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

1. Yoink the flag - Call yoink() to take the flag from the current holder
2. Cooldown - You must wait 10 minutes (600 seconds) between yoinks
3. No self-yoink - You cannot yoink from yourself
4. Accumulate time - While you hold the flag, your time score increases
5. Compete for trophy - The player with the most total yoinks holds the trophy (token ID 2)
6. 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'

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

Cooldown check: current_time - lastYoinkedAt() >= 600

Workflow

• Query lastYoinkedBy() and lastYoinkedAt() to check status/cooldown
• Ensure cooldown elapsed (600s) and you're not current holder
• Submit yoink transaction via Bankr
• Verify with lastYoinkedBy() or score(address)

Resources

• Basescan: https://basescan.org/address/0x4bBFD120d9f352A0BEd7a014bd67913a2007a878 (ABI, events, source)
• Source Code: https://github.com/horsefacts/yoink-contracts