Supporting CityCoins

Interacting with the CityCoins protocol.

CityCoins Contracts

Each CityCoin is defined by a set of contracts for that city, including core, token, and auth.
The Contracts page lists the currently deployed CityCoins contracts with links to their on-chain source. The GitHub repo is where the contracts are stored and updated before deployment.

SIP-010 Standard

Clarity, has built-in language primitives to define and use fungible tokens. Although those primitives exists, there is value in defining a common interface (known in Clarity as a "trait") that allows different smart contracts to interoperate with fungible token contracts in a reusable way. This SIP defines that trait.
SIP-010 includes function definitions for:
  • transfer
  • name (human-readable)
  • symbol (ticker)
  • decimals (CityCoins have 6)
  • balance
  • total supply
  • token URI (externally hosted metadata)

Send-Many Function

In addition to SIP-010, all CityCoins token contracts implement an additional citycoin-token trait that defines:
  • activation
  • set token URI
  • mint
  • burn
  • send-many
The send-many function allows for sending to a list of up to 200 recipients in a single transaction.
The list must contain at least one entry with the following values:
  • to: principal
  • amount: uint
  • memo: optional buff 34

Token Metadata

Metadata for CityCoins are stored in a CDN available at
"name": "MiamiCoin",
"description": "A CityCoin for Miami, ticker is MIA, Stack it to earn Stacks (STX)",
"image": ""

Brand Resources

More information on brand assets and guidelines for CityCoins can be found in the CityCoins Resources section.

Stacking CityCoins

CityCoins follow a similar protocol to Stacking STX with a few key differences.
In the Stacks blockchain, 100% of what Stacks miners spend in BTC is transferred to Stackers.
In the CityCoins protocol, 30% of what CityCoin miners spend in STX is transferred to the custodied city wallet, and the remaining 70% is transferred to Stackers.
  • Stacked CityCoins are transferred to the contract for the duration of the cycles
    • STX rewards for each cycle can be claimed after the cycle ends
    • Stacked CityCoins can be reclaimed after the final cycle ends
  • Stacking rewards are distributed proportionately to the amount stacked, not in reward slots
  • Reward cycles are also 2,100 Stacks blocks in length, but the maximum is 32 cycles
Additional common questions and answers can be found in the Stacking Documentation.