Overview
KeywordChain is a blockchain-based message chain where each new message must start with the last message’s keyword, enforcing continuity and a “story-like” flow. The next keyword is extracted from the last word of the new message. It’s implemented as a Solidity smart contract on Sepolia, paired with a frontend that lets users connect a wallet, browse messages with pagination, and submit new entries with client-side validation.
What it demonstrates
- Constraint-driven onchain data design (prefix rule + last-word keyword derivation)
- Input validation + custom errors for gas efficiency
- Pagination + exact-keyword search patterns for onchain message retrieval
- Full dApp integration: wallet connect → read/write → UI feedback
Design notes (why this matters)
- Custom errors reduce gas and make failures explicit at the ABI level
- The 256/32 character caps keep storage predictable and UI consistent
- Pagination avoids heavy reads and keeps UX responsive onchain
- Future anti-spam controls fit the public nature of the chain
Contract details
- Contract:
MessageChain - Network: Sepolia (Chain ID: 11155111)
- Address:
0xAD17ee34a3A2b59727C08E992a84a1F160BF21C0 - Rule: message must start with last message’s keyword
- Keyword derivation: last word of message
- Limits:
- Message length max: 256 chars
- Keyword length max: 32 chars
- Keyword charset: alphanumeric
This deployment is on Sepolia (testnet). Data and ETH there are for testing only.
Live demo
Quickstart (repo)
Bash
git clone https://github.com/casaisdev/KeywordChain.gitFor install/run/env vars, see the repo README.
Next steps
If I were to evolve KeywordChain further:
- Add an indexer-backed search layer (fast global keyword search + better UX)
- Add anti-spam controls for public deployments (rate limits / allowlists / fees)
- Add clearer UI “next keyword” guidance (show the required keyword prominently)
- Improve pagination UX (infinite scroll + cached pages)
- Add richer analytics (messages per keyword, user activity, trend keywords)