> ## Documentation Index
> Fetch the complete documentation index at: https://sigil-10dddbf2.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Installation

> Install the Sigil SDK and set up your Solana connection.

## Requirements

* Node.js 18+ or Bun
* A Solana wallet (keypair) with SOL on devnet for account rent
* A Solana RPC endpoint (Helius, QuickNode, or the public devnet URL)

## Install the SDK

<CodeGroup>
  ```bash npm theme={null}
  npm install @sigil-xyz/sdk @coral-xyz/anchor @solana/web3.js bn.js
  ```

  ```bash bun theme={null}
  bun add @sigil-xyz/sdk @coral-xyz/anchor @solana/web3.js bn.js
  ```

  ```bash pnpm theme={null}
  pnpm add @sigil-xyz/sdk @coral-xyz/anchor @solana/web3.js bn.js
  ```
</CodeGroup>

`@sigil-xyz/sdk` has peer dependencies on `@coral-xyz/anchor` and `@solana/web3.js` — install them explicitly alongside the SDK.

## Install the x402 middleware

If you are building a service that gates API endpoints by Sigil credentials:

<CodeGroup>
  ```bash npm theme={null}
  npm install @sigil-xyz/x402
  ```

  ```bash bun theme={null}
  bun add @sigil-xyz/x402
  ```
</CodeGroup>

The package exposes two subpaths:

| Import                 | Use for                                   |
| ---------------------- | ----------------------------------------- |
| `@sigil-xyz/x402`      | Express middleware + agent header builder |
| `@sigil-xyz/x402/next` | Next.js App Router wrapper                |

## Set up a connection

```ts theme={null}
import { Connection } from '@solana/web3.js'

const connection = new Connection('https://api.devnet.solana.com', 'confirmed')
```

<Note>
  Use a dedicated RPC URL from Helius or QuickNode in production. The public devnet endpoint is rate-limited.
</Note>

## Construct a SigilClient

`SigilClient` takes a `Connection` and a wallet that can sign transactions.

```ts theme={null}
import { SigilClient } from '@sigil-xyz/sdk'
import { Connection, Keypair } from '@solana/web3.js'
import { readFileSync } from 'fs'

const connection = new Connection('https://api.devnet.solana.com', 'confirmed')

// Load your principal keypair
const secret = JSON.parse(readFileSync('/path/to/keypair.json', 'utf-8'))
const keypair = Keypair.fromSecretKey(Uint8Array.from(secret))

const client = new SigilClient({
  connection,
  wallet: {
    publicKey: keypair.publicKey,
    signTransaction: async (tx) => { tx.sign(keypair); return tx },
    signAllTransactions: async (txs) => { txs.forEach(tx => tx.sign(keypair)); return txs },
  },
})
```

The `wallet` field accepts any object with `publicKey`, `signTransaction`, and `signAllTransactions` — this matches the `AnchorProvider["wallet"]` interface. In a browser, pass a wallet adapter directly.