What we built

InkFi turns every article into a financial primitive. Three composable layers, all settled on OPN Chain.

• ArticleNFT — soulbound ERC-721. Every published article is an NFT owned permanently by its writer. Authorship can never be transferred, only versioned.
• ArticleVaultPool — per-article staking. Fans deposit OPN on articles they believe in. When that article is tipped, stakers earn a pro-rata share through a Synthetix-style accumulator (accRewardPerShare). One contract serves N pools, gas-efficient packed storage.
• TippingRouter — single entrypoint splitting every tip 70/25/5 between writer, stakers, and protocol treasury. Tips stop being one-shot — they generate continuous yield for fans who curated early. If a vault has no stakers, the staker share is auto-redirected to the writer so funds are never stuck.
• InkStream — per-second subscription streaming. OPN flows from reader to writer continuously. This is only economically viable because OPN Chain has roughly one second block time. On Ethereum mainnet a per-second stream would be useless.

Why

Web2 publishing pays writers via ads, paywalls, and middlemen taking 30 to 70 percent. Decentralized publishing (Mirror, Paragraph, my own Inkrun on Solana) solved censorship but kept the same broken monetization: one-shot tips and nothing else. InkFi treats each article as a programmable yield-bearing asset and gives readers an economic stake in articles they discover before they go viral. That is the open finance angle: replace platform rent with on-chain primitives.

How it works end to end

1. Writer publishes an article. A soulbound ArticleNFT is minted.
2. A reader stakes OPN into that article's ArticleVaultPool.
3. Other readers tip the article in native OPN through TippingRouter.
4. Router wraps to WOPN, splits 70/25/5, pushes the staker share to the pool, calls notifyReward(articleId, amount).
5. Stakers' pending rewards crystallise. Anyone can claim() independently.
6. Writers can also receive per-second subscriptions through InkStream, withdrawable continuously.

Why this scores against the rubric

• OPN Chain Integration (30) — five contracts deployed, all load-bearing. Per-second streaming and micro-tipping are unaffordable on slower or more expensive chains.
• Technical Quality (25) — Solidity 0.8.30, paris EVM target, viaIR optimizer, packed structs, custom errors. 11/11 Hardhat tests covering soulbound, splits, late-staker accounting, stream caps, access control. Flattened sources committed.
• Product & UX (20) — Next.js 14 dApp with three flows (write, tip+stake on article, open+manage stream). Live deployment at https://inkfi.vercel.app.
• Innovation (15) — "creator DeFi": articles as composable yield-bearing assets, staker discovery rewards, reputation-aware streaming as the path to credit.
• Builder Commitment (10) — continuation of Inkrun (https://inkrun.vercel.app), full multi-component delivery (contracts + web + Node CLI + Python analytics), public roadmap.

Stack

Layer	Tech
Contracts	Solidity 0.8.30 + Hardhat + OZ 5.0.2
Web	Next.js 14 + wagmi v2 + viem + RainbowKit
CLI	Node + viem (11 commands, auto-wrap and approve)
Analytics	Python + web3.py + rich (live TVL leaderboard)

Roadmap, short version

Q3 2026: IPFS for content URIs, Writer Credit (borrow against future stream income), subgraph and discovery feed. Q4 2026: reputation NFT tiers feeding credit scoring, multi-asset streams, mobile PWA, external audit. 2027+: DAO governance, cross-chain settlement, public SDK.