Spark

Pay once. Unlock credit.

Verified Sepolia payment history is your credit score — no oracle.

spark.sithunyein.com · Help · GitHub · MIT License

What it is

Spark proves Sepolia payments with Attestcoin (USC / BlockProver), then opens or clears credit on Creditcoin testnet. No bank forms, no centralized price oracle.

Pay deposit on Sepolia → dual Attestcoin proofs (deposit + ETH balance) → open credit on Creditcoin
Credit score from on-chain attested payment history (650–850)
LTV bonus from linked history (+2.5% at ≥1 payment, +5% at ≥3) plus balance-based LTV
Withdraw sCREDIT, redeem against debt, repay on Sepolia to close

Live app: https://spark.sithunyein.com · Deck: deck.pdf

Demo flow (testnet)

Pay deposit → Verify (Attestcoin ~8–20 min) → Withdraw → Redeem → Repay → Closed

Optional first: link past Sepolia payments on Credit score to raise score and LTV before opening a new line.

Architecture

flowchart TB
  User[Borrower] --> App[Spark App]
  App --> Pay[SepoliaPayment]
  App --> Prover[Attestcoin Proof API]
  Prover --> Verifier[AttestcoinPaymentVerifier]
  Verifier --> Credit[CreditLine]
  Credit --> Token[SparkCredit sCREDIT]

See docs/architecture.md and docs/attestcoin.md.

Project structure

Full repo layout (excluding node_modules/, .next/, contracts/lib/ vendored deps):

spark/
├── .env.example                      # Root env template (optional)
├── .gitignore
├── .gitmodules                       # forge-std submodule
├── package.json                      # Root scripts: dev, build, test:contracts
├── README.md
├── LICENSE
├── SECURITY.md
├── CONTRIBUTING.md
│
├── brand/                            # Logo source (copied into app/public/brand/)
│   ├── logo.png
│   ├── logo-mark.svg
│   ├── logo-on-orange.png
│   ├── logo-on-orange.svg
│   ├── logo-wordmark-dark.svg
│   └── logo-wordmark-light.svg
│
├── docs/
│   ├── addresses.md                  # Production + legacy contract addresses & Vercel env
│   ├── architecture.md               # System diagram, sequences
│   ├── attestcoin.md                 # USC / BlockProver integration
│   ├── deck.md                       # Pitch deck notes
│   └── deploy-vercel.md              # Vercel deploy (root dir = app)
│
├── app/                              # Next.js 15 — Vercel root directory
│   ├── .env.example                  # Local / production env template
│   ├── .gitignore
│   ├── package.json
│   ├── pnpm-lock.yaml
│   ├── next.config.ts
│   ├── next-env.d.ts
│   ├── tsconfig.json
│   ├── postcss.config.js
│   ├── tailwind.config.js
│   │
│   ├── public/
│   │   ├── favicon.svg
│   │   ├── favicon.png
│   │   ├── deck.pdf
│   │   ├── deck.html
│   │   └── brand/
│   │       ├── logo.png
│   │       ├── logo-mark.svg
│   │       ├── logo-on-orange.png
│   │       ├── logo-on-orange.svg
│   │       ├── logo-wordmark-dark.svg
│   │       ├── logo-wordmark-light.svg
│   │       └── metamask.png
│   │
│   └── src/
│       ├── styles/
│       │   └── globals.css
│       │
│       ├── app/                      # App Router
│       │   ├── layout.tsx            # Root layout, providers
│       │   ├── page.tsx              # / → redirect overview
│       │   ├── overview/page.tsx     # Dashboard, score, position, checklist
│       │   ├── pay/page.tsx          # Sepolia deposit + Attestcoin verify + openCredit
│       │   ├── score/page.tsx        # Link history → creditScore + LTV bonus
│       │   ├── withdraw/page.tsx     # Withdraw + redeem sCREDIT
│       │   ├── transfer/page.tsx     # Send & receive sCREDIT
│       │   ├── repay/page.tsx        # Sepolia repay + verify + close
│       │   ├── activity/page.tsx     # Payment journal (sidebar: Payments)
│       │   ├── help/page.tsx         # User guide
│       │   ├── settings/page.tsx     # Wallet, networks, security
│       │   └── advanced/page.tsx     # Developer / contract links
│       │
│       ├── components/
│       │   ├── AppShell.tsx          # Page shell + sidebar
│       │   ├── Sidebar.tsx           # Nav: overview, pay, score, withdraw, …
│       │   ├── Logo.tsx
│       │   ├── ConnectButton.tsx
│       │   ├── ConnectModal.tsx
│       │   ├── AccountMenu.tsx
│       │   ├── MetricCard.tsx
│       │   ├── PositionSnapshot.tsx
│       │   ├── ActivityTable.tsx
│       │   ├── OnboardingChecklist.tsx
│       │   ├── ConfirmingStages.tsx  # Pay/repay stepper
│       │   ├── AttestcoinProofPanel.tsx
│       │   ├── LinkHistoryPanel.tsx  # Credit score linking UI
│       │   ├── SuccessBanner.tsx
│       │   ├── PaymentHistoryStrip.tsx
│       │   └── SimpleChart.tsx
│       │
│       ├── hooks/
│       │   ├── usePaymentActivity.ts # Journal + Sepolia log scan
│       │   └── useChainTxConfirmation.ts
│       │
│       └── lib/
│           ├── config.ts             # NEXT_PUBLIC_* addresses & RPC
│           ├── abi.ts                # Contract ABIs
│           ├── wagmi.tsx             # MetaMask connector, Creditcoin chain
│           ├── sparkInjected.js      # Custom injected connector
│           ├── sparkInjected.d.ts
│           ├── usc.ts                # Attestcoin proof builder (parallel waits)
│           ├── chains.ts             # ensureCreditcoinChain / ensureSepoliaChain
│           ├── errors.ts             # friendlyError messages
│           ├── flowState.ts          # sessionStorage pay/repay resume
│           └── format.ts             # ETH formatting, proof encoding
│
└── contracts/                        # Foundry
    ├── foundry.toml
    ├── foundry.lock
    ├── remappings.txt
    ├── lib/
    │   └── forge-std/                # Git submodule
    │
    ├── src/
    │   ├── SepoliaPayment.sol        # payDeposit, payRepayment, attestBalance
    │   ├── CreditLine.sol            # openCredit, score, history bonus, redeem, repay
    │   ├── AttestcoinPaymentVerifier.sol
    │   ├── SparkCredit.sol           # sCREDIT ERC-20
    │   ├── MockPaymentVerifier.sol   # Unit tests only
    │   └── interfaces/
    │       └── IPaymentVerifier.sol
    │
    ├── test/
    │   └── Spark.t.sol               # Score, history, dual-proof open
    │
    ├── script/
    │   └── Deploy.s.sol
    │
    └── scripts/
        ├── deploy-all.sh
        ├── deploy-attestcoin.ps1
        ├── attestcoin-ctor-args.txt
        └── creditline-ctor-args.txt

Deployed contracts

Production (live site — credit-score stack)

Contract	Network	Address	Verified
SepoliaPayment	Ethereum Sepolia	`0x63F0c69cf9F8b53E8eDD141d07fF2eEd2237ccc4`	Yes (Blockscout)
AttestcoinPaymentVerifier	Creditcoin testnet	`0xF13205Bdf48A3159d4A46309C639930aE8faC130`	Yes
CreditLine (history + score + LTV bonus)	Creditcoin testnet	`0x2C3585019B957b16459C409f34973b583267C742`	Yes (Blockscout)
SparkCredit (sCREDIT)	Creditcoin testnet	`0x1BaDE07F2F3295528a2F7316119813b6846dFfaD`	Yes
BlockProver (USC precompile)	Creditcoin	`0x0000000000000000000000000000000000000FD2`	n/a

Legacy (Aug 13 dual-proof — finish open repay via Repay page)

Contract	Network	Address
SepoliaPayment	Ethereum Sepolia	`0x4B137F56A0b5A8633D079d2d6b34d6aC5CdD22E9`
AttestcoinPaymentVerifier	Creditcoin testnet	`0x372BF96DFfa019A03E861d57CfC8a129172C8A3C`
CreditLine (dual-proof + interest)	Creditcoin testnet	`0x1Ba750b08dC4C06B993DfDedE45d22cbD540D319`
SparkCredit (sCREDIT)	Creditcoin testnet	`0xFa18A5458a973a4E8a3eF327A88262683B64b02b`

Retired stacks and Vercel env values: docs/addresses.md.

Proof of record

On-chain demo wallet: 0x7A35f63F81357DaDE2cff8f5699b935786Aa9Da2. All txs below are on the production CreditLine (0x2C358501…) with real Attestcoin USC proofs (BlockProver TransactionVerified in each tx).

Aug 14 open — 95% LTV (history bonus at cap)

CreditOpened: deposit 0.01 ETH, attested balance ~0.357 ETH, credit 0.0095 ETH, factorBps = 9500 (95% LTV — base 90% + 500 bps history bonus at ≥3 linked payments).

Creditcoin: 0xbbec27e622b18d21bdedb24fabc072041aa0fe3ad7419b952a1e2b8754bba618

Attested payment history — score exercised

5 AttestedPaymentLinked events on production CreditLine (kinds 1 = deposit, 2 = repayment). On-chain creditScore() = 850 (650 base + 5 × 40).

#	Kind	Creditcoin tx
1	deposit	`0xe5ec5506…da9c1`
2	repayment	`0xe7313fef…9f15`
3	repayment	`0x5092e516…18eb4`
4	deposit	`0xbbec27e6…a618`
5	repayment	`0x5fc0b4fb…e122`

Full log index: CreditLine events.

Two full closed loops (Open → Withdraw → Redeem → Repay → Close)

Both loops use real USC proofs end-to-end. Sepolia repay txs linked at close via CreditClosed.

Loop 1 — Aug 13 (factorBps = 9000, credit 0.009 ETH)

Step	Creditcoin tx
Open	`0xe5ec5506…da9c1`
Withdraw	`0xbf411c5a…1f3d`
Redeem	`0x48980365…cfb01`
Repay + close	`0x5092e516…18eb4`

Loop 2 — Aug 14 (factorBps = 9500, credit 0.0095 ETH)

Step	Creditcoin tx
Open	`0xbbec27e6…a618`
Withdraw	`0x3bc160b1…2789`
Redeem	`0x9177c410…d34d`
Repay + close	`0x5fc0b4fb…e122`

Sepolia repayments (kind-2 USC proofs consumed at close):

Loop 1: 0x5fa5d7a2…9785
Loop 2: 0xf3825f7f…ebe6

Quickstart

# Install (from repo root)
pnpm install --dir app

# Contracts
cd contracts && forge test

# App
cd ../app
cp .env.example .env.local   # fill RPC URLs if needed
pnpm dev

Open http://localhost:3000. User guide: in-app Help or spark.sithunyein.com/help.

Deploy

Target	How
App	Vercel, root directory `app` — docs/deploy-vercel.md
Contracts	Foundry `contracts/script/Deploy.s.sol` → update docs/addresses.md + Vercel env

Credit score (on-chain)

Metric	Rule
Score	650 base + 40 × attested payments (cap 850)
LTV bonus	+250 bps (≥1 payment), +500 bps (≥3 payments)
Balance LTV	≥2× deposit → 90%, ≥1× → 85%, else 80% base
Proof	`submitAttestedPayment` links past Sepolia txs; `openCredit` / `repayCredit` also count

Formula lives in contracts/src/CreditLine.sol — readable via creditScore() and getHistory().

Roadmap

Phase	Focus
Now	Live testnet: dual Attestcoin proofs, score, history LTV, full borrow/repay loop
Next	Faster verify UX, stricter log decoding in verifier
Later	Mainnet, audit, single-network UX

Security

Not audited. Testnet only. See SECURITY.md. No private keys on Vercel.

Verifier note: BlockProver proves inclusion; the adapter checks contract, topic, and payer in tx bytes. Fine for demo; production would strict-decode receipts and bind amounts.

License

MIT — LICENSE.

Navigation Menu

Repository files navigation

Spark

What it is

Demo flow (testnet)

Architecture

Project structure

Deployed contracts

Production (live site — credit-score stack)

Legacy (Aug 13 dual-proof — finish open repay via Repay page)

Proof of record

Aug 14 open — 95% LTV (history bonus at cap)

Attested payment history — score exercised

Two full closed loops (Open → Withdraw → Redeem → Repay → Close)

Quickstart

Deploy

Credit score (on-chain)

Roadmap

Security

License

About

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Name		Name	Last commit message	Last commit date
Latest commit History 37 Commits
app		app
brand		brand
contracts		contracts
docs		docs
.env.example		.env.example
.gitignore		.gitignore
.gitmodules		.gitmodules
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
README.md		README.md
SECURITY.md		SECURITY.md
package.json		package.json

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Spark

What it is

Demo flow (testnet)

Architecture

Project structure

Deployed contracts

Production (live site — credit-score stack)

Legacy (Aug 13 dual-proof — finish open repay via Repay page)

Proof of record

Aug 14 open — 95% LTV (history bonus at cap)

Attested payment history — score exercised

Two full closed loops (Open → Withdraw → Redeem → Repay → Close)

Quickstart

Deploy

Credit score (on-chain)

Roadmap

Security

License

About

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