# Configuration

For obtaining the API keys for blockchain access and setting the correct environment variables, please consult [this section](http://127.0.0.1:5000/o/mTcjMqA4ylf55anucjH8/s/zQlpIJEeu8x5yl0OLuXn/) first and proceed with the next steps.

### Create a directory

Let's start with creating a working directory where we store the environment variable file, configuration files, and the scripts.

```bash
mkdir my-ocean-project
cd my-ocean-project
```

### Create a `.env` file

In the working directory create a `.env` file. The content of this file will store the values for the following variables:

<table><thead><tr><th width="235.47193347193348">Variable name</th><th width="421">Description</th><th>Required</th></tr></thead><tbody><tr><td><strong>OCEAN_NETWORK</strong></td><td>Name of the network where the Ocean Protocol's smart contracts are deployed.</td><td>Yes</td></tr><tr><td><strong>OCEAN_NETWORK_URL</strong></td><td>The URL of the Ethereum node (along with API key for non-local networks)**</td><td>Yes</td></tr><tr><td><strong>PRIVATE_KEY</strong></td><td>The private key of the account which you want to use. A private key is made up of 64 hex characters. Make sure you have sufficient balance to pay for the transaction fees.</td><td>Yes</td></tr><tr><td><strong>AQUARIUS_URL</strong></td><td>The URL of the Aquarius. This value is needed when reading an asset from off-chain store.</td><td>No</td></tr><tr><td><strong>PROVIDER_URL</strong></td><td>The URL of the Provider. This value is needed when publishing a new asset or update an existing asset.</td><td>No</td></tr></tbody></table>

{% hint style="info" %}
Treat this file as a secret and do not commit this file to git or share the content publicly. If you are using git, then include this file name in `.gitignore` file.
{% endhint %}

The below tabs show partially filled `.env` file content for some of the supported networks.

{% tabs %}
{% tab title="Mainnet" %}
{% code title=".env" %}

```bash
# Mandatory environment variables

OCEAN_NETWORK=mainnet
OCEAN_NETWORK_URL=<replace this>
PRIVATE_KEY=<secret>

# Optional environment variables

AQUARIUS_URL=https://v4.aquarius.oceanprotocol.com/
PROVIDER_URL=https://v4.provider.oceanprotocol.com
```

{% endcode %}
{% endtab %}

{% tab title="Polygon" %}
{% code title=".env" %}

```bash
# Mandatory environment variables

OCEAN_NETWORK=polygon
OCEAN_NETWORK_URL=<replace this>
PRIVATE_KEY=<secret>

# Optional environment variables

AQUARIUS_URL=https://v4.aquarius.oceanprotocol.com/
PROVIDER_URL=https://v4.provider.oceanprotocol.com
```

{% endcode %}
{% endtab %}

{% tab title="Local (using Barge)" %}
{% code title=".env" %}

```bash
# Mandatory environment variables
OCEAN_NETWORK=development
OCEAN_NETWORK_URL=http://172.15.0.3:8545/
AQUARIUS_URL=http://172.15.0.5:5000
PROVIDER_URL=http://172.15.0.4:8030

# Replace PRIVATE_KEY if needed
PRIVATE_KEY=0xc594c6e5def4bab63ac29eed19a134c130388f74f019bc74b8f4389df2837a58
```

{% endcode %}
{% endtab %}
{% endtabs %}

Replace `<replace this>` with the appropriate values. You can see all the networks configuration on Oceanjs' [config helper](https://github.com/oceanprotocol/ocean.js/blob/main/src/config/ConfigHelper.ts#L42).

### Setup dependencies

In this step, all required dependencies will be installed.

### Installation & Usage

Let's install Ocean.js library into your current project by running:

{% tabs %}
{% tab title="Terminal" %}
{% code overflow="wrap" %}

```bash
npm init
npm i @oceanprotocol/lib@latest dotenv crypto-js ethers@5.7.4 @truffle/hdwallet-provider
```

{% endcode %}
{% endtab %}
{% endtabs %}

### Create a configuration file

A configuration file will read the content of the `.env` file and initialize the required configuration objects which will be used in the further tutorials. The below scripts creates a Web3 wallet instance and an Ocean's configuration object.

Create the configuration file in the working directory i.e. at the same path where the `.env` is located.

{% tabs %}
{% tab title="config.js" %}
{% code title="config.js" %}

```javascript
require("dotenv").config();
const {
	Aquarius,
	ConfigHelper,
	configHelperNetworks,
} = require("@oceanprotocol/lib");
const ethers = require("ethers");
import fs from "fs";
import { homedir } from "os";

async function oceanConfig() {
	const provider = new ethers.providers.JsonRpcProvider(
		process.env.OCEAN_NETWORK_URL || configHelperNetworks[1].nodeUri
	);
	const publisherAccount = new ethers.Wallet(process.env.PRIVATE_KEY, provider);

	let oceanConfig = new ConfigHelper().getConfig(
		parseInt(String((await publisherAccount.provider.getNetwork()).chainId))
	);
	const aquarius = new Aquarius(oceanConfig?.metadataCacheUri);

	// If using local development environment, read the addresses from local file.
	// The local deployment address file can be generated using barge.
	if (process.env.OCEAN_NETWORK === "development") {
		const addresses = JSON.parse(
			// eslint-disable-next-line security/detect-non-literal-fs-filename
			fs.readFileSync(
				process.env.ADDRESS_FILE ||
					`${homedir}/.ocean/ocean-contracts/artifacts/address.json`,
				"utf8"
			)
		).development;

		oceanConfig = {
			...oceanConfig,
			oceanTokenAddress: addresses.Ocean,
			fixedRateExchangeAddress: addresses.FixedPrice,
			dispenserAddress: addresses.Dispenser,
			nftFactoryAddress: addresses.ERC721Factory,
			opfCommunityFeeCollector: addresses.OPFCommunityFeeCollector,
		};
	}

	oceanConfig = {
		...oceanConfig,
		publisherAccount: publisherAccount,
		consumerAccount: publisherAccount,
		aquarius: aquarius,
	};

	return oceanConfig;
}

module.exports = {
	oceanConfig,
};
```

{% endcode %}
{% endtab %}
{% endtabs %}

Now you have set up the necessary files and configurations to interact with Ocean Protocol's smart contracts using ocean.js. You can proceed with further tutorials or development using these configurations.