PingPay — Grant Proposal
1. Project Name & Description
PingPay captured the RIF Economy reward from Rootstock at ETHGlobal Prague hackathon. It is the first end‑to‑end digital product sales platform powered by the x402 payment standard, enabled for USDRIF on Rootstock via LayerZero’s OFT token standard.
Creators sell digital files, tools, token-gated content, or subscriptions using wallet-based checkout. Buyers pay in USDRIF on Rootstock; payments are bridged trustlessly to USDC on Base, unlocking x402’s instant, decentralized payment flow. Sellers receive protected content access, analytics, and do not require traditional providers like Stripe or Lemon Squeezy.
ETHGlobal Credential: https://ethglobal.com/showcase/pingpay-vdknr
2. Team Background
Kadir Metehan Caliskan – Blockchain Developer
Blockchain developer and entrepreneur for over 4 years. Bilkent University Electrical and Electronics Engineering graduate. Prev-Nethermind, ETHGLOBAL finalist and co-founder of the Bilkent Blockchain Community, specializes in tokenomics design, smart contracts development.
Linkedin: https://www.linkedin.com/in/metehancaliskan/
Ekim Cem Ulger – Product Developer
Holds a Master’s degree in Engineering Management from METU. Previously, as software lead at placemaking.ai, E-Pixel, 300,000 interactions in 3 months. With 6+ years of experience in startup ecosystems, he developed and launched 30+ products.
Linkedin: https://www.linkedin.com/in/ekimcem/
Alp Kumbasar – Fullstack Developer
Bilkent University Electrical and Electronics Engineering graduate. For the last 4 years, he’s been developing AI powered mobile app products at Bronix.
Linkedin: https://www.linkedin.com/in/abidin-alp-kumbasar-7b424719a/
Omer Basar Ozguven – Fullstack Developer
Bilkent University Mechanical Engineering graduate. Senior full-stack developer with 4 years of experience in startups. Previously published an award-winning paper on robotics systems.
Linkedin: https://www.linkedin.com/in/omerbasarozguven/
Hazal Oyku Cengiz – Marketing
Marketing manager at Bronix for over 1.5 years. Creates content across TikTok and X, and leads social media strategy and community engagement campaigns.
Linkedin: https://www.linkedin.com/in/hazal-öykü-cengiz-1b9a7a206/
Bertan Kofon – Head of Product
Bilkent University Electrical and Electronics Engineering graduate. 3+ years in blockchain, 1 year as product owner at moonshot, co-founder of the Bilkent Blockchain Community, specializes in DeFi, and smart contracts development.
Linkedin: https://www.linkedin.com/in/bertankofon/
3. Total Grant Amount
$14,830 USD total
Requesting $5,550 for Milestone 1. The utilization of funds explained under each milestones.
4. Milestones & Deliverables
Milestone 1: Bridge USDRIF on Rootstock → USDC on Base via batch tx
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Completing batch transection aggregator on Rootstock mainnet to find best route.
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Implementing LayerZero OFT contracts on Rootstock & Base
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Conversion logic (USDRIF →RBTC → USDC.e → USDC on BASE)
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Bridge monitoring dashboard
KPIs:
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Batch aggregator active
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5+ bridged payments completed on mainnet
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Dashboard operational
Duration: 2 weeks
Milestone 1 Budget Breakdown:
| Workstream | Cost (USD) | Description |
|---|---|---|
| Engineering (2 devs × 60 hrs x $35/h) | $4,200 | Core dev of bridge logic, OFT contracts |
| Infrastructure (RPC, Vercel, domain) | $150 | Hosting, bridge dashboard infra |
| Bridge mainnet test (Gas Fees) | $200 | Testing on Rootstock/Base mainnets |
| Bridge Monitoring Dashboard | $1000 | UI/UX + integration with backend for bridge monitoring |
| Total | $5,550 |
Milestone 2: Core Platform & x402 Checkout
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Launch x402-powered sales platform
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Enable creation of payment links (e.g., pingpay.app/pay/abc123) for digital assets
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Build a public digital asset listing page
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Activate payments using USDRIF via x402 standard
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Trigger a webhook for digital product access upon on-chain confirmation of payment
KPIs:
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20+ x402 purchases
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10+ products created
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Payment links tested and accessible publicly
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Listing page showing all active digital products
Duration: 3 weeks
Request: $4,680
Milestone 2 Budget Breakdown:
| Workstream | Cost (USD) | Description |
|---|---|---|
| Frontend Dev (1 dev x 60 hrs x $35/h) | $2,100 | UI/UX for checkout page and listing portal |
| Backend Logic (x402, 1 dev x 50 hrs x $35/h) | $1,750 | Checkout smart contract interaction, webhook logic, building backend architecture for pingpay |
| QA & Bug Fixing | $800 | Ensure functionality across payment scenarios |
| Hosting/Infra | $300 | Ongoing Vercel, Supabase, RPC usage |
| Total | $4,680 |
Milestone 3: Marketplace, Refunds & Advanced Analytics
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Public marketplace with trending, search and profiles
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Manual on‑chain refund feature (Expiration data: a week after payment)
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Best‑selling leaderboard
KPIs:
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50+ marketplace purchases
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10+ seller profiles
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3 successful refunds
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Leaderboard live & accurate
Duration: 2 weeks
Request: $2,500
Milestone 3 Budget Breakdown:
| Workstream | Cost (USD) | Description |
|---|---|---|
| UI/UX for Marketplace | $1,000 | Product exploration, trending, filters |
| Refund Smart Contract | $500 | Expiry-based manual refund logic |
| Analytics Dashboard | $800 | Backend tracking of seller stats and leaderboards |
| QA & Security | $200 | Refund validation and stress tests |
| Total | $2,500 |
Milestone 4: Marketing Campaign, Demo Video & Community Growth
Deliverables:
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Launch of official demo video explaining how PingPay works
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Run social media marketing campaigns (X, Telegram, Discord) to drive early users
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Engage with at least 1 influencer or creator to list a product
KPIs:
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Demo video published on at least 2 platforms (e.g., X & YouTube)
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20+ onboarding threads/posts shared on social media
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100+ new followers/subscribers across platforms
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10+ new seller signups from marketing efforts
Duration: 2 weeks
Request: $2,100
Milestone 4 Budget Breakdown:
| Workstream | Cost (USD) | Description |
|---|---|---|
| Marketing Kit (product video, contents for social media etc.) | $600 | |
| Social Campaigns (X, TG) | $500 | |
| Influencer Partnership | $1,000 | |
| Total | $2,100 |
5. Overall Timeline
| Phase | Dates | Duration |
|---|---|---|
| Milestone 1 | Aug 25 – Sep 10 | 2 weeks |
| Milestone 2 | Sep 11 – Oct 2 | 3 weeks |
| Milestone 3 | Oct 3 – Oct 18 | 2 weeks |
| Milestone 3 | Oct 19 – Nov 3 | 2 weeks |
6. Technical Specifications
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Frontend: Next.js, Wagmi (wallet auth), TailwindCSS, TypeScript
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Backend: Node.js, Supabase (PostgreSQL), LayerZero SDK, x402 logic
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Smart Contracts: Solidity (OFT contracts) on Rootstock & Base
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Bridge: LayerZero OFT + transaction router
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Hosting: Vercel for frontend; AWS
7. Value Proposition for Rootstock
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First x402 implementation using USDRIF, native to Rootstock
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Increases utility and demand for $USDRIF as a means of payment
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Attracts developers to monetizable tools and assets on Rootstock
8. Demo & GitHub Repo
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Demo: https://ping-pay.vercel.app/ (Router is not yet configured on Rootstock. The demo highlights a Proof of Concept for X-402 with basic payments and listings already live. Please don’t execute any transactions)
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GitHub Repo: GitHub - metehancaliskan/PingPay