QR Auction Bidder

Bid on $QR daily auctions. Each auction lets you bid with USDC to win a QR code that points to your chosen URL for 24 hours.

Overview

$QR runs continuous 24-hour auctions on Base mainnet. The highest bid wins, and the winning URL is displayed on a real QR code. Losing bidders are refunded automatically.

• Website: https://qrcoin.fun
• Network: Base mainnet (chain ID 8453)
• Currency: USDC (6 decimals)
• Community: m/qr on moltbook.com
• Transaction execution: Uses Bankr — install the bankr skill from https://github.com/BankrBot/moltbot-skills

Contract Addresses

Minimum Bids

How Auctions Work

1. A new auction starts automatically after the previous one settles
2. Each auction has a tokenId, startTime, and endTime (typically 24 hours)
3. Bidders call createBid() to bid on a URL, or contributeToBid() to add USDC to an existing URL's bid
4. The highest total bid when time expires wins
5. If the leading URL changes in the last 5 minutes, the auction extends by 5 more minutes (up to 3 hours max beyond the scheduled end). Note: contributing to the already-winning URL does NOT trigger an extension.
6. After the auction ends, it's settled and losing bidders are refunded

Prerequisites

This skill uses Bankr for on-chain transaction execution. Install the bankr skill first:

https://github.com/BankrBot/moltbot-skills

Bankr handles wallet creation, USDC approvals, transaction signing, gas estimation, and confirmation. No private keys or wallet setup needed.

Check Auction Status

Query the current auction state via RPC:

# Get current auction state (tokenId, highestBid, startTime, endTime, settled)
curl -s -X POST https://mainnet.base.org \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"0x7309779122069EFa06ef71a45AE0DB55A259A176","data":"0xe4b8f0de"},"latest"],"id":1}' \
  | jq -r '.result'

The auction() function (selector 0xe4b8f0de) returns the full auction state including tokenId, highestBid, startTime, endTime, settled, and qrMetadata.

# Get number of bids in current auction
curl -s -X POST https://mainnet.base.org \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"0x7309779122069EFa06ef71a45AE0DB55A259A176","data":"0x91a3823f"},"latest"],"id":1}' \
  | jq -r '.result' | xargs printf "%d\n"

# Get create bid reserve price (should return 11110000 = 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":"0x4b6014f6"},"latest"],"id":1}' \
  | jq -r '.result' | xargs printf "%d\n"

Bidding with Bankr

Step 1: Approve USDC

Before bidding, approve the auction contract to spend your USDC. The contract takes your full allowance (up to your balance) as the bid amount, so set approval to exactly what you want to bid.

Approve 15 USDC to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base

Or via Bankr script:

scripts/bankr.sh "Approve 15 USDC to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base"

Step 2: Create a New Bid

Use createBid when no bid exists yet for your URL. Always query the current tokenId from auction() first.

Function: createBid(uint256 _tokenId, string _urlString, string _name)

Send transaction to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base calling createBid(329, "https://your-url.com", "YourName")

Or via Bankr script:

scripts/bankr.sh 'Send transaction to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base calling createBid(329, "https://your-url.com", "YourName")'

Important: Replace 329 with the actual current tokenId. Using a wrong token ID reverts with INVALID_TOKEN_ID.

Step 3: Contribute to an Existing Bid

Use contributeToBid to add USDC to a URL that already has a bid:

Function: contributeToBid(uint256 _tokenId, string _urlString, string _name)

Send transaction to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base calling contributeToBid(329, "https://existing-url.com", "YourName")

Or via Bankr script:

scripts/bankr.sh 'Send transaction to 0x7309779122069EFa06ef71a45AE0DB55A259A176 on Base calling contributeToBid(329, "https://existing-url.com", "YourName")'

Decide: createBid vs contributeToBid

• If your URL has no existing bid → use createBid (minimum 11.11 USDC)
• If your URL already has a bid → use contributeToBid (minimum 1.00 USDC)
• Calling createBid with a URL that already has a bid reverts with URL_ALREADY_HAS_BID
• Calling contributeToBid with a URL that has no bid reverts with BID_NOT_FOUND

Auction Timing

Important Notes

• USDC is real money. Bids use real USDC on Base mainnet. Only bid what you can afford to lose.
• Losing bids are refunded after the auction settles, but there may be a delay during batch processing.
• The contract takes your full allowance (up to your balance). Set your USDC approval to exactly your intended bid amount.
• URL must be unique per auction. If someone already bid on your URL, use contributeToBid. Calling createBid with a taken URL will revert with URL_ALREADY_HAS_BID.
• Token ID must match. Always read the current tokenId from auction() before bidding. Using a wrong token ID reverts with INVALID_TOKEN_ID.

Error Codes

ABI Reference

The full QRAuctionV5 ABI is available at references/QRAuctionV5.abi.json in this skill package.

Key functions:

Key events:

Typical Workflow

1. Check auction status — Query auction() for current tokenId and time remaining
2. Check existing bids — Query getAllBids() or getBid(url) to see what's already bid
3. Approve USDC via Bankr — Set allowance to exactly your intended bid amount
4. Place bid via Bankr — createBid for a new URL or contributeToBid for an existing one
5. Monitor — Watch for outbids and contribute more if needed
6. Settlement — Losing bids are refunded automatically after the auction settles

Links

• Platform: https://qrcoin.fun
• About / Docs: https://qrcoin.fun/about
• Auction Contract: https://basescan.org/address/0x7309779122069EFa06ef71a45AE0DB55A259A176
• Bankr skill: https://github.com/BankrBot/moltbot-skills
• Community: m/qr on moltbook.com