Shared loyalty points that work across neighbourhood stores
Beginner10h1–2
SolidityOpenZeppelinNext.js
17/20Carbon Credit Retirement Tracker
Prove a carbon credit was retired once and only once.
Intermediate16h2–3 people17/20 fit
Build Carbon Credit Retirement Tracker for companies and climate buyers in ~16h with 2–3 people. Stack: Solidity + OpenZeppelin + Next.js.
Why it wins: Climate and web3 overlap with integrity focus.
Build flow
01 · Problem
Double counting undermines trust in carbon credits.
02 · Solution
Tokenise credits with serials, burn on retirement with a public certificate and flag any serial claimed twice.
03 · Build
- 1Write token contract
- 2Implement retire
- 3Generate certificate
- 4Check duplicates
04 · Demo
Retire a credit and show a duplicate claim rejected.
MVP checklist
- Serial tokens
- Retirement burn
- Certificates
- Duplicate detection
Tech stack
| Tech | Role | |
|---|---|---|
| Solidity | Smart contracts | Chain |
| OpenZeppelin | Audited contract library | Chain |
| Next.js | Frontend + API routes | Web |
Reference repos
Open-source projects you can build on. Links checked 2026-10-31.
Related ideas
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