Transaction Indexer

Simple transaction indexing service for Ethereum blockchains. This service will index transactions, provide a REST API to query all transactions related to a given address and a Socket.IO subscription mechanism to be notified when new transactions are indexed.

REST API

GET /addresses/:address/transactions[?from=<number>&to=<number>]

Will return a JSON array having all Ethereum transaction IDs related to the given address. Optionally specify from and to to limit the query to only that block range.

[
  "0xed3a75ab0677e1a4b24874c5f9ac1a6c38a1b419ff7616fb3ed764713095bf10",
  "0xbfbff2e8bbddbb0575120366be9d2b7dd7f231f8375c43cbb5629ae01ed0003f",
  "0x735df07d3d73a3f95355e0d6bd6c0a8ce1b5922834b7db372b18888ff2660b55",
  "0xc54fb504aa7cfedadd0a25623dc568a7ed8bdf92920520639df785729f580868"
]

Transactions are returned in reverse-chronological order.

GET /blocks/best

Will return an object containing information on the best indexed block.

{
  "number": 1828,
  "hash": "0xe04c1cded9a4724d8b22a8f7d6558f778392253ae61a2672a2242c60fe8992df",
  "totalDifficulty": "342830896"
}

Events interface

The Socket.IO events interface is available at the following route: /v1.

subscribe

Will allow the subscriber to start receiving notifications of new transactions indexed related to the given addresses.

Subscription message:

{
  "event": "subscribe",
  "data": {
    "type": "txs",
    "addresses": ["0xb1d4c88a30a392aee6859e6f62738230db0c2d93"]
  }
}

Subscription responses:

{
  "event": "tx",
  "data": {
    "txid": "0x64473dec378049472234c854d53f2ce92cd7a94468b62f785b683a9cacdb7f86",
    "status": "confirmed"
  }
}

The data object has the following properties:

• txid is the indexed transaction id.
• status can be confirmed or, in the case of a blockchain reorg, it could be removed.

Requirements

• Ethereum node (i.e. Geth or Parity)
• MongoDB v4 or Redis v4
• Node.JS

Configuration

Default configuration can be customized by setting environment variables or createing an <environment>.json or <hostname>.json file in the config folder following the config module guidelines.

Start

Install dependencies with npm install and then start the indexer or the API with npm run indexer or npm run api.

Optionally, for test and development purposes, start both components with npm start.

The indexer API will listen on the port 3005 by default.

Convenience all-in-one install & run script

To easily install and execute the indexer in a single AWS EC2 Ubuntu VM, clone the repository, set the following environment variables and execute the script setup.sh:

• COIN: eth or etc
• CHAIN: mainnet or the name of the chain param required by Parity.
• ENV: prod or test
• PAPERTRAIL_HOST: logs.papertrailapp.com or the proper logging URL
• PAPERTRAIL_PORT: to the proper port

The script will:

• Install and start Parity in a tmux session parity.
• Install, configure and start remote-syslog2 to send Parity logs to Papertrail.
• Install MongoDB.
• Install Node.js.
• Setup and start the indexer, both the parser and the API in the same process, in a tmux session indexer.

During the synchronization phase, a c5.2xlarge VM type is recommended to provide enough CPU capacity and at least 16 GBytes of RAM. After both Parity and the indexer are up to date, the VM type could be switched back to t3.xlarge or similar.

The storage required is:

Coin	Chain	Storage
ETH	mainnet	128 GBytes (estimated)
ETH	testnet (ropsten)	32 GBytes (estimated)
ETC	mainnet (classic)	32 GBytes (estimated)
ETC	testnet (morden)	24 GBytes

License

MIT