Turn wallet history into a clean CSV with cost basis
Intermediate14h1–2
ViemPythonNext.js
17/20Mini Contract Event Indexer
Index a contract's events into SQL in minutes.
Intermediate16h1–2 people16/20 fit
Build Mini Contract Event Indexer for web3 developers in ~16h with 1–2 people. Stack: Viem + DuckDB + Node.js.
Why it wins: Useful developer tooling.
Build flow
01 · Problem
Building dashboards on chain data needs heavy infrastructure.
02 · Solution
Point at a contract ABI, backfill and stream events into DuckDB or Postgres and expose a query page.
03 · Build
- 1Read ABI
- 2Fetch logs
- 3Write to DuckDB
- 4Add query UI
04 · Demo
Index a token's transfers and query top holders.
MVP checklist
- ABI import
- Backfill
- Live stream
- SQL page
Tech stack
| Tech | Role | |
|---|---|---|
| Viem | Ethereum client | Chain |
| DuckDB | In-process analytics SQL | Data |
| Node.js | Backend runtime | Backend |
Reference repos
Open-source projects you can build on. Links checked 2026-10-31.
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