Extension Wallet
Integration
SOLANA Network
Sign Transaction

Sign Transaction

Cosmostation Solana provider supports transaction signing without broadcasting via the Solana Wallet Standard.

This flow is commonly used when:

  • A dApp needs to collect signatures first
  • Transactions are submitted later by a backend or relayer
  • Multiple signatures are required before sending
  • You want to inspect or modify a signed transaction before execution

Cosmostation implements the following Solana wallet-standard features:

  • SolanaSignTransaction
  • SolanaSignAndSendTransaction

This section focuses on SolanaSignTransaction, which signs a transaction but does not submit it to the network.

Using Wallet Adapter

When using the Solana Wallet Adapter, transaction signing is handled through the connected wallet instance.

import { useWallet } from '@solana/wallet-adapter-react';
import type { Transaction, VersionedTransaction } from '@solana/web3.js';
 
const { signTransaction, publicKey } = useWallet();
 
const signTx = async (transaction: Transaction | VersionedTransaction) => {
  if (!publicKey || !signTransaction) {
    throw new Error('Wallet not connected');
  }
 
  const signedTransaction = await signTransaction(transaction);
 
  // signedTransaction is returned but NOT sent to the network
  return signedTransaction;
};

Behavior

  • The wallet UI prompts the user to approve the transaction

  • The transaction is signed locally

  • No RPC submission is performed

  • The signed transaction can be:

    • Stored
    • Sent to a backend
    • Combined with other signatures
    • Submitted later via RPC

Cosmostation follows the same behavior as Phantom and other Solana Wallet Standard–compatible wallets.

Using Vanilla Provider

If you are not using Wallet Adapter, you can interact with the Cosmostation Solana provider directly.

Accessing the Provider

const solana = () => {
  if ('cosmostation' in window) {
    return window.cosmostation.solana;
  }
 
  window.open('https://cosmostation.io/wallet/#extension');
};
 
const provider = solana();

Signing a Transaction

import { VersionedTransaction } from '@solana/web3.js';
 
const signTransaction = async (serializedTx: Uint8Array) => {
  const transaction = VersionedTransaction.deserialize(serializedTx);
 
  const [{ signedTransaction }] = await provider.signTransaction({
    transaction: transaction.serialize(),
  });
 
  return signedTransaction;
};

Returned Data

The signTransaction method returns:

type SolanaSignTransactionOutput = {
  signedTransaction: Uint8Array;
};

This value represents the fully signed transaction payload, ready for:

  • RPC submission
  • Further processing
  • Multi-signature aggregation

References

Connect & AccountSign Message