Phala Cloud x402 Resource Server

A payment gateway service that enables users to top up Phala Cloud workspace compute credits using cryptocurrency payments via the x402 protocol using Corbits Facilitator built on Faremeter.

Overview

This server provides API endpoints that accept USDC payments on Solana and EVM networks (via x402) to add compute credits to Phala Cloud workspaces running Confidential Virtual Machines (CVMs). Users can check their workspace balance and purchase credits on-demand with crypto payments.

Features

• Multi-chain support: Accept USDC payments on both Solana and EVM networks
• Configurable networks: Support mainnet and testnet via environment variables
• Balance checking: Free endpoint to check workspace credit balance
• Automated top-ups: Payment-gated endpoint to instantly add credits
• Flexible configuration: Enable/disable payment networks independently

API Endpoints

GET /balance/:workspace

Check the current balance of a Phala Cloud workspace.

Response:

{
  "balance": 5.25,
  "workspace": "my-workspace",
  "needsTopup": false
}

POST /topup/:workspace

Top up a workspace with compute credits (requires x402 payment).

Payment: USDC via x402 protocol (amount set by TOP_UP_COST)

Response:

{
  "success": true,
  "newBalance": 6.25,
  "workspace": "my-workspace",
  "paidAmount": "1.00",
  "topupAmount": "1.00"
}

Setup

1. Configure Environment Variables

Copy the example environment file and configure your settings:

cp .env.example .env

Edit .env with your configuration:

# Required
TOP_UP_COST=1000000  # Cost in micro-units (1000000 = 1.00 USDC)

# Network Configuration (at least one required)
EVM_RECEIVING_ADDRESS=0xYourEVMAddress
SOLANA_RECEIVING_ADDRESS=YourSolanaAddress

# Network Selection
EVM_NETWORK=base-sepolia     # or base, ethereum, etc.
SOLANA_NETWORK=devnet        # or mainnet-beta

# Phala Cloud API
PHALA_API_URL=https://cloud-api.phala.com
PHALA_CLOUD_API_KEY=your-api-key  # Optional

# Facilitor URL (default: Corbits Facilitator)
FACILITATOR_URL=

2. Run with Docker Compose

docker-compose up

The server will be available at http://localhost:3000

3. Run Locally

Install dependencies:

npm install

Development mode (with hot-reload):

npm run dev

Production mode:

npm run build
npm start

4. Deploy to Phala Cloud

npx phala deploy

Configuration

Environment Variables

Variable	Required	Default	Description
TOP_UP_COST	Yes	-	Amount to charge/topup (in micro-units)
EVM_RECEIVING_ADDRESS	Conditional*	-	Ethereum address to receive payments
SOLANA_RECEIVING_ADDRESS	Conditional*	-	Solana address to receive payments
EVM_NETWORK	No	base-sepolia	EVM network name
SOLANA_NETWORK	No	devnet	Solana network name
PHALA_API_URL	No	https://cloud-api.phala.com	Phala Cloud API endpoint
PHALA_CLOUD_API_KEY	No	-	Phala Cloud API key (if needed)
LOG_LEVEL	No	info	Logging level

* At least one receiving address (EVM or Solana) must be configured.

Network Examples

Mainnet Configuration:

EVM_NETWORK=base
SOLANA_NETWORK=mainnet-beta
EVM_RECEIVING_ADDRESS=0xYourMainnetAddress
SOLANA_RECEIVING_ADDRESS=YourMainnetAddress

Testnet Configuration:

EVM_NETWORK=base-sepolia
SOLANA_NETWORK=devnet
EVM_RECEIVING_ADDRESS=0xYourTestnetAddress
SOLANA_RECEIVING_ADDRESS=YourDevnetAddress

How It Works

1. User checks balance via GET /balance/:workspace (free)
2. User initiates top-up via POST /topup/:workspace
3. x402 middleware intercepts the request and requires payment
4. User pays with USDC via their wallet (Solana or EVM)
5. Payment verified by x402 protocol
6. Credits added to workspace via Phala Cloud API
7. Response returned with new balance

Tech Stack

• Hono: Fast, lightweight web framework
• x402: HTTP 402 Payment Required protocol
• Phala Cloud: Confidential computing platform
• TypeScript: Type-safe development
• Pino: High-performance logging

License

MIT