🗻 Metaphor

A confidential, automated RWA hub for institutions: bonds tokenized on ADI Chain, negotiated in Canton data rooms the rest of the market cannot see, paid on a Hedera schedule with no keeper, and reviewed by an AI on 0G that never signs.

🏅 Finalist — ADI Foundation, Open Project Submission ($287) · ETHDenver 2026

Video demo · Specification · Bounty compliance · Demo guide

Institutions that tokenize bonds on a public chain show their positions to the whole market, pay coupons from a cron job on a server, and run risk analysis in spreadsheets that never see the ledger. Metaphor gives each of those jobs to the chain built for it, behind a single dashboard: issuance and access control on ADI Chain, confidential negotiation on Canton, coupon payments scheduled by the Hedera network itself, and risk analysis on 0G Compute with a human approving every recommendation. Four chains, one interface.

🏅 Finalist on the ADI Foundation bounty at ETHDenver 2026, Denver, February 2026. One of the flagship Ethereum events of the year, with 186 projects submitted to its BUIDLathon. Three students from DeVinci Blockchain built Metaphor there for the New France Village track and four sponsor bounties at once (ADI Foundation, Canton Network, Hedera and 0G Labs), and it was named a finalist on ADI Foundation's $25,000 Open Project Submission bounty.

Table of contents

• How it works
• Four chains, one interface
• Architecture
• Deployed contracts
• What's live vs. simulated
• Getting started
• Tests
• Tech stack
• Repository structure
• Team
• License

How it works

The life of a tokenized bond, from issuance to coupon:

1. Issue on ADI Chain. An issuer mints an ERC-20 through RWATokenFactory, with the ISIN, coupon rate, maturity and issuer written on chain. A transfer only settles when both wallets are whitelisted, and a token can be fractionalized into sub-tokens.
2. Hold it in a vault. VaultManager groups tokens into vaults (create, deposit, withdraw, allocate) behind four on-chain roles, Admin, Issuer, Investor and Auditor, and an emergency pause.
3. Negotiate on Canton. The data room is a Daml contract. The owner sees everything, counterparties see the composition and propose trades, an auditor holds a separate AuditRight with aggregate figures only, and for everyone else the contract does not exist.
4. Pay the coupons on Hedera. CouponScheduler registers the bond, derives its payment dates and schedules each coupon from Solidity through the Schedule Service precompile at 0x16b: the network itself calls the payment on its date, with no keeper and no cron job. A payment is all or nothing: without enough liquidity it is marked failed, never paid in part. The issuer then distributes the coupon pro rata to holders through YieldDistributor, from a snapshot.
5. Review the risk on 0G. The AI engine sends the vault to 0G Compute and gets back a risk report validated against a schema: a global score, an analysis per position, stress tests and recommendations. Each recommendation waits for a human approval, and the AI has no signing authority.

Institutions come in as tenants: InstitutionRegistry gives each one its own isolated set of contracts (access control, token factory, vault manager), and registering an institution takes two admin approvals. Signing in is a wallet signature (EIP-191) exchanged for a 24-hour JWT whose roles are read on chain.

Four chains, one interface

Layer	Where	What runs there
Issuance and access	ADI Chain (99999), also on Sepolia	InstiVaultAccessControl (four roles, whitelist) · RWAToken · RWATokenFactory · VaultManager · InstitutionRegistry (white-label tenants, two approvals) · InstitutionDeployer
Confidentiality	Canton (Daml)	nine templates in three modules: ConfidentialVault (vault, invitation, access right, trade request, settlement), PrivateTrade (multi-round offers, agreement), AuditRight (invitation, aggregate-only view)
Automation	Hedera Testnet	CouponScheduler (payment dates, scheduling through IHRC755 and IHRC1215) · YieldDistributor (snapshot, pro-rata claims)
Intelligence	0G Compute	ai-engine: risk analyzer, strategy simulator and stress tests, reports validated with Zod, a deterministic mock as fallback

On Canton the visibility is enforced by the ledger, not hidden by the interface:

Owner (signatory)          full access: manage parties, trade, settle
Counterparty (observer)    sees the vault composition, proposes trades
Auditor                    separate AuditRight contract, aggregate data only
Everyone else              nothing: the contract does not exist for them

Three things the build had to get right:

• The Hedera sender. Inside the EVM, msg.sender is the ECDSA alias of the account, not the long-zero address returned by AccountId.toSolidityAddress(). Every script derives the owner from the public key; with the long-zero form, onlyOwner always reverts.
• Scheduling from Solidity. The coupons are scheduled by calling the 0x16b precompile directly from the contract, a pattern with no example in the Hedera documentation at the time.
• The contract size limit. InstitutionRegistry outgrew the EIP-170 bytecode limit, so deploying a tenant's contracts moved to the external InstitutionDeployer.

Architecture

                     Next.js dashboard (:3000)
               RainbowKit · wagmi · viem · 10 pages
                                 │
                                 │  EIP-191 sign-in, JWT bearer
                                 ▼
                        Express API (:3001)
             on-chain roles · RBAC · aggregated v1 API
        ┌────────────────┬───────┴───────┬────────────────┐
    ethers.js        ethers.js       JSON API         0G broker
        │                │               │                │
    ADI Chain         Hedera          Canton         0G Compute
     (99999)          Testnet          Daml           inference
   6 contracts      2 contracts     9 templates     risk reports

The backend is the only component that talks to the four networks: ethers.js for ADI Chain and for Hedera's JSON-RPC relay, the JSON API for the Daml ledger, and the 0G serving broker for inference. Its aggregated v1 API feeds the dashboard and falls back to demo data when a network is unreachable.

Deployed contracts

ADI Chain testnet (chain 99999, explorer) and Ethereum Sepolia (chain 11155111):

Contract	ADI Chain	Sepolia
InstiVaultAccessControl	0x8e7d4e14…dd656d	0x6ccfbc2c…f05043
RWATokenFactory	0x0ed29f8c…5d7d65	0xe6c7cccc…36921b
VaultManager	0x6b6449bd…c1534f	0xa162023b…6b8044
InstitutionRegistry	0xab3cbc56…3b1daf	0x442ec1e3…031002
InstitutionDeployer	0x6804fc93…66179b	0x531d24ca…1bb274

Hedera Testnet:

Contract	Hedera ID	EVM address
CouponScheduler	0.0.7996912	0x…007a05f0
YieldDistributor	0.0.7996914	0x…007a05f2

The twelve contracts were still deployed on 16 September 2026. The Daml package runs on a local Canton sandbox, set up as described in packages/contracts-canton.

What's live vs. simulated

• On chain: the ADI contracts on ADI Chain testnet and Sepolia, and CouponScheduler and YieldDistributor on Hedera Testnet, where CouponScheduler holds five registered bonds with their coupon dates computed on chain.
• Canton: the Daml contracts pass 28 Daml Script tests and run on a local sandbox. The deployment on Canton's Devnet L1 asked for by the bounty was not done.
• 0G: the engine calls 0G Compute when a provider is configured, and otherwise returns a deterministic mock report (ZG_USE_MOCK=true in .env.example).
• Dashboard: the aggregated API reads the contracts and falls back to demo data when a network is unreachable or empty, so parts of the dashboard can show demo figures.
• No hosted deployment: the product is shown in the video demo and runs locally with the steps below.

Getting started

Prerequisites: Node 20+, pnpm 9+ and Foundry. The Canton package also needs Java 17+ and DPM with the Daml SDK 3.4.11, see packages/contracts-canton.

git clone --recurse-submodules https://github.com/DVB-ANS/Metaphor.git
cd Metaphor
pnpm install

cp .env.example .env          # RPC endpoints, keys and deployed addresses, for every package
set -a && source .env && set +a

pnpm dev:backend              # Express API on http://localhost:3001
pnpm dev:frontend             # Next.js on http://localhost:3000

With DEV_MODE=true, POST /api/auth/dev-login returns a JWT holding the four roles, the quickest way to open every page locally.

To deploy your own contracts, from the same shell:

# ADI Chain, or Sepolia with ADI_RPC_URL pointing at a Sepolia RPC
cd packages/contracts-adi
forge script script/Deploy.s.sol --rpc-url "$ADI_RPC_URL" --broadcast    # signs with ADI_PRIVATE_KEY
cd ../..

# Hedera Testnet, with HEDERA_OPERATOR_ID and HEDERA_OPERATOR_KEY
pnpm --filter contracts-hedera run deploy
pnpm --filter contracts-hedera run register-bond
pnpm --filter contracts-hedera run schedule

# Canton, on a local sandbox (ledger API on 6865, JSON API on 7575)
pnpm build:canton
pnpm --filter contracts-canton run sandbox

Tests

Package	Framework	Tests
contracts-adi	Forge	111
contracts-hedera	Forge	74
contracts-canton	Daml Script	28
ai-engine	Vitest	21

pnpm test          # the four suites
pnpm test:adi      # or one at a time: test:hedera, test:canton, test:ai

The Forge and Vitest suites were run again on 16 September 2026, 206 tests passing; the Daml suite needs DPM.

Tech stack

Layer	Technology
ADI contracts	Solidity 0.8.24, Foundry, OpenZeppelin 5.5
Hedera contracts	Solidity 0.8.24, Foundry, the Schedule Service system contract (IHRC755, IHRC1215), Hedera SDK
Canton contracts	Daml, SDK 3.4.11, DPM
AI engine	0G Compute (@0glabs/0g-serving-broker), OpenAI-compatible client, Zod
Backend	Express 4, ethers 6, jsonwebtoken, TypeScript (ESM)
Frontend	Next.js 16, React 19, Tailwind CSS 4, shadcn/ui, RainbowKit, wagmi, viem, Recharts, GSAP, Motion
Tooling	pnpm workspaces, Forge, Vitest, Prettier

Repository structure

packages/
  contracts-adi/          Foundry: roles, RWA tokens, vaults, white-label registry (ADI Chain, Sepolia)
  contracts-hedera/       Foundry and Hedera SDK: coupon scheduling, yield distribution, deploy scripts
  contracts-canton/       Daml: confidential vaults, private trades, audit rights, sandbox scripts
  ai-engine/              0G Compute client, risk analyzer, strategy simulator, prompts, mock
  backend/                Express API: wallet sign-in, RBAC, per-chain routes, aggregated v1 API
  frontend/               Next.js dashboard, 10 pages
docs/
  SPEC.md                 specification: features, data flows, API endpoints, constraints
  BOUNTY_COMPLIANCE.md    every bounty requirement, with its evidence
  DEMO_GUIDE.md           the demo walkthrough, with the commands that check each step on chain

Team

Three students from DeVinci Blockchain, Paris, at ETHDenver 2026.

	Role
Sofiane Ben Taleb	frontend and backend	GitHub · LinkedIn
Noé Wales	Solidity contracts on ADI Chain and Hedera, backend integration	GitHub · LinkedIn
Armand Séchon	Daml contracts on Canton, AI engine on 0G	GitHub · LinkedIn

License

MIT © 2026 Sofiane Ben Taleb, Noé Wales and Armand Séchon. The Hedera system-contract interfaces vendored in packages/contracts-hedera/contracts/hedera-deps/ keep their Apache-2.0 license.

_{Built for ETHDenver 2026 · New France Village track · ADI Foundation, Canton Network, Hedera and 0G Labs bounties}