finalizepsbt - Bitcoin

Example code for the finalizepsbt JSON RPC method. Сomplete guide on how to use finalizepsbt JSON RPC in GetBlock Web3 documentation.

This method finalizes the inputs of a PSBT. If the transaction is fully signed, it will produce a network-serialized transaction that can be broadcast.

Parameters

Parameter	Type	Required	Description
psbt	string	Yes	A base64 string of a PSBT.
extract	boolean	No	If true and the transaction is complete, extract and return the complete transaction in hex (default: true).

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "finalizepsbt",
    "params": ["cHNidP8BAHUCAAAAASaBcTce3/KF6Tig7cez...", true],
    "id": "getblock.io"
}'

Axios

Request

Rust

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "psbt": "cHNidP8BAHUCAAAAASaBcTce3/KF6Tig7cez...",
        "hex": "0200000001074a0bfaf4462cef0a5665b89fd7fd5e4f8536630cde6824d09b20400b2f65ee000000006a47304402207...",
        "complete": true
    }
}

Response Parameters

Field	Type	Description
psbt	string	The finalized PSBT in base64 format (if not extracted).
hex	string	The hex-encoded network transaction (if complete and extract=true).
complete	boolean	Whether the transaction has a complete set of signatures.

Use Case

The finalizepsbt method is essential for:

• Completing signed PSBTs for broadcast

• Converting PSBTs to raw transactions

• Verifying PSBT signing completion

• Building transaction finalization workflows

• Preparing transactions for network submission

• Supporting hardware wallet signing flows

Error Handling

Status Code	Error Message	Cause
403	Forbidden	Missing or invalid ACCESS-TOKEN.
-22	TX decode failed	The PSBT string is malformed.

Integration Notes

The finalizepsbt method helps developers:

• Complete multi-party signing workflows

• Prepare transactions for broadcast

• Validate signing completion

• Support hardware wallet integrations

• Build transaction submission pipelines