combinerawtransaction - Bitcoin

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

This method combines multiple partially signed raw transactions into one transaction. The combined transaction may be another partially signed transaction or a fully signed transaction.

Parameters

Parameter	Type	Required	Description
txs	array	Yes	An array of hex 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": "combinerawtransaction",
    "params": [["0200000001aad73931018bd25f84ae4...", "0200000001aad73931018bd25f84ae4..."]],
    "id": "getblock.io"
}'

Axios

Request

Rust

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0200000001aad73931018bd25f84ae400b68d85d7faff77707c1e6b6c6b8b4e2f7..."
}

Response Parameters

Field	Type	Description
result	string	The hex-encoded raw transaction with all signatures combined.

Use Case

The combinerawtransaction method is essential for:

• Multi-signature transaction completion

• Combining signatures from offline signers

• Legacy multi-sig wallet implementations

• Transaction aggregation services

• Batch signing operations

• Compatibility with older signing tools

Error Handling

Status Code	Error Message	Cause
403	RBAC: access denied	Missing or invalid ACCESS-TOKEN.
-22	TX decode failed	One or more transaction hex strings are invalid.
-8	Transactions not compatible	The transactions have different inputs/outputs.

Integration Notes

The combinerawtransaction method helps developers:

• Support legacy multi-sig workflows

• Integrate with older hardware wallets

• Build backward-compatible signing solutions

• Migrate from raw transactions to PSBT format

• Handle mixed signing environments