CompraBTC

Non-custodial Bitcoin DCA agent on Celo. Define your plan once — $X every hour/day in BTC — and an on-chain agent buys Bitcoin for you, straight into your own wallet. Funds never leave your wallet between purchases.

• Live app: https://comprabtc.vercel.app (works in MiniPay and any injected wallet)
• Agent API: https://comprabtc-production.up.railway.app (GET / service descriptor · GET /api/stats public metrics)
• Built for the Celo Agentic Payments & DeFAI Hackathon — leaderboard

Deployed contracts (Celo mainnet, chain 42220)

Contract	Address
DCAExecutor (verified)	0xd03ffeBBCaaA8aA21053eEB0EeAde39EFC504189
USDT (token in)	0x48065fbBE25f71C9282ddf5e1cD6D6A887483D5e
WBTC — native bridge (token out)	0x8aC2901Dd8A1F17a1A4768A6bA4C3751e3995B2D
Uniswap V3 SwapRouter02	0x5615CDAb10dc425a742d643d949a7F474C01abc4

Swaps route through the USDT/WBTC 0.3% Uniswap V3 pool. Protocol fee: 1% + $0.005 flat per execution, with on-chain hard caps (≤1%, ≤$0.05 flat) and a revert if the fee would ever eat the installment.

Agent identity: ERC-8004 #9665 on Celo mainnet (8004scan). Every transaction carries ERC-8021 attribution tags.

How it works

flowchart TB
    USER["👤 User wallet<br/>(MiniPay / MetaMask / Valora)"]
    FE["Frontend — Next.js PWA<br/>(Vercel)"]

    subgraph onchain["⛓️ Celo mainnet"]
        USDT["USDT (ERC-20)"]
        EXEC["DCAExecutor<br/>0xd03f…4189<br/>non-custodial, on-chain limits"]
        ROUTER["Uniswap V3 SwapRouter02<br/>USDT/WBTC 0.3% pool"]
        TREASURY["Treasury"]
    end

    subgraph backend["🤖 Agent backend — Railway"]
        KEEPER["Keeper (cron 60s)<br/>scans PlanCreated events,<br/>checks due plans"]
        API["Express API<br/>POST /api/execute<br/>(x402-gated, permissionless)"]
        DB[("Supabase<br/>plans · executions")]
        TG["Telegram bot<br/>purchase alerts + ops"]
    end

    FACIL["x402 facilitator<br/>api.x402.celo.org"]

    USER -- "① approve(budget) — once" --> USDT
    USER -- "② createPlan(amount, interval) — once" --> EXEC
    FE -.-> USER
    KEEPER -- "discovers plans<br/>(PlanCreated events)" --> EXEC
    KEEPER -- "③ pays 0.02 USDT via x402<br/>(EIP-3009 signature)" --> API
    API -- "verify + settle" --> FACIL
    API -- "④ execute(user, minOut)<br/>+ ERC-8021 attribution tags" --> EXEC
    EXEC -- "⑤ transferFrom<br/>(one installment)" --> USDT
    EXEC -- "fee 1% + $0.005" --> TREASURY
    EXEC -- "⑥ swap USDT→WBTC" --> ROUTER
    ROUTER -- "⑦ WBTC straight<br/>to the user's wallet" --> USER
    API -- "records execution" --> DB
    API -- "🔔 purchase alert" --> TG

Loading

1. The user approves USDT to DCAExecutor (cap = total plan budget) and creates a plan with on-chain limits (amount per run, minimum interval). Cancelling = one click (cancelPlan or approve(0)).
2. The keeper discovers plans from PlanCreated events, and each cycle pays the execution API with an x402 micropayment before calling execute() — so every purchase is also an agent-to-agent payment.
3. On-chain limits mean even a compromised keeper can't overcharge: it can never pull more than amountPerRun or execute before minInterval elapses.
4. Users get Telegram alerts on every purchase (link from Settings in the app).

Repository layout

Directory	What it is
contracts/	DCAExecutor.sol (Foundry) — 21 tests incl. mainnet fork tests, deploy script
backend/	Express API + keeper loop (viem) + x402 middleware + Supabase + Telegram bot
frontend/	Next.js PWA (wagmi/viem) — MiniPay auto-connect, plan creation, BTC portfolio
docs/	Unit economics, copy review
PLAN.md	Full architecture plan and piece-by-piece feasibility verification

Running locally

Frontend (needs NEXT_PUBLIC_EXECUTOR_ADDRESS, NEXT_PUBLIC_API_URL, NEXT_PUBLIC_ATTRIBUTION_CODE, NEXT_PUBLIC_TELEGRAM_BOT in frontend/.env.local):

cd frontend && pnpm install && pnpm dev   # http://localhost:3000

Backend + keeper (Node 22; see backend/src/config.ts for required env vars — executor address, keeper key, Supabase credentials, x402 API key; DB schema in backend/supabase/schema.sql):

cd backend && pnpm install && pnpm dev    # API on :8080, keeper ticks every 60s

Contracts:

cd contracts && forge test                # unit + Celo mainnet fork tests
forge script script/Deploy.s.sol --rpc-url celo --broadcast --verify --interactives 1

For AI agents

An agent with its own funded wallet can set up a Bitcoin savings plan in two transactions — and so can an agent assisting a human (the web app handles the signing):

• MCP server (treasury DCA): claude mcp add comprabtc -- npx -y comprabtc-mcp — tools to check status, create/renew/cancel the plan and track the portfolio, signing with the treasury's own wallet. See mcp/README.md.
• Agent skill: npx skills add csacanam/comprabtc — covers plan creation (viem), monitoring, budget math, cancelling, and the permissionless x402 execution trigger.
• Service descriptor (machine-readable how-to): GET https://comprabtc-production.up.railway.app/ · LLM index: comprabtc.vercel.app/llms.txt
• Agent identity: ERC-8004 #9665 on Celo — metadata · 8004scan

Hackathon tracks

• Track 1 — on-chain revenue: protocol fee charged inside execute(), every tx tagged with ERC-8021 attribution.
• Track 2 — x402 payments: the keeper pays /api/execute per run via the Celo x402 facilitator. The endpoint is permissionless — any agent can pay to trigger an execution.
• Track 4 — Aigora: agent registered on the Aigora marketplace (#395) + feedback PRs at trionlabs/aigora-skills.

License

MIT