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

SIP-010: Standard Trait Definition for Fungible Tokens

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 https://cdn.citycoins.co.

MiamiCoin (MIA) example:

{
  "name": "MiamiCoin",
  "description": "A CityCoin for Miami, ticker is MIA, Stack it to earn Stacks (STX)",
  "image": "https://cdn.citycoins.co/logos/miamicoin.png"
}

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.