A fast & nimble SPV server for Bitcoin Cash.
(C) 2019-2020 Calin Culianu firstname.lastname@example.org
GPLv3. See the included
LICENSE.txt file or visit gnu.org and read the license.
- Fast: Written in 100% modern
C++17using multi-threaded and asynchronous programming techniques.
- A drop-in replacement for ElectronX/ElectrumX: The initial release of this server is 100% protocol-level compatible with the ElectronX/ElectrumX 1.4.2 protocol. Existing server admins should feel right at home with this software since installation and management of it is nearly identical to ElectronX/ElectrumX server.
- Cross-platform: While this codebase was mainly developed and tested on MacOS, Windows and Linux, it should theoretically work on any modern OS (such as *BSD) that has Qt5 Core and Qt5 Networking available.
5.12.5or above (I use
5.12.4(or earlier) is not supported.
- A modern, 64-bit
clangis recommended but
G++also works. MSVC on Windows is not supported (please use
MinGW G++instead, which ships with Qt Open Source Edition for Windows).
How To Compile
It's recommended you use Qt Creator.
- Get the latest version of Qt Open Source Edition for your platform.
- Point the Qt Creator IDE at the
- Set the build configuration to "Release". Hit Build. It should "just work".
You may also build from the CLI (on Linux and MacOS):
- Make sure you have
qmakein your path and all the requisite Qt5 dev libs installed.
qmake(to generate the Makefile)
make -j8(replace 8 here with the number of cores on your machine)
A note for Linux users: You may have to install the Qt5 networking package separately such as
libqt5network5 (depending on your distribution). You also need
libbz2-dev otherwise compilation will fail. If you are having trouble finding the required Qt versions, you can try this link: https://launchpad.net/~beineri (for Ubuntu/Debian ppas).
A note for Windows users:
Qt 5.13.2 (or above) with
MinGW G++ 7.x.x is the compiler/Qt kit you should be using. MSVC is not supported by this codebase at the present time.
What to do if compiling fails
If you have problems compiling, the most likely culprit would be your compiler not being
C++17 compliant (please use a recent verson of
clang on Linux, Apple's
Xcode on Mac, or
MinGW G++ 7.x on Windows).
The other likely culprit is the fact that at the present time I have included a statically-built
librocksdb in the codebase. There are versions of this library for Windows, Mac, and Linux included right in the source tree, and
Fulcrum.pro looks for them and links to them. Instructions are included within the
Fulcrum.pro project file about how to build your own static
librocksdb if the bundled one does not work on your system.
If you are still having trouble, file an issue here in this github.
Linking against the system
You may optionally build against the system rocksdb (Linux only) if your distribution offers
6.5.x or newer.
qmake features=(to generate the Makefile without the
make clean && make -j8(replace 8 here with the number of cores on your machine)
Note: Some Linux distributions have been known to package
librocksdb.so incorrectly. See here for an example, so until I can be confident most distributions do it right, I am considering using the system
librocksdb.so an experimental feature for the time being (in principle it should work ok if the library is compiled correctly).
Execute the binary, with
-h to see the built-in help, e.g.
./Fulcrum -h. You can set most options from the CLI, but you can also specify a config file as an argument. See:
- doc/fulcrum-example-config.conf in the source tree. This sample config file is very well documented with comments.
- doc/fulcrum-quick-config.conf in the source tree. This is a more abbreviated config file you can use as a starting point as well.
Fulcrum requires a
bitcoind instance running either on
regtest for testing), which you must tell it about via the CLI options or via the config file. You also need to tell it what port(s) to listen on and optionally what SSL certificates to use (if using SSL). Note: Electron Cash at this time no longer supports connecting to non-SSL servers, so you should probably configure SSL for production use.
It is recommended you specify a data dir (
-D via CLI or
datadir= via config file) on an SSD drive for best results. Synching against
testnet should take you about 10-20 minutes (more on slower machines), and mainnet can take anywhere from 4 hours to 20+ hours, depending on machine and drive speed. I have not tried synching against mainnet on an HDD and it will probably take days if you are lucky.
Once the server finishes synching it will behave like an ElectronX/ElectrumX server and it can receive requests from Electron Cash.
You may also wish to read the Fulcrum manpage.
Admin Script: FulcrumAdmin
Fulcrum comes with an admin script (
Python 3.6+ is required on the system to run this script). You may send commands to
Fulcrum using this script. The script requires that an admin port (config var
admin=, CLI arg
-a) be configured for your server. To run the script, execute
./FulcrumAdmin -h and you will see a list of possible subcommands that you can send to
Fulcrum. Here are two of the most popular commands to try (the below assumes the
admin port is on port
$ ./FulcrumAdmin -p 8000 peers $ ./FulcrumAdmin -p 8000 clients $ ./FulcrumAdmin -p 8000 getinfo
(This section is incomplete for now, all apologies -- more documentation is coming soon!)
Big Endian Architectures
The code is more or less configured to assume a "little endian" architecture by default (which is what all Intel x86/x86_64 are). If you're on a big endian machine, on Linux it should just auto-detect that fact. However, on other OS's such as BSD, if you're on a big endian machine, you may need to uncomment this line from the
# DEFINES += WORDS_BIGENDIAN
This codebase will not compile correctly (or at all) using MSVC. Please use the
G++ kit in Qt Creator to build this software.
If you have
clang on your system, configure the project to use it as the compiler preferentially over
G++ works too, but
clang is preferred.
Everything should just work (I use MacOS as my dev machine).
Q: Why Qt? This isn't a GUI app!
A: Yes, I know. However, Qt is a very robust, cross-platform and fast application framework. You can use its "Core" library for console apps, servers, etc. It has great network support and other basic things a programmer needs to get stuff done.
Sure! Send BCH here: