Live on Canton Sandbox · ADI Anvil · Hedera Testnet

BlindBid

Private Markets, Public Trust

A B2B marketplace where bidders submit confidential offers, auction logic runs privately on Canton, settlement is gasless on ADI, and a Hedera audit trail proves everything.

Launch Live DemoPrivacy ExplorerAudit Trail
Canton NetworkDamlADI · ERC-4337Hedera HCSHiero CLI

Workflow

How BlindBid Works

Five stages, three blockchains, zero data leakage.

STEP 1Canton + Daml

Create Private Auction

Seller deploys a Daml Auction contract on Canton with scoring weights and invited bidders.

STEP 2Canton Privacy

Submit Sealed Bids

Each bidder submits price, delivery SLA, penalties, warranty. Canton ensures bidders only see their own bid.

STEP 3Daml Choices

Private Scoring & Award

Multi-criteria scoring happens privately. The award proof shows criteria used — never actual bid values.

STEP 4ADI · ERC-4337

Gasless Settlement on ADI

Winner pays through ADI escrow with zero gas cost via ERC-4337 paymasters.

STEP 5Hedera HCS

Public Audit on Hedera

Hash commitments published to HCS. Anyone verifies timing — nobody reverses into business data.

Canton Network

Party-Based Privacy

Enforced by the ledger, not application logic. Each party sees only what they're authorized to.

👔

Seller

CAN SEE

All bids & terms
Full score breakdown
All reputations
Escrow status
🏭

Bidder A

CAN SEE

Own bid only
Own total score
Auction stage
Award criteria

HIDDEN

Other bids
Score breakdown
Weights
🏗️

Bidder B

CAN SEE

Own bid only
Own total score
Auction stage
Award criteria

HIDDEN

Other bids
Score breakdown
Weights
🔍

Auditor

CAN SEE

Auction metadata
Winner identity
Award proof
Conditions

HIDDEN

Bid values
Score details
Exact weights
Explore live party views

Bounties

Sponsor Tracks

Every bounty met with real, working implementations.

Canton Network

· Privacy-First dApp
$8,000 · 3 winners

Canton is the only blockchain where privacy is protocol-level. In B2B markets, revealing bid details destroys leverage.

Full Daml contracts: Auction, SealedBid, ScoredBid, AwardedAuction, Reputation
Real Canton Sandbox with compiled .dar
Party-based visibility enforced by ledger
Private scoring + explainable award proofs
JSON API integration — every call goes through Canton

ADI Foundation

· Paymaster Devtools
Paymaster Track

Bidders shouldn't need crypto to participate. ERC-4337 paymasters enable zero-gas onboarding.

BlindBidNativePaymaster with sponsor signature validation
BlindBidERC20Paymaster for token gas payments
Allowlist targets/selectors + rate limits + expiry
Demo failure cases: expired, invalid sig, bad selector
E2E tests with tx hashes, account addresses, balances

Hedera

· Hiero CLI Plugin
CLI Plugin Track

Hash commitments on HCS prove fairness without leaking private data.

Custom plugin: auctionlog publish, verify, export, list
Real HCS topic creation on Hedera testnet
Commitment = hash(auctionId + stage + cantonTxId + adiTxHash + ts + nonce)
Timeline verification + JSON/CSV export
Zod schema validation on all I/O

ADI Foundation

· Merchant Payments
Merchant Track

Real procurement needs multi-currency settlement — USD/AED listed, token settled.

Merchant registration + preferred currency
Signed fiat-to-token quotes with slippage & expiry
EIP-681 QR code + WalletConnect support
Checkout sessions with payment status tracking
BlindBidEscrow: deposit, release, refund, dispute, resolve

Stack

Architecture

Three blockchains, one seamless experience.

FrontendNext.js + Framer Motion + Tailwind
Backend APIExpress.js + TypeScript + Ethers.js
Canton SandboxDaml Contracts + JSON API + Privacy
ADI ChainERC-4337 · Paymasters · Escrow · Anvil
Hedera TestnetHCS Topics · Audit Commitments

See It Live

Every auction, bid, and score runs on real Canton, ADI, and Hedera. No mocks. All verifiable.

Launch Live Demo