Indexer for Ethereum to get transaction list by ETH address

Known Ethereum nodes lack functionality to get transaction list for ETH address (account). This Indexer allows to explore ETH and ERC20 transactions by Ethereum address and obtain a history of any user|wallet in just a move, like Etherscan does.

Indexer is written in Python. It works as a service in background:

Connects to Ethereum node (works well with Geth, Nethermind or other node, which provides http/ws/ipc API)
Stores all transactions in Postgres database
Provides data for API to get transactions by address with postgrest

Stored information

All indexed transactions includes (database field names shown):

time is a transaction's timestamp
txfrom sender's Ethereum address
txto recipient's Ethereum address
value stores amount of ETH transferred
gas indicates gasUsed
gasprice indicates gasPrice
block is a transaction's block number
txhash is a transaction's hash
contract_to indicates recipient's Ethereum address in case of contract
contract_value stores amount of ERC20 transaction in its tokens
status tx status

To reduce storage requirements, Indexer stores only token transfer ERC20 transaction, started with 0xa9059cbb in raw tx input.

An example:

{
  "time": 1576008898,
  "txfrom": "0x6B924750e56A674A2Ad01FBF09C7c9012f16f094",
  "txto": "0x1143E097e134F3407eF6B088672CCECE9A4f8CDD",
  "gas": 21000,
  "gasprice": 2500000000,
  "block": 9084957,
  "txhash": "0xcf56a031dfc89f5a3686cd441ea97ae96a66f5809a4c8c1b370485a04fb37e0e",
  "value": 1200000000000000,
  "contract_to": "",
  "contract_value": "",
  "status": true
}

Refers to transaction 0xcf56a031dfc89f5a3686cd441ea97ae96a66f5809a4c8c1b370485a04fb37e0e.

Ethereum Indexer's API

To get Ethereum transactions by address, Postgrest is used. It provides RESTful API to Postgres index database.

After index is created, you can use requests like

curl -k -X GET "http://localhost:3000/?and=(contract_to.eq.,or(txfrom.eq.0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98,txto.eq.0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98))&order=time.desc&limit=25"

The request will show 25 last transactions for Ethereum address 0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98 (Bittrex), ordered by timestamp. For API reference, see Postgrest.

Ethereum Indexer Setup

Prerequisites

Ethereum node with RPC API enabled: Geth, Nethermind, etc.
Python 3
Postgresql
Postgrest for API
nginx or other web server (in case of public API)

Installation

Ethereum Node

Make sure your Ethereum node is installed and is fully synced. You can check its API and best block height with the command:

curl --data '{"method":"eth_blockNumber","params":[],"id":1,"jsonrpc":"2.0"}' -H "Content-Type: application/json" -X POST localhost:8545

Python modules

Install Python 3. Install python modules:

apt install python3-pip
pip3 install web3
pip3 install psycopg2

PostgreSQL

Install Postgres. Create Postgres user:

createuser -s api_user

Where api_user is a user who will run indexer service. (As example we create superuser. You can use your own grants.)

Create database index for Ethereum transaction index:

CREATE DATABASE index;

Add tables into index using SQL script create_table.sql:

psql -f create_table.sql index

Note, for case insensitive comparisons we use citex data type instead of text.

Remember to grant privileges to psql database and tables for users you need. Example:

\c index
GRANT ALL ON ethtxs TO api_user;
GRANT ALL ON aval TO api_user;
GRANT ALL ON max_block TO api_user;
GRANT ALL PRIVILEGES ON DATABASE index TO api_user;
GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA public TO api_user;

Ethereum transaction Indexer

ethsync.py is a script which makes Ethereum transaction index. It accepts the following env variables:

DB_NAME: Postgres database name. Example: index.
ETH_URL: Ethereum node url to reach the node. Supports websocket, http and ipc. See examples in ethsync.py.
START_BLOCK: the first block to synchronize from. Default is 1.
CONFIRMATIONS_BLOCK: the number of blocks to leave out of the synch from the end. I.e., last block is current blockNumber - CONFIRMATIONS_BLOCK. Default is 0.
PERIOD: Number of seconds between to synchronization. Default is 20 sec.
LOG_FILE: optional file path and name where s=to save logs. If not provided, use StreamHandler.

Indexer can fetch transactions not from the beginning, but from special block number START_BLOCK. It will speed up indexing process and reduce database size. For a reference:

index size starting from 5,555,555 block to 9,000,000 is about 190 GB
index size starting from 11,000,000 block to 12,230,000 is about 83 GB
index size starting from 14,600,000 block to 15,100,000 is about 27 GB

At first start, Indexer will store transactions starting from the block you set. It will take a time. After that, it will check for new blocks every PERIOD seconds and update the index.

Sample run string:

DB_NAME=index ETH_URL=http://127.0.0.1:8545 START_BLOCK=14600000 LOG_FILE=/home/api_user/ETH-transactions-storage/ethsync.log python3 /home/api_user/ETH-transactions-storage/ethsync.py

We recommend to run Indexer script ethsync.py as a background service to make sure it will be restarted in case of failure. See ethsync.service as an example. Copy it to /lib/systemd/system/ethsync.service, update according to your settings, then register a service:

systemctl start ethsync.service
systemctl enable ethsync.service

Note, indexing takes time. To check indexing process, get the last indexed block:

psql -d index -c 'SELECT MAX(block) FROM ethtxs;'

And compare to Ethereum node's best block.

Troubleshooting

To test connection from script, set a connection line in ethtest.py, and run it. In case of success, it will print current Ethereum's last block.

To test a connection to a Postgres database index, run pgtest.py.

Transaction API with Postgrest

Install and configure Postgrest. Here is an example to run API for user api_user connected to index database on 3000 port:

db-uri = "postgres://api_user@/index"
db-schema = "public"
db-anon-role = "api_user"
db-pool = 10
server-host = "127.0.0.1"
server-port = 3000

Make sure you add Postgrest in crontab for autostart on reboot:

@reboot cd /usr/share && /usr/bin/postgrest ./postgrest.conf

Make Indexer's API public

If you need to provide public API, use any web server like nginx and setup proxy to Postgrest port in config:

location /ethtxs {
    proxy_pass http://127.0.0.1:3000;
}
location /aval {
    proxy_pass http://127.0.0.1:3000;
}
location /max_block {
    proxy_pass http://127.0.0.1:3000;
}

This way endpoints will be available:

/ethtxs used to fetch Ethereum transactions by address
/aval returns status of service. Endpoint aval is a table with status field just to check API availability.
/max_block returns max Ethereum indexed block

Example:

https://yourdomain.com/max_block

Dockerized and docker compose

by Guénolé de Cadoudal ([email protected])

In the docker-compose.yml you find a configuration that show how this tool can be embedded in a docker configuration with the following processes:

postgres db: to store the indexed data
postgREST tool to expose the data as a REST api (see above comments)
GETH node in POA mode. Can be Openethereum, or another node, but not tested
EthSync tool (this tool)

Set env variables.

API request examples

Get last 25 Ethereum transactions without ERC-20 transactions for address 0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98:

curl -k -X GET "http://localhost:3000/ethtxs?and=(contract_to.eq.,or(txfrom.eq.0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98,txto.eq.0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98))&order=time.desc&limit=25"

Get last 25 ERC-20 transactions without Ethereum transactions for address 0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98:

curl -k -X GET "http://localhost:3000/ethtxs?and=(contract_to.neq.,or(txfrom.eq.0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98,txto.eq.0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98))&order=time.desc&limit=25"

Get last 25 transactions for both ERC-20 and Ethereum for address 0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98:

curl -k -X GET "http://localhost:3000/ethtxs?and=(or(txfrom.eq.0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98,txto.eq.0xFBb1b73C4f0BDa4f67dcA266ce6Ef42f520fBB98))&order=time.desc&limit=25"

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Adamant-im/ETH-transactions-storage

Adamant-im

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