Mini blockchain explorer

Block explorer and the most powerful API for the most popular blockchains that allows you to find, sort, and filter blockchain blocks, transactions, … In this blueprint we try to demonstrate the some basic functionality of blockexplorer.


  • Golang > 1.18
  • Two microservices
  • Using docker-swarm as orchestrator
  • gRPC internal connection



The two microservices should be:

  1. Indexer (blockchain scanner)
  2. Public facing REST API

A) Indexer

This backend service should scan for transactions and capture block information:

  • number of transactions
  • transaction details (hash, from, to, amount) Captured data can be inserted into the database.

The indexer can be able to scan the range if given from-to parameters, or simply subscribe to the latest blocks.


  • Indexer 100 200 should scan all blocks from 100 to 200 (inclusive)
  • Indexer 100 should scan all blocks starting from 100 to the latest, once reached the top it should subscribe to new incoming blocks
  • Indexer should scan for all blocks if they don’t already exist in the database

B) Restful api delivery


docker-compose -p mini-indexer up -d

Public API

REST API with the following endpoints:

  • /block [GET]
  • /stats [GET]
  • /tx [GET]
  • /index [POST]


  • /block – returns the latest block and all associated transactions
  • /block/100 – returns the block number 100 and all associated transactions
  • /stats – returns sum of all amounts and transactions
  • /stats/100:200 – return sum of all amounts and transactions between blocks 100 and 200
  • /tx – return latest transaction
  • /tx/0x... – return the transactions with the specified hash
  • index/?auth_token&scan=100:200 – instructs our service to trigger indexer for a fresh scan of blocks between 100 and 200

To Do

[X] Fix problem in energy_indexing-srv once disconnected from index-engine


View Github