feat: add HTTP example

typescript/examples/x402-http-client/README.md

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+# x402 HTTP Client Example
+
+Demonstrates using Ampersend with the standard x402 fetch wrapper for HTTP API payments.
+
+## Overview
+
+This example shows how to add Ampersend payment authorization to x402-protected HTTP APIs. It uses the same `@x402/fetch` wrapper as the official x402 SDK, with minimal additions for Ampersend integration.
+
+**Compare with the [official x402-v2 fetch example](https://github.com/coinbase/x402/tree/main/examples/typescript/clients/fetch) to see the minimal setup difference.**
+
+## Installation
+
+```bash
+# From the ampersend-examples root
+pnpm install
+
+# Or install this package specifically
+cd typescript/examples/x402-http-client
+pnpm install
+```
+
+## Usage
+
+Set your private key and run:
+
+```bash
+PRIVATE_KEY=0x... pnpm dev
+```
+
+## How It Works
+
+The example demonstrates the core Ampersend pattern for HTTP payments:
+
+```typescript
+import { x402Client, wrapFetchWithPayment } from "@x402/fetch"
+import { AccountWallet, NaiveTreasurer } from "@ampersend_ai/ampersend-sdk"
+import { wrapWithAmpersend } from "@ampersend_ai/ampersend-sdk/x402"
+
+// --- Standard x402 setup (same as official example) ---
+const client = new x402Client()
+
+// --- Ampersend additions (replaces registerExactEvmScheme) ---
+const wallet = AccountWallet.fromPrivateKey(privateKey)
+const treasurer = new NaiveTreasurer(wallet)  // Decides whether to pay
+wrapWithAmpersend(client, treasurer, ["base", "base-sepolia"])
+
+// --- Use it (identical to official example) ---
+const fetchWithPayment = wrapFetchWithPayment(fetch, client)
+const response = await fetchWithPayment("https://paid-api.example.com/resource")
+```
+
+## Comparison with x402-v2
+
+| x402-v2 Official | Ampersend | Purpose |
+|------------------|-----------|---------|
+| `privateKeyToAccount(key)` | `AccountWallet.fromPrivateKey(key)` | Wallet creation |
+| `registerExactEvmScheme(client, { signer })` | `wrapWithAmpersend(client, treasurer, networks)` | Payment registration |
+| - | `new NaiveTreasurer(wallet)` | Payment authorization |
+
+The key difference: Ampersend uses a **Treasurer** pattern that allows sophisticated payment policies (budgets, approvals, limits) instead of auto-signing everything.
+
+## Development
+
+```bash
+pnpm build        # Build TypeScript
+pnpm dev          # Run with tsx
+pnpm lint         # Run ESLint
+pnpm format       # Check formatting
+```
+
+## Project Structure
+
+```
+src/
+└── index.ts    # Main example demonstrating HTTP payment flow
+```
+
+## Learn More
+
+- [HTTP x402 Adapter Documentation](https://github.com/edgeandnode/ampersend-sdk/tree/main/typescript/packages/ampersend-sdk/src/x402/http)
+- [Ampersend SDK Documentation](https://github.com/edgeandnode/ampersend-sdk)
+- [x402 Protocol](https://github.com/coinbase/x402)

typescript/examples/x402-http-client/eslint.config.mjs

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+import config from "../../eslint.config.mjs"
+
+export default config

typescript/examples/x402-http-client/package.json

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+{
+  "name": "@edgeandnode/x402-http-client-example",
+  "description": "Example x402 HTTP client with Ampersend payment handling",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "tsx src/index.ts",
+    "build": "tsc -b tsconfig.json",
+    "clean": "rm -rf dist .tsbuildinfo",
+    "lint": "eslint .",
+    "lint:fix": "eslint . --fix",
+    "format": "prettier . --check --ignore-path ../../.prettierignore",
+    "format:fix": "prettier . --write --list-different --ignore-path ../../.prettierignore"
+  },
+  "dependencies": {
+    "@ampersend_ai/ampersend-sdk": "^0.0.3",
+    "@modelcontextprotocol/sdk": "github:edgeandnode/mcp-typescript-sdk#2de06543904483073d8cc13db1d0e08e16601081",
+    "@x402/core": "^2.1.0",
+    "@x402/fetch": "^2.1.0",
+    "fastmcp": "github:edgeandnode/fastmcp#6446ea7b56eb291a6d4d7321e4a41ff0aacba1ef",
+    "x402": "^0.6.6"
+  },
+  "devDependencies": {
+    "tsx": "^4.21.0"
+  }
+}

typescript/examples/x402-http-client/src/index.ts

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+import { x402Client, wrapFetchWithPayment } from "@x402/fetch"
+import { AccountWallet, NaiveTreasurer } from "@ampersend_ai/ampersend-sdk"
+import { wrapWithAmpersend } from "@ampersend_ai/ampersend-sdk/x402"
+
+async function main() {
+  const privateKey = process.env.PRIVATE_KEY as `0x${string}`
+  if (!privateKey) {
+    console.error("PRIVATE_KEY environment variable is required")
+    process.exit(1)
+  }
+
+  // --- Standard x402 setup (same as official example) ---
+  const client = new x402Client()
+
+  // --- Ampersend additions (replaces registerExactEvmScheme) ---
+  const wallet = AccountWallet.fromPrivateKey(privateKey)
+  const treasurer = new NaiveTreasurer(wallet) // Decides whether to pay
+  wrapWithAmpersend(client, treasurer, ["base", "base-sepolia"])
+
+  // --- Use it (identical to official example) ---
+  const fetchWithPayment = wrapFetchWithPayment(fetch, client)
+  const response = await fetchWithPayment("https://paid-api.example.com/resource")
+  console.log("Response status:", response.status)
+}
+
+main().catch(console.error)

typescript/examples/x402-http-client/tsconfig.json

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+{
+  "extends": "../../tsconfig.base.jsonc",
+  "include": ["src/**/*"],
+  "compilerOptions": {
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "types": ["node"]
+  }
+}