Combinatorial Auction Bid Submission Tool

WHAT IT DOES

Combinatorial Auction Bid Submission Tool enables bidders to submit bids for bundles of items in combinatorial auctions, where bidders can express preferences for combinations of items rather than individual items. The tool reads the auction contract address, available item bundles, current bid status, auction start/end times, and your token balances. You specify which items you want in your bundle and your bid price—the tool submits the bid as a single transaction, approving token spend first if needed. It also displays all your active bids, allowing you to track which bundles you've bid on and withdraw bids if needed. This is ideal for spectrum auctions, procurement auctions, or any scenario where items have complementary value.

HOW TO USE

Connect your wallet and select your network. Enter the combinatorial auction contract address and the bid currency token address. Specify the item IDs you want to bid on as a comma-separated list (e.g., 1,2,3 for a bundle of items 1, 2, and 3). Enter your bid price in the auction's currency. Click "Submit bid" to approve token spend and submit your combinatorial bid. The tool automatically checks your token allowance and prompts for approval if needed. Use "Refresh status" to view all your active bids and the current auction status. To withdraw a bid, click "Withdraw bid" to remove your most recent active bid and recover your funds.

THE REAL MECHANISM — BUNDLED BID SUBMISSION WITH ALLOWANCE MANAGEMENT

Unlike simple single-item auctions, combinatorial auctions allow bidders to specify values for bundles, capturing complementarities between items. The tool constructs a bid transaction that includes an array of item IDs and a bid amount. The auction contract verifies that all items in the bundle are valid and available, that the bid amount meets any minimum increment, and that the bidder has sufficient allowance to cover the bid. The tool performs a pre-flight allowance check using the token's allowance function, and if insufficient, automatically triggers an approval transaction for the exact bid amount—never an unlimited approval. The bid is then submitted via the contract's submitBid function, which records the bidder, item bundle, and bid amount. The contract stores bids in a mapping, and the tool retrieves user bids using getBidderBids, which returns an array of bid indices. Each bid can be withdrawn using withdrawBid before the auction ends, returning the full bid amount. All arithmetic uses ethers.js BigNumber with the token's decimal precision. The tool uses receipt.effectiveGasPrice for accurate cost reporting and validates that the auction is active before allowing submissions.

WHAT IT CANNOT SEE

Cannot verify off-chain item valuations—this tool has no visibility into the actual value of items or whether a bid price is reasonable. It cannot ensure bidder rationality—bidders may submit bids that exceed their true valuation. It cannot predict winner determination outcomes—the combinatorial winner determination problem is computationally complex and depends on all submitted bids. It cannot detect if the auction contract contains vulnerabilities or collusion risks—the tool does not audit the auction logic or verify its implementation. It cannot prevent bid shading, bid manipulation, or other strategic behaviors.

PLEASE NOTE — EVM CHAINS ONLY

This tool exclusively supports EVM-compatible chains where ethers.js can connect via standard JSON-RPC. It does not support non-EVM chains such as Solana, Tron, Starknet, SUI, TON, Aptos, Bitcoin, Cosmos, or XRP. The auction contract must implement the specific interface expected by this tool (submitBid, withdrawBid, getBid, getBidCount, getBidderBids, getAuctionInfo, getItemCount). Always test with small amounts on a testnet before bidding on mainnet. This tool is a bid submission interface, not a financial advisor or valuation expert.