10 Dec 2019
Registering stake pool
There are multiple components to be aware of when running a stake pool:
NodeId: it is the identifier within the blockchain protocol (wallet will delegate to your stake pool via this
- your VRF key pairs: this is the cryptographic material we will use to participate to the leader election;
- your KES key pairs: this is the cryptographic material we will use to sign the block with.
So in order to start your stake pool you will need to generate these objects.
VRF key pair
jcli key generate --type=Curve25519_2HashDH > stake_pool_vrf.prv
stake_pool_vrf.prv file now contains the VRF private key.
cat stake_pool_vrf.prv | jcli key to-public > stake_pool_vrf.pub
KES key pair
Similar to above:
jcli key generate --type=SumEd25519_12 > stake_pool_kes.prv
stake_pool_kes.prv now contains your KES private key
cat stake_pool_kes.prv | jcli key to-public > stake_pool_kes.pub
Choosing the Tax parameters
There are 3 values you can set to configure the stake pool's Tax:
tax-fixed: this is the fixed cut the stake pool will take from the total reward due to the stake pool;
tax-ratio: this is the percentage of the remaining value that will be taken from the total due
tax-limit: a value that can be set to limit the pool's Tax.
All of these values are optionals, if not set, they will be set to
0. This will mean no tax for the stake pool: rewards are all distributed to the delegators.
Let say you control a stake pool
SP, with 2 owners (
O2). During epoch 1,
SP has created some blocks and is entitled to receive
Before distributing the
10_000 among the delegators,
SP will take its Tax.
- we extract the
tax-fixed. If this is greater or equal to the total (
10_000) then we stop there, there is no more rewards to distribute.
- with what remains the
tax-ratioand checks the tax from the ratio is not greater than
- the total
SPrewards will then be distributed equally to the owners (O1 and O2). Note that if the
--reward-accountis set, the rewards for
SPare then distributed to that account and nothing to
|fixed of 1000||10000||1000||0/1||0||1000||500||500||9000|
|fixed + 10%||2000||1000||1/10||0||1100||550||550||900|
|fixed + 20% up to 150||2000||1000||1/5||150||1150||575||575||850|
--tax-limit <TAX_LIMIT> The maximum tax value the stake pool will take. This will set the maximum the stake pool value will reserve for themselves from the `--tax-ratio` (excluding `--tax-fixed`). --tax-ratio <TAX_RATIO> The percentage take of the stake pool. Once the `tax-fixed` has been take, this is the percentage the stake pool will take for themselves. [default: 0/1] --tax-fixed <TAX_VALUE> set the fixed value tax the stake pool will reserve from the reward For example, a stake pool may set this value to cover their fixed operation costs. [default: 0]
Creating a stake pool certificate
The certificate is what will be sent to the blockchain in order to register yourself to the other participants of the blockchain that you are a stake pool too.
jcli certificate new stake-pool-registration \ --kes-key $(cat stake_pool_kes.pub) \ --vrf-key $(cat stake_pool_vrf.pub) \ --start-validity 0 \ --management-threshold 1 \ --owner $(cat owner_key.pub) \ --operator $(cat operator_key.pub) \ --serial 1010101010 > stake_pool.cert
--operator flag is optional.
And now you can retrieve your stake pool id (
cat stake_pool.cert | jcli certificate get-stake-pool-id | tee stake_pool.id ea830e5d9647af89a5e9a4d4089e6e855891a533316adf4a42b7bf1372389b74
Submitting to a node
jcli transaction add-certificate command should be used to add a certificate before finalizing the transaction.
... jcli transaction add-certificate $(cat stake_pool.cert) --staging tx jcli transaction finalize CHANGE_ADDRESS --fee-constant 5 --fee-coefficient 2 --fee-certificate 2 --staging tx ... jcli transaction seal --staging tx jcli transaction auth --key owner_key.prv --staging tx ...
--fee-certificate flag indicates the cost of adding a certificate, used for computing the fees, it can be omitted if it is zero.
See 4.3 Transaction for more documentation on transaction creation.