createpsbt - Bitcoin

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

This method creates a PSBT (Partially Signed Bitcoin Transaction) with the given inputs and outputs. The transaction is unsigned and can be signed later using wallets or signing devices.

Parameters

Parameter	Type	Required	Description
inputs	array	Yes	Array of input objects with txid and vout.
inputs[].txid	string	Yes	The transaction id of the UTXO to spend.
inputs[].vout	number	Yes	The output index of the UTXO to spend.
inputs[].sequence	number	No	The sequence number (default: depends on locktime).
outputs	array	Yes	Array of output objects mapping addresses to amounts.
locktime	number	No	Raw locktime (default: 0).
replaceable	boolean	No	Marks this transaction as BIP125-replaceable (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": "createpsbt",
    "params": [
        [{"txid": "ee652f0b40209bd02468de0c6336854f5efdd79fb865560aef2c46f4fa0b4a07", "vout": 0}],
        [{"bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq": 0.001}]
    ],
    "id": "getblock.io"
}'

Axios

Request

Rust

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "cHNidP8BAHUCAAAAASaBcTce3/KF6Tig7cez..."
}

Response Parameters

Field	Type	Description
result	string	The resulting unsigned PSBT in base64 format.

Use Case

The createpsbt method is essential for:

• Building unsigned transactions for hardware wallet signing

• Creating multi-signature transaction proposals

• Constructing complex transactions with multiple inputs/outputs

• Implementing cold storage spending workflows

• Building transaction batching systems

• Creating RBF-enabled transactions

Error Handling

Status Code	Error Message	Cause
403	Forbidden	Missing or invalid ACCESS-TOKEN.
-32602	Invalid params	Missing or malformed inputs/outputs arrays.
-8	Invalid parameter	Invalid address or amount in outputs.
-5	Invalid Bitcoin address	One of the output addresses is invalid.

Integration Notes

The createpsbt method helps developers:

• Build wallet applications with hardware wallet support

• Implement multi-party transaction construction

• Create offline transaction generation systems

• Support air-gapped signing workflows

• Enable secure cold storage spending