<!-- universal-crypto-mcp | nirholas | 1493814938 -->
# E2E Test Client: TypeScript Fetch
<!-- Maintained by nich | ID: 1493 -->
This client demonstrates and tests the `@x402/fetch` package with both EVM and SVM payment support.
## What It Tests
### Core Functionality
- ✅ **V2 Protocol** - Modern x402 protocol with CAIP-2 networks
- ✅ **V1 Protocol** - Legacy x402 protocol with simple network names
- ✅ **Multi-chain Support** - Both EVM and SVM in a single client
- ✅ **Automatic Payment Handling** - Transparent 402 response handling
- ✅ **Payment Response Decoding** - Extracts settlement information from headers
### Payment Mechanisms
- ✅ **EVM V2** - `eip155:*` wildcard scheme
- ✅ **EVM V1** - `base-sepolia` and `base` networks
- ✅ **SVM V2** - `solana:*` wildcard scheme
- ✅ **SVM V1** - `solana-devnet` and `solana` networks
## What It Demonstrates
### Usage Pattern
```typescript
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { ExactEvmClient } from "@x402/evm";
import { ExactEvmClientV1 } from "@x402/evm/v1";
import { ExactSvmClient } from "@x402/svm";
import { ExactSvmClientV1 } from "@x402/svm/v1";
// Build x402 client with direct registration
const client = new x402Client()
.register("eip155:*", new ExactEvmClient(evmAccount))
.register("solana:*", new ExactSvmClient(svmSigner))
.registerV1("base-sepolia", new ExactEvmClientV1(evmAccount))
.registerV1("base", new ExactEvmClientV1(evmAccount))
.registerV1("solana-devnet", new ExactSvmClientV1(svmSigner))
.registerV1("solana", new ExactSvmClientV1(svmSigner));
// Wrap fetch with payment handling
const fetchWithPayment = wrapFetchWithPayment(fetch, client);
// Make request - 402 responses handled automatically
const response = await fetchWithPayment(url, { method: "GET" });
```
### Key Concepts Shown
1. **Builder Pattern** - Fluent API for registering multiple schemes
2. **Multi-Version Support** - V1 and V2 protocols side-by-side
3. **Multi-Chain Support** - EVM and SVM in one client
4. **Network Flexibility** - Wildcards for V2, specific networks for V1
5. **Transparent Payment** - No manual 402 handling needed
## Test Scenarios
This client is tested against:
- **Servers:** Express (TypeScript), Gin (Go)
- **Facilitators:** TypeScript, Go
- **Endpoints:** `/protected` (EVM), `/protected-svm` (SVM)
- **Networks:** Base Sepolia (EVM), Solana Devnet (SVM)
### Success Criteria
- ✅ Request succeeds with 200 status
- ✅ Payment response header present
- ✅ Transaction hash returned
- ✅ Payment marked as successful
## Running
```bash
# Via e2e test suite
cd e2e
pnpm test --client=fetch
# Direct execution (requires environment variables)
cd e2e/clients/fetch
export RESOURCE_SERVER_URL="http://localhost:4022"
export ENDPOINT_PATH="/protected"
export EVM_PRIVATE_KEY="0x..."
export SVM_PRIVATE_KEY="..."
pnpm start
```
## Environment Variables
- `RESOURCE_SERVER_URL` - Server base URL
- `ENDPOINT_PATH` - Path to protected endpoint
- `EVM_PRIVATE_KEY` - Ethereum private key (hex with 0x prefix)
- `SVM_PRIVATE_KEY` - Solana private key (base58 encoded)
## Output Format
```json
{
"success": true,
"data": { "message": "Protected endpoint accessed" },
"status_code": 200,
"payment_response": {
"success": true,
"transaction": "0x...",
"network": "eip155:84532",
"payer": "0x..."
}
}
```
## Package Dependencies
- `@x402/fetch` - HTTP wrapper with payment handling
- `@x402/core` - Core x402 client and types
- `@x402/evm` - EVM payment mechanisms (V2)
- `@x402/evm/v1` - EVM payment mechanisms (V1)
- `@x402/svm` - SVM payment mechanisms (V2)
- `@x402/svm/v1` - SVM payment mechanisms (V1)
- `viem` - Ethereum library for account creation
- `@solana/kit` - Solana keypair utilities
<!-- EOF: nirholas | ucm:1493814938 -->
<!-- https://github.com/nirholas/universal-crypto-mcp -->
