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

MiamiCoin (MIA) example:

  "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.

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