consolidate-utxo

Tool which helps consolidate your unspent transactions outputs

!test status

When you have a long-running bitcoin wallet with big transaction history, you might start getting errors like Transaction too large during the withdrawal. That's because you have a lot small UTXOs (Unspent transaction outputs) and when bitcoin node tries to build transaction it became too large. To fix this you need to Consolidate your UTXO set.

Designed for Bitcoin version >= 0.17

How it works

consolidate-utxo asks all unspent outputs from your bitcoin node, filters them by amount (0.0001 by default) and tries to build a transaction to send them all back to the node in one output. If the resulting transaction is too big, it will lower number of inputs and try again.

How to install

This program is written in JavaScript and to run in you need NodeJS to be installed on your system.

To install it globally run

``bash
npm install -g consolidate-utxo
`

Or you can create temporary project to install it locally

`bash
mkdir tmpprj
cd tmpprj
npm init
npm install consolidate-utxo
`

If you have installed it locally, you need to run it using npx

`bash
npx consolidate-utxo
`

How to use

consolidate-utxo tool needs RPC server to be enabled in your bitcoin.conf and rpc username and password to be set.

bitcoin.conf example:
`
server=1
rpcuser=root
rpcpassword=toor
`

Then you can run
`bash
consolidate-utxo --username root --password toor
`

Default transaction fee is set to the lowest possible value - 1 sat/byte. You can change it by --fee parameter

Other options:

`bash
~ consolidate-utxo --help

Consolidates UTXO on your bitcoin node.

cutxo --username root --password toor --amount 0.0001 --fee 2

--help Show help.
--host Host to connect to. Default is "localhost".
--port Port where bitcoin json-rpc is listerning. Default is "8332".
--limit Limit number of inputs.
--amount Maximum amount for UTXO to include in transaction. Default is "0.0001".
--fee Fee for new transaction in Satoshi/byte. Default is "1".
`

Testing

To run tests you need to run bitcoin node in regtest mode and then run application tests

`bash
docker-compose up -d
npm test
`

Example

Here is example of running consolidate-utxo against node with 4000 UTXOs on testnet:

`bash
$ consolidate-utxo --username root --password toor --amount 0.001 --port 18332
Output address: 2MyrmzDNT7Xe8QqYwWQtQFsB73TeYg1Q3jm
Picking up maximum number of inputs...
trying: 4775
trying: 2387
trying: 3581
trying: 2984
trying: 2685
trying: 2536
trying: 2461
trying: 2424
trying: 2442
trying: 2433
trying: 2437
trying: 2439
trying: 2438
trying: 2437
success
Signing transaction...
Finalizing transaction...
Transaction created

Number of inputs: 2437
Inputs total amount: 2.437
Output amount: 2.43473489
Fee: 0.00226511
Output address: 2MyrmzDNT7Xe8QqYwWQtQFsB73TeYg1Q3jm

Are you sure you want to broadcast the transaction? yes
Broadcasting transaction...
Done!
b4a568966f3b7f981ad2f98c12adead32066f69a816c390218597dfc096cf99f
``

You can check resulting transaction on blockchain explorer

License

MIT