# SwisstronikJS SDK

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**SwisstronikJS SDK is required for** **any smart contract interaction** (e.g. calling a function within a smart contract)
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To make sure your interactions with the Swisstronik blockchain go smoothly, it's essential to use SwisstronikJS. This guarantees the security of your data by encrypting it before sending transactions and decrypting responses from the nodes. 

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No encryption is needed for smart contract **deployment**.
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### What is SwisstronikJS SDK?

Swisstronik JS SDK is a JavaScript library designed to enhance the privacy of interactions within the Swisstronik blockchain by encrypting the data of the transactions & decrypting the queries from the nodes. It offers a suite of encryption and decryption functionalities, enabling developers to safeguard sensitive data within Swisstronik decentralized applications (dApps).

### How to Install SwisstronikJS SDK?

Open your terminal and navigate to the main root of your Hardhat project. From there, you can run the command `npm i @swisstronik/utils`

### Blockchain interaction

There are 2 types of functions you can invoke within a blockchain:

1. **Writing functions** [**(Transactions)**](/swisstronik-docs/development/swisstronikjs-sdk/swisstronik-and-ethereum-transactions.md)**:** Functions that write, change, or delete any value in a smart contract.
2. **Reading functions** [**(Calls or Queries)**](/swisstronik-docs/development/swisstronikjs-sdk/swisstronik-and-ethereum-calls.md)**:** View functions in the blockchain, where you don't change any state of a smart contract, instead, you retrieve the value of a variable within a smart contract.


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