combinepsbt - Bitcoin

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

This method combines multiple partially signed Bitcoin transactions (PSBTs) into one transaction. All PSBTs must be for the same transaction (same inputs and outputs).

Parameters

Parameter	Type	Required	Description
txs	array	Yes	An array of base64 strings of partially signed transactions.

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "combinepsbt",
    "params": [["cHNidP8BAHUCAAAAASaBcTce...", "cHNidP8BAHUCAAAAASaBcTce..."]],
    "id": "getblock.io"
}'

Axios

Request

Rust

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "cHNidP8BAHUCAAAAASaBcTce3/KF6Tig7cezh..."
}

Response Parameters

Field	Type	Description
result	string	The base64-encoded partially signed transaction with all signatures combined.

Use Case

The combinepsbt method is essential for:

• Multi-signature wallet implementations

• Combining signatures from multiple hardware wallets

• Collaborative transaction signing workflows

• CoinJoin transaction construction

• Escrow services requiring multiple signers

• Corporate treasury management with multiple approvers

Error Handling

Status Code	Error Message	Cause
403	RBAC: Access denied	Missing or invalid ACCESS-TOKEN.
-22	Invalid params	The params array is malformed.
-1	Missing param	the param array is empty

Integration Notes

The combinepsbt method helps developers:

• Build multi-party signing protocols

• Implement threshold signature schemes

• Create collaborative custody solutions

• Support air-gapped hardware wallet workflows

• Enable distributed key management systems