outside of the message itself or when you need to work with a compiled Transaction directly.

import 'package:solana_kit/solana_kit.dart';

Future<void> partiallySign(
  List<Object> signers,
  Transaction transaction,
) async {
  final partiallySigned = await partiallySignTransactionWithSigners(
    signers,
    transaction,
  );

  print(partiallySigned.signatures.length);
}

This is especially useful for wallet adapters, remote signers, or orchestration layers that gather signatures in more than one step.

Why explicit roles help#

This separation gives you:

better modeling for wallet integrations
more honest test seams
cleaner handling of partial signatures
safer transaction pipelines for complex orchestration