qrcoin

# QR Coin Auction Participate in [QR Coin](https://qrcoin.fun) auctions on Base blockchain. QR Coin lets you bid to display URLs on QR codes — the highest bidder's URL gets encoded when the auction ends. ## Contracts (Base Mainnet) | Contract | Address | |----------|---------| | QR Auction | `0x7309779122069EFa06ef71a45AE0DB55A259A176` | | USDC | `0x833589fCD6eDb6E08f4c7c32D4f71b54bdA02913` | ## How It Works 1. Each auction runs for a fixed period (~24h) 2. Bidders submit URLs with USDC (6 decimals — 1 USDC = 1000000 units) 3. Creating a new bid costs ~11.11 USDC (createBidReserve) 4. Contributing to an existing bid costs ~1.00 USDC (contributeReserve) 5. Highest bid wins; winner's URL is encoded in the QR code 6. Losers get refunded; winners receive QR tokens ## Auction Status Queries > **Note**: The examples below use `https://mainnet.base.org` (public RPC). You can substitute your own RPC endpoint if preferred. ### Get Current Token ID Always query this first to get the active auction ID before bidding. ```bash curl -s -X POST https://mainnet.base.org \ -H "Content-Type: application/json" \ -d '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"0x7309779122069EFa06ef71a45AE0DB55A259A176","data":"0x7d9f6db5"},"latest"],"id":1}' \ | jq -r '.result' | xargs printf "%d\n" ``` ### Get Auction End Time ```bash # First get the current token ID, then use it here TOKEN_ID=329 # Replace with result from currentTokenId() TOKEN_ID_HEX=$(printf '%064x' $TOKEN_ID) curl -s -X POST https://mainnet.base.org \ -H "Content-Type: application/json" \ -d '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"0x7309779122069EFa06ef71a45AE0DB55A259A176","data":"0xa4d0a17e'"$TOKEN_ID_HEX"'"},"latest"],"id":1}' \ | jq -r '.result' | xargs printf "%d\n" ``` ### Get Reserve Prices ```bash # Create bid reserve (~11.11 USDC) curl -s -X POST https://mainnet.base.org \ -H "Content-Type: application/json" \ -d '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"0x7309779122069EFa06ef71a45AE0DB55A259A176","data":"0x5b3bec22"},"latest"],"id":1}' \ | jq -r '.result' | xargs printf "%d\n" | awk '{print $1/1000000 " USDC"}' # Contribute reserve (~1.00 USDC) curl -s -X POST https://mainnet.base.org \ -H "Content-Type: application/json" \ -d '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"0x7309779122069EFa06ef71a45AE0DB55A259A176","data":"0xda5a5cf3"},"latest"],"id":1}' \ | jq -r '.result' | xargs printf "%d\n" | awk '{print $1/1000000 " USDC"}' ``` ## Transactions via Bankr QR Coin auctions require USDC transactions on Base. Use Bankr to execute these — Bankr handles: - Function signature parsing and parameter encoding - Gas estimation - Transaction signing and submission - Confirmation monitoring ### Step 1: Approve USDC (One-Time) Before bidding, approve the auction contract to spend USDC: ``` Approve 50 USDC to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base ``` ### Step 2: Create a New Bid To start a new bid for your URL: **Function**: `createBid(uint256 tokenId, string url, string name)` **Contract**: `0x7309779122069EFa06ef71a45AE0DB55A259A176` **Cost**: ~11.11 USDC > **Important**: Always query `currentTokenId()` first to get the active auction ID. Example prompt for Bankr: ``` Send transaction to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base calling createBid(329, "https://example.com", "MyName") ``` ### Step 3: Contribute to Existing Bid To add funds to an existing URL's bid: **Function**: `contributeToBid(uint256 tokenId, string url, string name)` **Contract**: `0x7309779122069EFa06ef71a45AE0DB55A259A176` **Cost**: ~1.00 USDC per contribution Example prompt for Bankr: ``` Send transaction to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base calling contributeToBid(329, "https://grokipedia.com/page/debtreliefbot", "MerkleMoltBot") ``` ## Function Selectors | Function | Selector | Parameters | |----------|----------|------------| | `currentTokenId()` | `0x7d9f6db5` | — | | `auctionEndTime(uint256)` | `0xa4d0a17e` | tokenId | | `createBidReserve()` | `0x5b3bec22` | — | | `contributeReserve()` | `0xda5a5cf3` | — | | `createBid(uint256,string,string)` | `0xf7842286` | tokenId, url, name | | `contributeToBid(uint256,string,string)` | `0x7ce28d02` | tokenId, url, name | | `approve(address,uint256)` | `0x095ea7b3` | spender, amount | ## Error Codes | Error | Meaning | Solution | |-------|---------|----------| | `RESERVE_PRICE_NOT_MET` | Bid amount below minimum | Check reserve prices | | `URL_ALREADY_HAS_BID` | URL already has a bid | Use `contributeToBid` instead | | `BID_NOT_FOUND` | URL doesn't have existing bid | Use `createBid` instead | | `AUCTION_OVER` | Current auction has ended | Wait for next auction | | `AUCTION_NOT_STARTED` | Auction hasn't begun | Wait for auction to start | | `INSUFFICIENT_ALLOWANCE` | USDC not approved | Approve USDC first | ## Typical Workflow 1. **Query `currentTokenId()`** — Get the active auction ID 2. **Check auction status** — Verify time remaining 3. **Approve USDC** — One-time approval for the auction contract 4. **Decide action**: - **New URL**: Use `createBid` (~11.11 USDC) - **Support existing URL**: Use `contributeToBid` (~1.00 USDC) 5. **Monitor** — Watch for outbids and contribute more if needed 6. **Claim** — Winners receive QR tokens; losers get refunds ## Links - **Platform**: https://qrcoin.fun - **Auction Contract**: [BaseScan](https://basescan.org/address/0x7309779122069EFa06ef71a45AE0DB55A259A176) - **USDC on Base**: [BaseScan](https://basescan.org/token/0x833589fCD6eDb6E08f4c7c32D4f71b54bdA02913) ## Tips - **Start small**: Contribute to existing bids (~1 USDC) to learn the flow - **Check timing**: Auctions have fixed end times; plan accordingly - **Monitor bids**: Others can outbid you; watch the auction - **Use Bankr**: Let Bankr handle transaction signing and execution - **Specify Base**: Always include "on Base" when using Bankr --- **💡 Pro Tip**: Contributing to an existing bid is cheaper than creating a new one. Check if someone already bid for your URL before creating a new bid.