Yoink
Play Yoink, an onchain capture-the-flag game on Base. Yoink the flag from the current holder to start your clock. The player with the most total yoinks holds the trophy.
Contract: 0x4bBFD120d9f352A0BEd7a014bd67913a2007a878 on Base (chain ID 8453)
Game Rules
- Yoink the flag - Call
yoink()to take the flag from the current holder - Cooldown - You must wait 10 minutes (600 seconds) between yoinks
- No self-yoink - You cannot yoink from yourself
- Accumulate time - While you hold the flag, your time score increases
- Compete for trophy - The player with the most total yoinks holds the trophy (token ID 2)
- Track yoinks - Your total yoink count is tracked separately from time
Contract Interface
RPC template:
curl -s -X POST https://mainnet.base.org -H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"0x4bBFD120d9f352A0BEd7a014bd67913a2007a878","data":"SELECTOR+PARAMS"},"latest"],"id":1}' | jq -r '.result'| Function | Selector | Params | Returns |
|---|---|---|---|
yoink() | 0x9846cd9e | - | (write) |
lastYoinkedBy() | 0xd4dbf9f4 | - | address |
lastYoinkedAt() | 0x6a99616f | - | uint256 timestamp |
totalYoinks() | 0xa5d0dadd | - | uint256 |
topYoinker() | 0x6a974e6e | - | address (trophy holder) |
mostYoinks() | 0xd2d7774a | - | uint256 (record) |
COOLDOWN() | 0xa2724a4d | - | uint256 (600) |
score(address) | 0x776f3843 | addr (32B padded) | (yoinks, time, lastYoinkedAt) |
balanceOf(address,uint256) | 0x00fdd58e | addr + tokenId | uint256 (FLAG_ID=1, TROPHY_ID=2) |
Encoding: Addresses are zero-padded to 32 bytes. score() returns 96 bytes (3 × uint256).
Yoinking
Use Bankr's arbitrary transaction feature:
{
"to": "0x4bBFD120d9f352A0BEd7a014bd67913a2007a878",
"data": "0x9846cd9e",
"value": "0",
"chainId": 8453
}Errors
| Error | Selector | Meaning |
|---|---|---|
SlowDown(uint256) | 0x58d6f4c6 | Cooldown not elapsed. Param = seconds remaining. |
Unauthorized() | 0x82b42900 | You already hold the flag. |
Cooldown check: current_time - lastYoinkedAt() >= 600
Workflow
- Query
lastYoinkedBy()andlastYoinkedAt()to check status/cooldown - Ensure cooldown elapsed (600s) and you're not current holder
- Submit yoink transaction via Bankr
- Verify with
lastYoinkedBy()orscore(address)
Resources
- Basescan: https://basescan.org/address/0x4bBFD120d9f352A0BEd7a014bd67913a2007a878 (ABI, events, source)
- Source Code: https://github.com/horsefacts/yoink-contracts