Integrating with the Quantum Coin blockchain

The steps in this documentation is for usecases like Exchanges, Block Explorers. For example, Exchanges that want to integrate with the Quantum Coin blockchain would need to post transactions, find account balance, scan for new transactions etc. The typical way to do this is to run the blockchain node and the relay on a machine and then use the SDK to perform operations such as posting a transaction, finding account balance etc. Follow the below steps to do this:

Connecting to mainnet is the first step. This involves running the blockchain node on a server. There are two ways to do this:

Method 1

This method of connecting to mainnet involves downloading all blocks starting from the genesis block till the latest block. Note that this method can take order of weeks to complete.
Follow steps in: Connecting to mainnet.

Method 2

This method of connecting to mainnet involves using a pre-generated snapshot file that contain all the blocks and transactions. This method is considerably faster than the previous method, but can still take order of hours to days to complete.
Follow steps in: Connecting to mainnet using a pre-created snapshot.
The relay is a REST API service layer that runs in front of the blockchain node and exposes a limited set of important APIs that clients can then call. The first step is to read the documentation of the relay.
In the folder where the node is located, as shown in the first step, there will be two relay config files, one for Windows and one for Linux. Edit the appropriate file to your requirements, according to the documentation shared in the previous step. You may also opt to run with the default configuration, which is useful if you are running both the Node and the relay in the same machine.
Windows
```
relay-config-windows.json
```
Mac
```
relay-config-linux.json
```
Start the relay by running the following command while you are in the same directory as the blockchain node. Please wait for the relay to process all blocks till the latest block.
Windows
```
relay.exe relay-config-windows.json
```
Linux
Replace $HOME/dp with the directory where the relay is located.
```
export LD_LIBRARY_PATH=$HOME/dp
```
```
./relay relay-config-linux.json
```
Review the SDK documentation and the SDK examples. You can configure the SDK to connect to the relay started in the previous step using the following code; if you edited the default config to change ports, please change the ports accordingly. The SDK client can also call into the relay over the network to a different server or machine, in which case you would need to provide the appropriate DNS or IP addresses and open appropriate firewall ports.
Initialization Code
The first and second parameters to the qcsdk.Config should map to the ports used in the relay config in the step for starting the relay.
```
var clientConfigVal = new qcsdk.Config("http://127.0.0.1:9090", "http://127.0.0.1:9091", 123123, "", "");
```