> ## Documentation Index
> Fetch the complete documentation index at: https://docs.xenarch.com/llms.txt
> Use this file to discover all available pages before exploring further.

# TypeScript SDK

> @xenarch/core — TypeScript & Node.js SDK for x402 payments, AI agent integration, and publisher middleware. USDC micropayments on Base.

## Installation

```bash theme={null}
npm install @xenarch/core
```

Published on [npm](https://www.npmjs.com/package/@xenarch/core). Used internally by the MCP server and CLI.

## Configuration

```typescript theme={null}
import { loadConfig, createSigner } from "@xenarch/core";

const { config } = await loadConfig();
const signer = createSigner(config);

console.log(config.network);  // "base" or "base-sepolia"
```

**Config loading priority:**

1. Environment variables (`XENARCH_PRIVATE_KEY`, `XENARCH_RPC_URL`, etc.)
2. `~/.xenarch/config.json`
3. `~/.xenarch/wallet.json`
4. Auto-generate wallet on first use

## Gate checking

```typescript theme={null}
import { fetchGate, fetchGateByDomain } from "@xenarch/core";

// Check by URL (HTTP request, looks for 402)
const result = await fetchGate("https://example.com/premium");
if (result.gate) {
  console.log(result.gate.price_usd);  // "0.003"
}

// Check by domain (platform API)
const gate = await fetchGateByDomain(
  "https://xenarch.dev",
  "example.com"
);
```

## Payment execution

```typescript theme={null}
import { executePayment, verifyPayment } from "@xenarch/core";

// Execute USDC payment on Base
const result = await executePayment(gate, signer, usdcAddress);
console.log(result.txHash);       // "0x..."
console.log(result.blockNumber);  // 28451023

// Verify and get access token
const { access_token, expires_at } = await verifyPayment(
  gate.verify_url,
  result.txHash
);
```

## Payment history

```typescript theme={null}
import { getPaymentHistory } from "@xenarch/core";

const history = await getPaymentHistory(
  "https://xenarch.dev",
  walletAddress,
  { domain: "example.com", limit: 10 }
);
```

## Types

```typescript theme={null}
interface XenarchConfig {
  privateKey: string;
  rpcUrl: string;
  apiBase: string;
  network: "base" | "base-sepolia";
  autoApproveMaxUsd?: number;
  allowedDomains?: string[];
  blockedDomains?: string[];
}

interface GateResponse {
  xenarch: boolean;
  gate_id: string;
  price_usd: string;
  splitter: string;
  collector: string;
  network: string;
  asset: string;
  protocol: string;
  verify_url: string;
  expires: string;
}

interface PaymentResult {
  txHash: string;
  blockNumber: number;
}

interface PaymentHistoryItem {
  url: string;
  domain: string;
  amount_usd: string;
  tx_hash: string;
  paid_at: string;
}
```

## Contract constants

```typescript theme={null}
// Base Mainnet
const USDC_BASE = "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913";
const SPLITTER_MAINNET = "0xC6D3a6B6fcCD6319432CDB72819cf317E88662ae";

// Base Sepolia
const SPLITTER_SEPOLIA = "0x7ecfe8f83eab6ba170063d1f1fe7c33695a9ce1d";
const MOCK_USDC_SEPOLIA = "0xc5aDdd66Da733101A5468857Aa3C6689Af9d1DDc";
```