WaffleFinance

Non-custodial cross-chain atomic swap — Ethereum · Stellar · Solana
No validator set. No attester. No admin escape hatch.

Sepolia Contract · Stellar Testnet · CI

What it is

WaffleFinance locks funds in Hash Time-Lock Contracts (HTLCs) on each chain simultaneously. Settlement is a sha256 preimage reveal — not a multisig, not an attester signature.

If anything fails — coordinator down, resolver offline, RPC unavailable, frontend unreachable — locked funds either settle to the beneficiary or refund permissionlessly to the user. There is no state where funds are stuck under operator control.

Status: Live on testnet (Sepolia + Stellar testnet). Solana support is live in simulation mode — full settlement activates once the Anchor HTLC program is deployed on devnet. Mainnet gated until independent audit (Q1 2027).

Supported chains

Chain	Asset	Status
Ethereum (Sepolia)	ETH	✅ Live
Stellar	XLM	✅ Live
Solana	SOL	🟡 Simulation mode (Anchor program pending deployment)

How it works

User locks ETH (24h timelock)       →    Resolver locks XLM/SOL (12h timelock)
                                                       ↓
                                          User claims XLM/SOL, revealing secret
                                                       ↓
Resolver claims ETH using secret    ←    Secret is now public on-chain

Both legs settle, or both legs refund. The 12h vs 24h timelock gap ensures the resolver's destination refund always expires before the user's source — so neither party can ever be stuck.

Trust model

Funds move under exactly two conditions:

A caller submits a preimage where sha256(preimage) == hashlock before timelock — funds go to beneficiary
timelock has expired — anyone calls refundOrder and funds return to refundAddress (always the original user)

Robust native-ETH payout. A beneficiary / refundAddress that is a smart contract may revert on receipt or exhaust the bounded gas stipend. Rather than letting that block a settlement backed by a valid preimage or an expired timelock, HTLCEscrow attempts a direct push and, if it fails, credits the amount to the recipient's pull-payment balance instead of reverting. The claim/refund still finalises (the preimage is revealed on-chain either way), and the recipient — and only that recipient — recovers the funds permissionlessly via withdraw(). This adds no custodial surface: credited funds are never pooled or operator-movable, and withdraw() can only return a caller's own balance, never locked order funds.

The coordinator is a metadata service that never signs transactions touching user funds. Resolvers stake into ResolverRegistry; misbehaviour is slashable on-chain.

Attack vector	Validator-set bridge	WaffleFinance
Compromise off-chain signers	Funds lost	No effect — no signers
Compromise first-party attester	Funds lost	No effect — no attesters
Break sha256	Safe	Funds at risk (breaks all of crypto)
Compromise chain consensus	Funds at risk	Funds at risk (inherited)

Deployed contracts (testnet)

Contract	Chain	Address
`HTLCEscrow`	Sepolia	`0xb352339BEb…988bB178`
`ResolverRegistry`	Sepolia	`0x7D9ce70Aa4…1B6D1D99`
`wafflefinance-htlc`	Stellar testnet	`CDIKSJKV…CTA6JK`
`wafflefinance-resolver-registry`	Stellar testnet	`CBSR7Z4M…Z4WGF`
Anchor HTLC	Solana devnet	Pending deployment

Refund layers

Four independent recovery mechanisms — each a backstop for the previous one.

Layer	Trigger	Latency
On-chain HTLC refund	`timelock` expires; anyone calls `refundOrder`	≤ 24h
Frontend refund dialog	"Refund" button in transaction history	User-driven
Automatic refund	Destination leg fails mid-request; relayer refunds inline	< 30s
Background watchdog	Swap pending > 5 min; background scanner fires	< 6 min

Even with the coordinator, relayer, and frontend all offline, layer 1 alone is sufficient — the user calls refundOrder directly from any wallet.

Repository layout

contracts/          Solidity — HTLCEscrow + ResolverRegistry (Ethereum)
soroban/            Rust — Soroban HTLC + ResolverRegistry (Stellar)

packages/
  sdk/              @wafflefinance/sdk — shared TS types, asset mappings,
                    state machine, Solana + Stellar + Ethereum HTLC clients

coordinator/        Order book service (SQLite/Postgres, REST, never holds keys)
  src/
    listeners/      Ethereum + Soroban + Solana event listeners
    services/       OrderService, SecretService, QuoteService
    persistence/    Schema, migrations, repository
    server/         Express routes (/orders, /quotes, /secrets, /metrics)
    state-machine/  Shared order state machine
  migrations/
    001_initial.sql     Base schema
    002_solana_support.sql  Adds solana to Chain/Direction constraints

relayer/            Bridge relay service
  src/
    listeners/      Block polling, contract event poller
    services/       Gas tracker, refund watchdog, XLM refund, recovery

resolver/           Open-source resolver runner + Docker image
frontend/           React + Vite dApp (Ethereum · Stellar · Solana)
e2e/                Cross-chain differential test harness

Quick start

Dev container (recommended): open the repo in VS Code with the Dev Containers extension. VS Code will prompt you to reopen in the container — it installs Node 22, pnpm, Rust, stellar-cli, and Foundry automatically.

Native setup — requirements: Node 22.5+, pnpm 8+, Rust stable + wasm32-unknown-unknown target, stellar-cli, Foundry.

git clone https://github.com/Waffle-finance/waffle-finance-core
cd waffle-finance-core
pnpm install
cp env.example .env          # fill in RPC URLs and private keys

# Build shared SDK (required before anything else)
pnpm --filter @wafflefinance/sdk build

# Compile + test Solidity contracts
pnpm --filter @wafflefinance/contracts exec hardhat test

# Test Soroban contracts
cd soroban && cargo test && cd ..

# Start coordinator
pnpm --filter @wafflefinance/coordinator dev

# Seed with demo data for local development (optional)
pnpm --filter @wafflefinance/coordinator seed-demo

# Start frontend
pnpm --filter @wafflefinance/frontend dev

See docs/DEVELOPMENT.md for per-package commands, PostgreSQL setup, Stellar contract deployment, and troubleshooting notes.

See docs/OPERATIONS.md for deployment checklists, incident response runbooks, and monitoring guidance.

See docs/TECHNICAL_DEBT.md for the service-level technical debt register and roadmap — architectural gaps, known limitations, and planned improvements across all services.

Wallet support

Wallet	Chain	Hook
MetaMask	Ethereum	`window.ethereum`
Freighter	Stellar	`useFreighter()`
Phantom	Solana	`useSolanaWallet()`

All three wallets can be connected simultaneously from the wallet menu. The bridge form automatically selects the correct wallets based on the chosen route.

Solana integration

The Solana leg is fully wired end-to-end:

SDK — SolanaHTLCClient in packages/sdk/src/solana/ handles createOrder, claimOrder, refundOrder. Runs in simulation mode until the Anchor program is deployed.
Coordinator — SolanaListener polls RPC for HTLC program logs and forwards OrderCreated, OrderClaimed, OrderRefunded events into OrderService.
DB — Chain type includes "solana", Direction includes "eth_to_sol" and "sol_to_eth". Migration 002_solana_support.sql upgrades existing databases.
Frontend — useSolanaWallet() handles Phantom connection. Route selector in BridgeForm exposes all four routes. Solana swaps are announced to the coordinator immediately; full settlement goes live once the Anchor program is deployed on devnet.
Asset mappings — resolveSolanaAsset() and resolveEthereumTokenFromSolana() in packages/sdk/src/assets/ cover testnet (devnet USDC) and mainnet (native SOL).

To activate full Solana settlement, deploy the Anchor HTLC program to devnet and set:

SOLANA_RPC_URL=https://api.devnet.solana.com
SOLANA_HTLC_PROGRAM=<your_program_id>

Running a resolver

Anyone who stakes into ResolverRegistry can run a resolver.

docker run ghcr.io/wafflefinance/resolver:latest register
docker run ghcr.io/wafflefinance/resolver:latest run

See resolver/ for environment variable reference.

Deploying contracts

cp env.example .env

# Sepolia testnet
pnpm --filter @wafflefinance/contracts exec hardhat run scripts/deploy.ts --network sepolia

# Mainnet (after audit)
pnpm --filter @wafflefinance/contracts exec hardhat run scripts/deploy.ts --network mainnet

Deployment addresses are written to deployments.<network>.json and picked up automatically by the coordinator and frontend.

Test coverage

Layer	Tests	Framework
Soroban HTLC	10	Rust `#[contracttest]`
Soroban ResolverRegistry	6	Rust `#[contracttest]`
EVM HTLCEscrow	15	Hardhat + Chai
EVM ResolverRegistry	6	Hardhat + Chai
SDK	8	Vitest
Coordinator	4	Vitest

All suites gate every pull request via GitHub Actions.

Key environment variables

All environment variables across the monorepo packages are consolidated and validated using the shared @wafflefinance/config package (under packages/config). Invalid or missing values fail fast with clear, actionable validation messages at startup.

Variable	Used by	Description
`ETHEREUM_RPC_URL`	relayer, coordinator	Sepolia or mainnet RPC
`RELAYER_PRIVATE_KEY`	relayer	ETH signing key
`RELAYER_STELLAR_SECRET`	relayer	Stellar signing key
`SOLANA_RPC_URL`	coordinator	Solana RPC endpoint
`SOLANA_HTLC_PROGRAM`	coordinator	Anchor program ID (leave blank for simulation mode)
`NETWORK_MODE`	relayer, frontend	`testnet` or `mainnet`
`VITE_MAINNET_ENABLED`	frontend	Set `true` post-audit to unlock mainnet UI

Full reference in env.example.

License

MIT. See LICENSE.

Name		Name	Last commit message	Last commit date
Latest commit History 257 Commits
.devcontainer		.devcontainer
.github		.github
.kilo		.kilo
contracts		contracts
coordinator		coordinator
docs		docs
e2e		e2e
frontend		frontend
packages		packages
relayer		relayer
resolver		resolver
scripts		scripts
soroban		soroban
.editorconfig		.editorconfig
.eslintrc.json		.eslintrc.json
.gitignore		.gitignore
.nvmrc		.nvmrc
.prettierrc		.prettierrc
CHANGES.md		CHANGES.md
GAS_REGRESSION_GUIDE.md		GAS_REGRESSION_GUIDE.md
README.md		README.md
RELEASE_IMPROVEMENTS_SUMMARY.md		RELEASE_IMPROVEMENTS_SUMMARY.md
RELEASE_POLICY.md		RELEASE_POLICY.md
deployments.testnet.json		deployments.testnet.json
env.example		env.example
package.json		package.json
pnpm-lock.yaml		pnpm-lock.yaml
pnpm-workspace.yaml		pnpm-workspace.yaml
renovate.json5		renovate.json5
tsconfig.base.json		tsconfig.base.json
vercel.json		vercel.json

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WaffleFinance

What it is

Supported chains

How it works

Trust model

Deployed contracts (testnet)

Refund layers

Repository layout

Quick start

Wallet support

Solana integration

Running a resolver

Deploying contracts

Test coverage

Key environment variables

License

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WaffleFinance

What it is

Supported chains

How it works

Trust model

Deployed contracts (testnet)

Refund layers

Repository layout

Quick start

Wallet support

Solana integration

Running a resolver

Deploying contracts

Test coverage

Key environment variables

License

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