Blockchain indexer & api service

A proof of concept (POC) implementation of multichain indexer for ethereum based chains and layer 2 solutions.

Description

• Scans multiple ethereum based chains and layer 2 blockchain nodes
• Provides api's to fetch tx history of address across multiple chains
• Exposes adapter to publish transaction details

System Requirements

• Built on node version: v20.9.0
• NodeJS LTS version
• MySql

SDK's Used in this project

• Sequelize

How to setup

clone the repo and cd blockchain-indexer

npm install

Enviroment setup

See enviroment variables in src/config.ts

DB_URL=mysql://john:doe@localhost:3306/indexer
DB_HOST=127.0.0.1
DB_NAME=indexer
DB_PORT=3306
DB_USER=john
DB_PASS=doe

Running the project

npm run start 

Run with docker

docker compose up

Chain config

• See src/config.ts for chain config
• Feel free to add more EVM compatible chains
• Currently src/config.ts includes ETH and GNOSIS chains

Running on local

To start the server, run the following

npm start

API Documentation

Get txs for an address:

URL Format

http://localhost:3000/api/<chainName>/<testnet|mainnet>/address/<address>/txs

Example

http://localhost:3000/api/ETH/testnet/address/0xb733B99F0f9b690C47004A835CA25e32992194DF/txs

Example get sync status

http://localhost:3000

Example get block

http://localhost:3000/api/GNOSIS/mainnet/block/1000

Example get tokens information of an address

http://localhost:3000/api/ETH/testnet/address/0xb733B99F0f9b690C47004A835CA25e32992194DF/coins

Adapter for transaction analyzers

Adapter implementation is not concerete ... just sharing ideas

• It could be exposed via websockets interface
• External analyzer could register a callback to receive the tx or blocks
• OR it could be a json rpc interface served over http

Architecture Diagram

Database Design

Design should be included but see src/models folder for now

Directory structure

src 
|____types
| |____Class.ts
| |____Config.ts
| |____ChainNetwork.ts
| |____Worker.ts
|____utils
| |____wait.ts
|____models
| |____State.ts
| |____Block.ts
| |____Transaction.ts
|____logger.ts
|____config.ts
|____modules
| |____eth
| | |____p2p
| | | |____p2p.ts
| | | |____sync_worker
| | | | |____syncWorker.ts
| | | | |____sync.ts
| | |____index.ts
| |____index.ts
|____server.ts  <--- Entry point
|____routes
| |____adapter
| | |____index.ts
| |____api
| | |____block.ts
| | |____transaction.ts
| | |____address.ts
| |____index.ts
|____services
| |____storage.ts
| |____api.ts
| |____p2p.ts
| |____config.ts
| |____worker.ts

See NOTES.md

• See NOTES.md file for more information
• See comments in code for more understanding

Contributions

Contribute to blockchain indexer by opening a pull request. See contributions.md for more details.

Last updated: 25 December, 2024