Stacking

Overview
Anyone can create a user interface for Stacking CityCoins, two examples being minecitycoins.com and syvitamining.com.
Stacking CityCoins happens by calling the contract function stack-tokens.
You cannot Stack in the currently active reward cycle, only for the next reward cycle.
e.g. if you select to Stack in a block height in reward cycle 1 then Stacking will begin in reward cycle 2.
A nominal transaction fee is required in order to send this transaction, paid in STX.
Details
The current reward cycle for a given block height can be found by calling get-reward-cycle in the core contract and supplying the block height.
Stacking statistics for a given cycle are available through get-stacking-stats-at-cycle, and individual account Stacking details are available through get-stacker-at-cycle.
Both functions for Stacking information also include a -or-default version that returns empty default values instead of some or none Clarity types.
To Stack CityCoins for a user with stack-tokens:
enter the amount of CityCoins to Stack
enter the number of reward cycles to Stack for
submit the transaction to the smart contract
Contract Functions
​API Ref: Stacking​
get-stacking-stats-at-cycle
Type: Read-only Function
Input: rewardCycle as uint
Returns: (some StackingStatsAtCycle) as a tuple or (none)
Returns the stacking stats at a given reward cycle, including:
amountUstx - total rewards from miners in uSTX
amountToken - total CityCoins Stacked
get-stacking-stats-at-cycle-or-default
Type: Read-only Function
Input: rewardCycle as uint
Returns: (some StackingStatsAtCycle) as a tuple, or defaults
Returns the same as get-stacking-stats-at-cycle above, except if no entry is found, returns the default structure of:
amountUstx: 0
amountToken: 0
get-stacker-at-cycle
Type: Read-only Function
Input: rewardCycle as uint and userId as uint
Returns: (some StackerAtCycle) as a tuple or (none)
Returns the stacking stats for a given user ID and reward cycle, including:
amountStacked - the total amount of CityCoins Stacked
toReturn - the total amount of CityCoins that can be reclaimed from the contract
get-stacker-at-cycle-or-default
Type: Read-only Function
Input: rewardCycle as uint and userId as uint
Returns: (some StackerAtCycle) as a tuple, or defaults
Returns the same as get-stacker-at-cycle above, except if no entry is found, returns the default structure of:
amountStacked: 0
toReturn: 0
get-reward-cycle
Type: Read-only Function
Input: stacksHeight as uint
Returns: (some rewardCycle) as uint or (none)
Returns the active reward cycle for a given block height.
stacking-active-at-cycle
Type: Read-only Function
Input: rewardCycle as uint
Returns: true or false
Returns a boolean value indicating if stacking is active at a given reward cycle, meaning a positive number of CityCoins are Stacked for that cycle.
get-first-stacks-block-in-reward-cycle
Type: Read-only Function
Input: rewardCycle as uint
Returns: firstBlockInCycle as uint
Returns the starting Stacks block height for a given reward cycle.
stack-tokens
Type: Public Function
Input: amountTokens as uint and lockPeriod as uint
Success: (ok true)
Errors:
ERR_CONTRACT_NOT_ACTIVATED u1005
ERR_STACKING_NOT_AVAILABLE u1015
ERR_CANNOT_STACK u1016
Stacking happens through calling the stack-tokens function in the contract, which accepts an amount of CityCoins to Stack in addition to a number of reward cycles to Stack them for.