IMPORTANT NOTICE
For users of the now deprecated BitcoinII-Core Releases versions 29.0.0 and 29.0.1, BitcoinII-Core Release Version 29.1.0 is a MANDATORY update! This updated version includes the edits necessary to switch from older (now offline) seed servers to a new seed server maintained under the BitcoinII Organization, as well as updated checkpoints.
To upgrade, simply shut down your BitcoinII node and replace the binary itself. In some instances, BitcoinII Core may request to rescan or resysnc the blockchain depending on your pruning configuration. Allow it to do so. No other actions will be required by the user. Users of Legacy Version 27.0.0 will need to upgrade to Legacy Version 27.1.0
Users of Legacy Windows 64 Bit Operating Systems (Windows 7 versions) will need to use the BitcoinII Legacy Binary (version 27.1) available at: https://github.com/BitcoinII-Dev/BitcoinII. Due to new mempool policies inherited from upstream Bitcoin Core, users of the Legacy Binaries will need to ensure that R.B.F. (Replace By Fee) is activated for all outgoing transactions to ensure their transactions are included in blocks once the majority of the network completes the upgrade to BitcoinII v29.1.0.
For those using older releases of Linux with older versions of C/C++ tool chains and libraries (i.e Ubuntu 20.04) that wish to run v29.1.0, they should download the source code and compile their binaries locally. The release binaries are linked against newer versions of these libraries (Ubuntu 24.04).
In the event BitcoinII Core v29.1.0 does not recognize a wallet.dat file generated by BitcoinII Core v27.0.0, you will want to first dump and store the private keys/descriptors from the wallet using v27.0.0 and then import them into a new wallet.dat file using v29.1.0.
Follow the instructions here: https://github.com/Bitcoin-II/BitcoinII-Core/blob/main/privatekeydemo.txt
For an immediately usable, binary version of the BitcoinII Core software, see https://github.com/Bitcoin-II/BitcoinII/releases/
BitcoinII is a nearly 1:1 re-launch of the Bitcoin protocol.
BitcoinII Core connects to the BitcoinII peer-to-peer network to download and fully validate blocks and transactions. It also includes a wallet and graphical user interface, which can be optionally built.
Further information about BitcoinII Core is available in the doc folder.
BitcoinII Core is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/licenses/MIT.
The main branch is regularly built (see doc/build-*.md for instructions) and tested, but it is not guaranteed to be
completely stable. Tags are created
regularly from release branches to indicate new official, stable release versions of BitcoinII Core.
The https://github.com/Bitcoin-II/BitcoinII-core/gui repository is used exclusively for the development of the GUI. Its master branch is identical in all monotree repositories. Release branches and tags do not exist, so please do not fork that repository unless it is for development reasons.
The contribution workflow is described in CONTRIBUTING.md and useful hints for developers can be found in doc/developer-notes.md.
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.
Developers are strongly encouraged to write unit tests for new code, and to
submit new unit tests for old code. Unit tests can be compiled and run
(assuming they weren't disabled during the generation of the build system) with: ctest. Further details on running
and extending unit tests can be found in /src/test/README.md.
There are also regression and integration tests, written
in Python.
These tests can be run (if the test dependencies are installed) with: build/test/functional/test_runner.py
(assuming build is your build directory).
The CI (Continuous Integration) systems make sure that every pull request is built for Windows, Linux, and macOS, and that unit/sanity tests are run automatically.
Changes should be tested by somebody other than the developer who wrote the code. This is especially important for large or high-risk changes. It is useful to add a test plan to the pull request description if testing the changes is not straightforward.
Changes to translations as well as new translations can be submitted to Bitcoin Core's Transifex page.
Translations are periodically pulled from Transifex and merged into the git repository. See the translation process for details on how this works.
Important: We do not accept translation changes as GitHub pull requests because the next pull from Transifex would automatically overwrite them again.
