Build Custom Transactions

The built-in helpers cover common flows. Use wallet.buildTransaction(...) or wallet.build_transaction(...) when you still want hosted preparation but need your own instruction set.

What it does

The custom transaction builder prepares a transaction for an existing Swig wallet from a list of Solana instructions you provide. Use it when:

the transfer and swap helpers are not enough
you already know the exact instruction bundle you want to run
you still want the backend to prepare the final wallet transaction

Example

TypeScript

const prepared = await wallet.buildTransaction({
  feePayer,
  instructions: [
    {
      programId: targetProgramId,
      accounts: [
        {
          pubkey: writableAccount,
          isWritable: true,
        },
        {
          pubkey: readonlyAccount,
        },
      ],
      data: Buffer.from(instructionData).toString('base64'),
    },
  ],
  addressLookupTableAccounts: [lookupTableAddress],
});

from swig_developer_sdk import SolanaAccountMeta, SolanaInstructionInput

prepared = await wallet.build_transaction(
    fee_payer=fee_payer,
    instructions=(
        SolanaInstructionInput(
            program_id=target_program_id,
            accounts=(
                SolanaAccountMeta(
                    pubkey=writable_account,
                    is_writable=True,
                ),
                SolanaAccountMeta(pubkey=readonly_account),
            ),
            data=instruction_data,
        ),
    ),
    address_lookup_table_accounts=(lookup_table_address,),
)

The SDK normalizes the instruction input and sends it to POST /transaction/prepare/custom. The API returns the prepared transaction for your client-signing and submission flow.

What still applies

This is still a prepared transaction result. That means:

your app still checks signatureRequests / signature_requests
the client still signs if required
your app still chooses direct submission or sponsor submission

Full protocol control

Use the Protocol SDK for full protocol control, custom role or action construction, or instruction-by-instruction authoring.

Start Here

Set Up Access

Build Wallet Flows

Add Recovery

Operate in Production

Workspace Admin

Build Custom Transactions

What it does

Example

What still applies

Full protocol control

​What it does

​Example

​What still applies

​Full protocol control

What it does

Example

What still applies

Full protocol control