> For the complete documentation index, see [llms.txt](https://iqlabs.gitbook.io/iqlabs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://iqlabs.gitbook.io/iqlabs/developers-info/setting-up-the-sdk.md).

# setting up the SDK

[What is Linked List?](https://www.youtube.com/watch?v=F8AbOfQwl1c)

[What is PDA?](https://solana.com/docs/core/pda)

1. Type npm install "<https://github.com/IQCoreTeam/code_in_sdk.git>" to install IQ sdk.

### Features

* **Inscribe data** (`codeIn`, `codeInAfterErr`)
* **Fetch data** (`readCode`, `fetchLargeFileAndDoCache`)
* **Validate local data against on-chain state** (`dataValidation`)
* **Account initialization helper** (`userInit`)

### Step1. Make .env file&#x20;

```
SIGNER_PRIVATE_KEY="your_base58_encoded_private_key"
RPC="https://your.solana.rpc.endpoint"
```

### Step2. Account initialization (required on first use per wallet)

Before writing data for a wallet, you **must initialize the user account** on-chain:

[Why we need to make PDA?](https://app.gitbook.com/o/V0P8Hrpy6nw037kPupYK/s/1PRdz0H8Z8O6nP9PTXfE/~/changes/32/developers-info/setting-up-the-sdk/detail-how-code-in-works-with-2-pdas)

```
import iqsdk from 'iq-sdk';

await iqsdk.userInit();
```

### Write data to chain

```
import iqsdk from 'iq-sdk';

await iqsdk.codeIn("your data here", "manual_datatype", "your_handle");
```

Write Data From Middle:&#x20;

```
import iqsdk from 'iq-sdk';

const result = await iqsdk.codeInAfterErr(brokeNum, beforeHash, data, type, handle);

```

***

### Fetch data from chain

```
import iqsdk from 'iq-sdk';

const result = await iqsdk.readCode("your_transaction_id");
```

Or fetch and cache large files:

```
import iqsdk from 'iq-sdk';

const content = await iqsdk.fetchLargeFileAndDoCache("your_transaction_id");
```

***

#### Validate local data

```
import iqsdk from 'iq-sdk';

await iqsdk.dataValidation("transaction_id", "localDataString")
```

&#x20;