Skills qrcoin

Interact with QR Coin auctions on Base. Use when the user wants to participate in qrcoin.fun QR code auctions — check auction status, view current bids, create new bids, or contribute to existing bids. QR Coin lets you bid to display URLs on QR codes; the highest bidder's URL gets encoded.

install

source · Clone the upstream repo

git clone https://github.com/BankrBot/skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/BankrBot/skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/qrcoin" ~/.claude/skills/bankrbot-skills-qrcoin && rm -rf "$T"

manifest: qrcoin/SKILL.md

source content

QR Coin Auction

Participate in QR Coin 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

Each auction runs for a fixed period (~24h)
Bidders submit URLs with USDC (6 decimals — 1 USDC = 1000000 units)
Creating a new bid costs ~11.11 USDC (createBidReserve)
Contributing to an existing bid costs ~1.00 USDC (contributeReserve)
Highest bid wins; winner's URL is encoded in the QR code
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.

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

# 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

# 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: