How AlignBTC works
An AI-native credit-risk underwriter for Bitcoin DeFi. It scores a borrower's on-chain Stacks history to unlock capital-efficient, under-collateralised lending — built for the Stacks Endowment grant.
Overview
Stacks-based lending protocols today require heavy over-collateralisation because no on-chain credit profiling exists. AlignBTC closes that gap: a machine-learning model parses a wallet's historical behaviour — transaction frequency, Stacking participation, and stablecoin usage — to generate an autonomous trust score (0–100).
That score is surfaced here and connected to a Clarity escrow contract on testnet, demonstrating a credible path to under-collateralised micro-lending on Bitcoin and increasing capital efficiency across sBTC markets.
The Problem
Bitcoin DeFi on Stacks is structurally constrained by the absence of native credit infrastructure. Current protocols operate fully collateralised — borrowers must lock sBTC or STX worth more than the loan. This:
- Excludes users with strong repayment histories but little collateral
- Locks capital inefficiently, reducing the velocity of sBTC
- Makes micro-lending economically unviable at current ratios
The data exists — every Stacks address has a public, auditable history — but no tooling aggregates and scores it in a lending-relevant format.
How It Works
Three independently testable layers turn wallet history into a loan offer:
1 · Data pipeline (Python)
Aggregates on-chain wallet metrics from the Stacks Extended API — full transaction history, Stacking participation, and USDCx stablecoin transfers — into a feature vector per address.
2 · ML scoring engine (scikit-learn)
A Random Forest classifier (max_depth 6, 100 estimators, 5-fold CV) trained on labelled wallet profiles outputs a probability normalised to a 0–100 trust score. Target AUC-ROC ≥ 0.72.
3 · Presentation (Next.js + Clarity)
A FastAPI service serves the score as JSON. This frontend renders the score, feature breakdown, and a simulated loan offer — priced by a Clarity escrow stub deployed on Stacks testnet.
Trust Score
The model encodes each wallet as a feature vector across seven dimensions. Each contributes a weighted share of the final score:
Wallet Age · 15%
Days since first on-chain activity
Activity (90d) · 20%
Transactions in the last 90 days
Avg Tx Value · 10%
Mean STX moved per transaction
Stacking Cycles · 20%
Completed Stacking cycles
Stacking Streak · 15%
Consecutive cycles without interruption
Stablecoin Usage · 10%
USDCx send/receive events
DeFi Footprint · 10%
Distinct DeFi contracts used
Collateral Tiers
The trust score maps to a required collateral ratio. A higher score unlocks a lower requirement — the core of the capital-efficiency thesis. These tiers are enforced on-chain.
| Trust score | Collateral | Tier |
|---|---|---|
| Below 40 | 150% | Subprime |
| 40 – 70 | 120% | Standard |
| Above 70 | 100% | Prime |
Smart Contract
A Clarity escrow stub is deployed on Stacks testnet. Its initiate-loan function accepts a trust score and enforces the tiered collateral above; quote-collateral prices a loan without writing state. No funds move — this is a read-only/parameter-reading MVP; full escrow logic is post-grant.
Tech Stack
| Data pipeline | Python 3.11 · pandas · requests · scikit-learn |
| Model serving | FastAPI — REST endpoint returning the trust score as JSON |
| Smart contract | Clarity · Clarinet CLI · Stacks testnet |
| Frontend | Next.js · TypeScript · Tailwind CSS · Stacks.js |
| Deployment | Vercel (web) · Railway/Render (API) · GitHub (MIT) |
Roadmap
Weeks 1–4
Data pipeline & dataset
Parsing scripts aggregating wallet metrics; an exported labelled dataset of ≥ 500 records.
Weeks 5–8
Trained model & serving
Random Forest producing a 0–100 score with AUC-ROC ≥ 0.72; FastAPI scoring service. (50% tranche.)
Weeks 9–12
Frontend, contract & demo
Leather wallet integration showing score + simulated loan offer; Clarity escrow stub on testnet; demo video. (Final tranche.)
FAQ
Is this live on mainnet with real funds?
No. This is a testnet proof-of-concept. No mainnet loan origination or capital deployment happens in the grant period — and no funds move in the contract stub.
Does AlignBTC use KYC or off-chain identity?
No. Scoring uses purely public, on-chain Stacks signals — there is no identity or KYC integration.
Which chains are supported?
Stacks only. Non-Stacks chains and sBTC bridge interactions are out of scope for this grant.
Is this a lending protocol?
No — it is a scoring primitive. The goal is infrastructure any Stacks lending protocol (e.g. Zest, Granite) could integrate to offer differentiated collateral requirements.