|
| 1 | +# SIP-010 Fungible Token Example |
| 2 | + |
| 3 | +A complete implementation of the SIP-010 standard for fungible tokens on Stacks. |
| 4 | + |
| 5 | +## Overview |
| 6 | + |
| 7 | +This example demonstrates how to create a fungible token that implements the [SIP-010 standard](https://github.com/stacksgov/sips/blob/main/sips/sip-010/sip-010-fungible-token-standard.md), making it compatible with wallets, exchanges, and other ecosystem tools. |
| 8 | + |
| 9 | +## Complete Contract |
| 10 | + |
| 11 | +```clarity |
| 12 | +;; SIP-010 Fungible Token Example |
| 13 | +;; A simple implementation of the SIP-010 standard |
| 14 | +
|
| 15 | +(impl-trait 'SP3FBR2AGK5H9QBDH3EEN6DF8EK8JY7RX8QJ5SVTE.sip-010-trait-ft-standard.sip-010-trait) |
| 16 | +
|
| 17 | +(define-fungible-token reward-token u1000000000) |
| 18 | +
|
| 19 | +(define-constant contract-owner tx-sender) |
| 20 | +(define-constant err-owner-only (err u100)) |
| 21 | +(define-constant err-not-token-owner (err u101)) |
| 22 | +
|
| 23 | +;; SIP-010 Functions |
| 24 | +
|
| 25 | +(define-public (transfer (amount uint) (sender principal) (recipient principal) (memo (optional (buff 34)))) |
| 26 | + (begin |
| 27 | + (asserts! (is-eq tx-sender sender) err-not-token-owner) |
| 28 | + (try! (ft-transfer? reward-token amount sender recipient)) |
| 29 | + (match memo to-print (print to-print) 0x) |
| 30 | + (ok true) |
| 31 | + ) |
| 32 | +) |
| 33 | +
|
| 34 | +(define-read-only (get-name) |
| 35 | + (ok "Reward Token") |
| 36 | +) |
| 37 | +
|
| 38 | +(define-read-only (get-symbol) |
| 39 | + (ok "RWD") |
| 40 | +) |
| 41 | +
|
| 42 | +(define-read-only (get-decimals) |
| 43 | + (ok u6) |
| 44 | +) |
| 45 | +
|
| 46 | +(define-read-only (get-balance (who principal)) |
| 47 | + (ok (ft-get-balance reward-token who)) |
| 48 | +) |
| 49 | +
|
| 50 | +(define-read-only (get-total-supply) |
| 51 | + (ok (ft-get-supply reward-token)) |
| 52 | +) |
| 53 | +
|
| 54 | +(define-read-only (get-token-uri) |
| 55 | + (ok (some u"https://example.com/token-metadata.json")) |
| 56 | +) |
| 57 | +
|
| 58 | +;; Mint function (only owner) |
| 59 | +(define-public (mint (amount uint) (recipient principal)) |
| 60 | + (begin |
| 61 | + (asserts! (is-eq tx-sender contract-owner) err-owner-only) |
| 62 | + (ft-mint? reward-token amount recipient) |
| 63 | + ) |
| 64 | +) |
| 65 | +``` |
| 66 | + |
| 67 | +## Key Features |
| 68 | + |
| 69 | +### 1. Trait Implementation |
| 70 | +The contract implements the SIP-010 trait, ensuring compatibility: |
| 71 | +```clarity |
| 72 | +(impl-trait 'SP3FBR2AGK5H9QBDH3EEN6DF8EK8JY7RX8QJ5SVTE.sip-010-trait-ft-standard.sip-010-trait) |
| 73 | +``` |
| 74 | + |
| 75 | +### 2. Token Transfer |
| 76 | +Allows users to transfer tokens with optional memo: |
| 77 | +```clarity |
| 78 | +(define-public (transfer (amount uint) (sender principal) (recipient principal) (memo (optional (buff 34)))) |
| 79 | + (begin |
| 80 | + (asserts! (is-eq tx-sender sender) err-not-token-owner) |
| 81 | + (try! (ft-transfer? reward-token amount sender recipient)) |
| 82 | + (match memo to-print (print to-print) 0x) |
| 83 | + (ok true) |
| 84 | + ) |
| 85 | +) |
| 86 | +``` |
| 87 | + |
| 88 | +### 3. Read-Only Functions |
| 89 | +Required metadata functions for token information: |
| 90 | +- `get-name`: Returns token name |
| 91 | +- `get-symbol`: Returns token symbol |
| 92 | +- `get-decimals`: Returns decimal places |
| 93 | +- `get-balance`: Returns balance for an address |
| 94 | +- `get-total-supply`: Returns total token supply |
| 95 | +- `get-token-uri`: Returns metadata URI |
| 96 | + |
| 97 | +### 4. Access Control |
| 98 | +Only the contract owner can mint new tokens: |
| 99 | +```clarity |
| 100 | +(define-public (mint (amount uint) (recipient principal)) |
| 101 | + (begin |
| 102 | + (asserts! (is-eq tx-sender contract-owner) err-owner-only) |
| 103 | + (ft-mint? reward-token amount recipient) |
| 104 | + ) |
| 105 | +) |
| 106 | +``` |
| 107 | + |
| 108 | +## Usage Examples |
| 109 | + |
| 110 | +### Deploying the Contract |
| 111 | +```bash |
| 112 | +clarinet contract deploy token |
| 113 | +``` |
| 114 | + |
| 115 | +### Minting Tokens |
| 116 | +```clarity |
| 117 | +(contract-call? .reward-token mint u1000000 'ST1PQHQKV0RJXZFY1DGX8MNSNYVE3VGZJSRTPGZGM) |
| 118 | +``` |
| 119 | + |
| 120 | +### Transferring Tokens |
| 121 | +```clarity |
| 122 | +(contract-call? .reward-token transfer |
| 123 | + u1000 |
| 124 | + tx-sender |
| 125 | + 'ST2CY5V39NHDPWSXMW9QDT3HC3GD6Q6XX4CFRK9AG |
| 126 | + none) |
| 127 | +``` |
| 128 | + |
| 129 | +### Checking Balance |
| 130 | +```clarity |
| 131 | +(contract-call? .reward-token get-balance tx-sender) |
| 132 | +``` |
| 133 | + |
| 134 | +## Customization |
| 135 | + |
| 136 | +You can customize this template by: |
| 137 | + |
| 138 | +1. **Changing token properties**: |
| 139 | + - Modify `get-name` for your token name |
| 140 | + - Modify `get-symbol` for your token symbol |
| 141 | + - Adjust `get-decimals` for precision |
| 142 | + |
| 143 | +2. **Adjusting supply**: |
| 144 | + - Change max supply in `define-fungible-token` |
| 145 | + |
| 146 | +3. **Adding features**: |
| 147 | + - Burn functionality |
| 148 | + - Pausable transfers |
| 149 | + - Allowance system |
| 150 | + |
| 151 | +## Testing |
| 152 | + |
| 153 | +Test your token with Clarinet: |
| 154 | + |
| 155 | +```toml |
| 156 | +# Clarinet.toml |
| 157 | +[contracts.reward-token] |
| 158 | +path = "contracts/reward-token.clar" |
| 159 | +``` |
| 160 | + |
| 161 | +Run tests: |
| 162 | +```bash |
| 163 | +clarinet test |
| 164 | +``` |
| 165 | + |
| 166 | +## Best Practices |
| 167 | + |
| 168 | +1. **Always validate sender**: Ensure `tx-sender` matches the `sender` parameter |
| 169 | +2. **Use error codes**: Define clear error codes for debugging |
| 170 | +3. **Implement all trait functions**: Required for SIP-010 compatibility |
| 171 | +4. **Add access control**: Protect sensitive functions like `mint` |
| 172 | +5. **Test thoroughly**: Test all functions before mainnet deployment |
| 173 | + |
| 174 | +## Resources |
| 175 | + |
| 176 | +- [SIP-010 Specification](https://github.com/stacksgov/sips/blob/main/sips/sip-010/sip-010-fungible-token-standard.md) |
| 177 | +- [Clarity Language Reference](https://docs.stacks.co/clarity) |
| 178 | +- [Fungible Tokens Guide](https://docs.stacks.co/write-smart-contracts/tokens) |
| 179 | + |
| 180 | +## License |
| 181 | + |
| 182 | +This example is provided as-is for educational purposes. |
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