Welcome to the flax-blockchain project! We are happy that you are taking a look at the code for Flax, a proof of space and time cryptocurrency.

A lot of fascinating new cryptography and blockchain concepts are used and implemented here. This repo includes the code for the Flax full node, farmer, and timelord (in flax folder), which are all written in python. It also includes a verifiable delay function implementation that it imports from the chiavdf repo (in c/c++), and a proof of space implementation that it imports from the chiapos repo. BLS signatures are imported from the bls-signatures repo as blspy. There is an additional dependency on the chiabip158 repo. For major platforms, binary and source wheels are shipped to PyPI from each dependent repo. Then flax-blockchain can pip install those from PyPI or they can be prepackaged as is done for the Windows installer. On unsupported platforms, pip will fall back to the source distributions, to be compiled locally.

If you want to learn more about this project, read the wiki, or check out the green paper.

Please review this diagram, to better understand the git workflow.

We would be pleased to accept code contributions to this project. As we have now released, the main priority is improving the mainnet blockchain. You can visit our Trello project board to get a sense of what is in the backlog. Generally, things to the left are in progress or done. Some things go through "Coming up soon", but some will come directly out of other columns. Usually, the things closer to the top of each column are the ones that will be worked on soonest. If you are interested in cryptography, math, or just like hacking in python, there are many interesting problems to work on. Contact any of the team members on Discord, which we use as the main communication method. You can also comment on any Trello card.

We ask that external contributors create a fork of the main branch for any feature work they wish to take on.

Members of the Flax organization may create feature branches from the main branch.

In the event an emergency fix is required for the release version of Flax, members of the Flax organization will create a feature branch from the current release branch latest.

Branching Strategy Diagram

1. All changes go into the main branch.
2. Main is stable at all times, all tests pass.
3. Features (with tests) are developed and fully tested on feature branches, and reviewed before landing in main.
4. Flax Network's nodes on the public testnet are running the latest version x.y.z.
5. The main branch will have a long running beta testnet to allow previewing of changes.
6. Pull Request events may require a beta testnet review environment. At the moment this is at the discretion of the reviewer.
7. Hotfixes land in the release branch they fix, and all later versions. (This will be achieved by regularly merging from 1.3.x to main).
8. Hotfixes that are emergency fixes for a specific version will be merged into (???), and removed from down-stream branches. This allows future merges without issues.
9. Whoever develops a hotfix is also responsible for merging it into all later branches.
10. A release branch (e.g. 1.3.x) will be cut prior to a release, in order to separate work that should go into the release from work going into the next major release (main branch). (This pre-release branch will also have a beta testnet spun up for preview).
11. All Merge events will be squash merged.

The first time the tests are run, BlockTools will create and persist many plots. These are used for creating proofs of space during testing. The next time tests are run, this will not be necessary. Look at the pytest.ini file to configure how the tests are run. For example, for more logging: change the log level from WARNING to INFO, change -n auto to -n 0 and set log_cli = True.

sh install.sh -d
. ./activate
black . && isort benchmarks build_scripts flax tests tools *.py && mypy && flake8 benchmarks build_scripts flax tests tools *.py
py.test tests -v --durations 0

The black library is used as an automatic style formatter to make things easier. The flake8 library helps ensure consistent style. The Mypy library is very useful for ensuring objects are of the correct type, so try to always add the type of the return value, and the type of local variables. The isort library is used to sort, group and validate imports in all python files.

If you want verbose logging for tests, edit the tests/pytest.ini file.

We provide a pre-commit configuration which triggers several useful hooks (including linters/formatter) before each commit you make if you installed and set up pre-commit. This will help to reduce the time you spend on failed CI jobs.

To install pre-commit on your system see https://pre-commit.com/#installation. After installation, you can either use it manually with pre-commit run or let it trigger the hooks automatically before each commit by installing the provided configuration with pre-commit install.

1. Install python extension
2. Set the environment to ./venv/bin/python
3. Install mypy plugin
4. Preferences > Settings > Python > Linting > flake8 enabled
5. Preferences > Settings > Python > Linting > mypy enabled
6. Preferences > Settings > Formatting > Python > Provider > black
7. Preferences > Settings > mypy > Targets: set to ./flax and ./tests

Pycharm is an amazing and beautiful python IDE that some of us use to work on this project. If you combine it with python black and formatting on save, you will get a very efficient workflow. It's also especially efficient for git branching, cherry-picking, committing and pushing.

1. Run blackd in a terminal
2. Install BlackConnect plugin
3. Set to run python black on save
4. Set line length to 120
5. Install the linters in the root directory

The current official testnet is testnet10. Look at flax/util/initial_config.yaml to see the configuration parameters for each testnet. Information on how to use the testnet can be found in the wiki.

Prior to proposing changes to main, proposers should consider if running a beta testnet review environment will make the reviewer more effective when evaluating a change. Changes that impact the blockchain could require a review environment before acceptance into main. This is at the discretion of the reviewer. Flax organization members have been granted CI access to deploy beta testnets. If you are not a Flax organization member, you can enquire about deploying a beta testnet in the public dev Discord channel.

To propose changes, please make a pull request to the main branch. See Branching Strategy above.

To propose changes for the production releases of Flax, please make a pull request to the latest release branch.

By contributing to this repository, you agree to license your work under the Apache License Version 2.0, or the MIT License, or release your work to the public domain. Any work contributed where you are not the original author must contain its license header with the original author(s) and be in the public domain, or licensed under the Apache License Version 2.0 or the MIT License.