reversesandbox-mcp

MCP server for ReverseSandbox — pay for x402 services without managing crypto wallets.

ReverseSandbox lets AI agents pay for x402 pay-per-use API services (web search, scraping, screenshots) using a simple API key and USD balance. No wallets, no tokens, no bridging — just fund your account and your agent can pay for any x402-enabled service automatically.

Quick Start

1. Get an API key at reversesandbox.com/dashboard
2. Add funds to your account balance
3. Configure the MCP in your AI client (see below)

Configuration

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "reversesandbox": {
      "command": "npx",
      "args": ["-y", "reversesandbox-mcp"],
      "env": {
        "RS_API_KEY": "your-api-key-here"
      }
    }
  }
}

Claude Code

claude mcp add reversesandbox -- npx -y reversesandbox-mcp

Then set your API key as an environment variable:

export RS_API_KEY="your-api-key-here"

OpenClaw

{
  "mcpServers": {
    "reversesandbox": {
      "command": "npx",
      "args": ["-y", "reversesandbox-mcp"],
      "env": {
        "RS_API_KEY": "your-api-key-here"
      }
    }
  }
}

Available Tools

pay

Sign an x402 payment to access a pay-per-use API service. Call this when you receive a 402 Payment Required response. Returns a payment header to include in your retry request.

Parameters:

• to (string, required) — Recipient address (0x-prefixed Ethereum address from the 402 response)
• amount (string, required) — Payment amount in USD (e.g. "0.002", from the 402 response)
• network (string, optional, default: "base") — Network name (base, polygon, arbitrum)

get_balance

Check your remaining ReverseSandbox balance.

get_usage

View recent payment history showing services used, amounts paid, and timestamps.

Parameters:

• limit (number, optional, default: 20) — Number of records to return

Example Workflow

Here's how an agent uses ReverseSandbox to pay for an x402-protected search service:

1. Agent makes a request to an x402-enabled search API:

   GET https://api.example.com/search?q=latest+AI+news

2. Service returns 402 Payment Required with payment details:

   {
     "payTo": "0xabc...123",
     "maxAmountRequired": "0.002",
     "network": "base"
   }

3. Agent calls the pay tool with the details from the 402 response:

   {
     "to": "0xabc...123",
     "amount": "0.002",
     "network": "base"
   }

4. Tool returns a payment header:

   Payment signed successfully.
   Cost: $0.002
   Remaining balance: $9.998
   
   To complete your request, retry it with this header:
   X-PAYMENT: eyJhbGciOi...

5. Agent retries the request with the payment header:

   GET https://api.example.com/search?q=latest+AI+news
   X-PAYMENT: eyJhbGciOi...

6. Service validates payment and returns results.

Pricing

| Service | Cost per request | |--------------|-----------------| | Web Search | $0.002 | | Web Scrape | $0.005 | | Screenshot | $0.002 |

Environment Variables

| Variable | Required | Default | Description | |---------------|----------|----------------------------------|----------------------| | RS_API_KEY | Yes | — | Your API key | | RS_API_URL | No | https://www.reversesandbox.com | API base URL |

License

MIT