A Scala framework for the development of general-purpose analytics on blockchains, created by Livio Pompianu, Stefano Lande.

Our framework allows to combine data within the blockchain with data from the outside (e.g. exchange rates and tags). The workflow consists in two steps:

1. construct a view of the blockchain and save it in a database;
2. analyse the view by using the query language of the database.

The blockchains currently supported are Bitcoin and Ethereum. The DBMS currently supported are MongoDB and MySQL.

The library is dicussed in A general framework for blockchain analytics, in proceeding of the SERIAL workshop 2017.

More material is available in the project page.

The Scaladoc is uploaded on this repository in the doc folder.

Prerequisites depends on the target analyses. Generally speaking the framework needs at least one blockchain client and one DBMS.

1. Blockchain clients:
   • Bitcoin Core (extracts data from Bitcoin)
   • Parity (extracts data from Ethereum)
2. DBMS:
   • MongoDB (constructs a NoSQL view of the data)
   • MySQL (constructs a SQL view of the data)
   • PostgreSQL (constructs a SQL view of the data)
3. Either
   • use an IDE for executing a Scala SBT project (we used IntelliJ IDEA) or
   • use the command line in place of an IDE (Install SBT)

Before building the project, execute the following commands:

git clone https://github.com/bitbart/bitcoinj.git
cd bitcoinj
git checkout segwit
mvn install -DskipTests
cd core
mvn install -DskipTests

In order to use the ICO class (created to retrieve ICOs data) you must require the respective API keys:

1. EtherScan
   • It is sufficient to sign up and then go here
2. ICOBench
   • Sign Up, then require an API key here
3. Ethplorer
   • There is a default, free key: freekey. If you need more data or highload of service, you can to get personal API key.

After doing these steps, do the following:

1. Copy EtherScan key into EtherScanAPI.apiKey attribute
2. Copy ICOBench private key and public key into ICOBenchAPI.privateKey and ICOBenchAPI.publicKey attributes respectively
3. Copy Ethplorer key into EthplorerAPI.apiKey attribute

1. Execute the blockchain client in order to obtain a local copy of the target blockchain (this process may take several hours)
2. Enable the client RPC calls.
   • In the Bitcoin Core case

     bitcoind -datadir=path/to/blockchain -server -rpcuser=user -rpcpassword=password -rpcserialversion=0

3. Run a localhost instance of the DBMS on the default port.
4. Clone this repository.
5. From your IntelliJ welcome screen: select "Import Project" and open the build.sbt file from your repository directory.

1. Execute of one of the available examples. Either
   • open the file from your IDE and select run or
   • use the command line: from the root directory of the project, execute

     sbt "runMain tcs.examples.ClassName"

Our framework will build the selected database. Then you can query it for performing your analysis. For each available Scala script, we provide some default queries along with the resulting csv files.

The authors thank the following students of the Department of Mathematics and Computer Science of the University of Cagliari for their valuable contributions:

• Daniele Stefano Ferru - First extension to support the Ethereum blockchain, analysis of ICOs
• Nicola Atzei - Improvements on Ethereum
• Andrea Corriga, Omar Desogus, Enrico Podda - Empty blocks on Ethereum
• Giacomo Corrias, Francesco Pisu - Empty blocks on Bitcoin
• Giancarlo Lelli - Bitcoin pools
• Fabrizio Chelo, Hicham Lafhouli, Antonello Meloni - Signature hash types
• Giovanni Laerte Frongia, Luca Pitzalis - Verified contracts from Etherscan.io
• Filippo Andrea Fanni, Martina Senis, Alessandro Tola - Ethereum pools
• Riccardo Mulas - Non-standard transactions