• one ledger(block) has one transaction
• sibling(s) means the nodes in the same quorum
• ballot has one slot, and one slot has one transaction
• to make story simple and easy, the keypair of stellar will be used

1. check latest transaction id(latest transaction id)
   1. compare between local transaction id and siblings
   2. if different
   3. catchup
2. catched up

1. validate transaction
   1. if it is not valid, response 401
2. check the ballot is opened or not
3. if opened, wait until the ballot is closed
   1. the received transaction go to the transaction pool
4. if closed,
   1. check the siblings ballot is opened or not
   2. if opened ballot is found,
      1. check the transaction in ballot is already handled in local or not
      2. if it is already handled, skipt it
      3. if not, open new ballot with that ballot
      4. wait until the ballot is closed
5. start new ballot with new transaction

1. broadcast the ballot to siblings
2. if all accept new ballot
   1. start consensus
3. if not,
   1. if another node has the opened ballot with previous transaction id
      1. wait until that ballot is closed

1. receive the result of validation of other sibling
2. if the count of accepted is over threshold,
   1. broadcast closing ballot signal to the siblings
3. got close signal
   1. save the transaction in ballot to the storage

• Python 3.6.x or higher
• nothging :)

$ apt install python3 python3-pip
$ pip3 install virtualenv

$ brew install python3
$ pip install virtualenv

$ virtualenv ./simple-fba
Using base prefix '/usr'
New python executable in /root/simple-fba/bin/python3
Also creating executable in /root/simple-fba/bin/python
Installing setuptools, pip, wheel...cdone.
$ cd simple-fba
$ mkdir src
$ cd src
$ git clone https://github.com/spikeekips/simple-fba

$ python setup.py develop

For example, we will run 6 nodes with the different port in the same machine.

$ simple-fba-node.py -init -name=node0 -port=5000 -siblings=localhost:5001,localhost:5002,localhost:5003,localhost:5004,localhost:5005
$ simple-fba-node.py -init -name=node1 -port=5001 -siblings=localhost:5000,localhost:5002,localhost:5003,localhost:5004,localhost:5005
$ simple-fba-node.py -init -name=node2 -port=5002 -siblings=localhost:5001,localhost:5000,localhost:5003,localhost:5004,localhost:5005
$ simple-fba-node.py -init -name=node3 -port=5003 -siblings=localhost:5001,localhost:5002,localhost:5000,localhost:5004,localhost:5005
$ simple-fba-node.py -init -name=node4 -port=5004 -siblings=localhost:5001,localhost:5002,localhost:5003,localhost:5000,localhost:5005
$ simple-fba-node.py -init -name=node5 -port=5005 -siblings=localhost:5001,localhost:5002,localhost:5003,localhost:5004,localhost:5000

and then, send the 100 payment to the node0 node. At first, the client or wallet needs it's own secret seed. To generate secret seed, visit https://portal.willet.io .

$ simple-fba-wallet.py node0 SCQ2IRPN4OXFIZNZODN6JQF6O4F2Z3ODA4W27C2GQSVD5WK2KQNA6WKF GAFVNM4NQLCE2RLQLYHIOIZAUEDG4U7RTGRTVNMKFX6KF3QKXTW72ULP 100

GAFVNM4NQLCE2RLQLYHIOIZAUEDG4U7RTGRTVNMKFX6KF3QKXTW72ULP is the public address of the other account.

• Generating keypair
• Creating account