@402md/mcp

Installation

npm install -g @402md/mcp

Configuration

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "402md": {
      "command": "402md-mcp",
      "env": {
        "WALLET_PRIVATE_KEY": "0xabc...",
        "NETWORK": "base"
      }
    }
  }
}

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "402md": {
      "command": "402md-mcp",
      "env": {
        "WALLET_PRIVATE_KEY": "0xabc...",
        "NETWORK": "base"
      }
    }
  }
}

Any MCP-compatible client can connect via stdio:

WALLET_PRIVATE_KEY=0xabc... NETWORK=base 402md-mcp

Environment variables

Variable	Required	Default	Description
`WALLET_PRIVATE_KEY`	Yes	—	Hex private key for USDC wallet
`NETWORK`	No	`base`	`base` or `base-sepolia`
`API_BASE_URL`	No	`https://api.402.md`	402.md API endpoint

Tools

`search_skills`

Search 402.md for available skills (APIs, SaaS, products, services).

Parameter	Type	Required	Description
`query`	`string`	Yes	Search query

Returns: list of matching skills with name, description, price, and type.

`call_api`

Call a paid API with automatic x402 payment.

Parameter	Type	Required	Description
`skill`	`string`	Yes	Skill name or ID
`path`	`string`	Yes	API endpoint path
`method`	`string`	No	HTTP method. Defaults to `GET`
`body`	`string`	No	JSON request body as string

Returns: API response data.

Subscribe to a SaaS service.

Parameter	Type	Required	Description
`skill`	`string`	Yes	Skill name or ID

Returns: ticket JWT, access URL, and expiration date.

`buy_product`

Purchase a product.

Parameter	Type	Required	Description
`skill`	`string`	Yes	Skill name or ID
`path`	`string`	Yes	Product endpoint path
`quantity`	`number`	No	Number of items. Defaults to `1`
`shipping`	`object`	No	Shipping address (name, address, city, state, zip, country)

Returns: order ID, tracking URL, and total amount.

`check_balance`

Check the USDC wallet balance. No parameters.

Returns:

Field	Type	Description
`balance`	`string`	USDC balance
`token`	`string`	`"USDC"`
`network`	`string`	Network name
`wallet`	`string`	Wallet address
`spentToday`	`number`	Amount spent today
`dailyBudget`	`string`	Daily budget limit or `"unlimited"`
`perTransactionLimit`	`string`	Per-tx limit or `"unlimited"`

`get_orders`

View recent purchases and orders. No parameters.

Returns: list of recent transactions with status.

Programmatic usage

import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
import { register402Tools } from '@402md/mcp'

const server = new McpServer({ name: 'my-agent', version: '1.0.0' })

register402Tools(server, {
  privateKey: process.env.WALLET_PRIVATE_KEY!,
  network: 'base',
  apiBaseUrl: 'https://api.402.md',
  budget: {
    daily: '100.00',
    perTransaction: '50.00'
  }
})

McpConfig

Field	Type	Required	Description
`privateKey`	`string`	Yes	Wallet private key
`network`	`'base'` \| `'base-sepolia'`	No	Network. Defaults to `'base'`
`apiBaseUrl`	`string`	No	API URL. Defaults to `'https://api.402.md'`
`budget.daily`	`string`	No	Daily spending limit
`budget.perTransaction`	`string`	No	Per-transaction limit

Example conversation

User: Find me an API that can analyze sentiment and call it with "I love this product"

Claude (using 402.md MCP tools):

Calls search_skills with query "sentiment analysis"
Finds "sentiment-api" at $0.05/call
Calls call_api with skill "sentiment-api", path "/analyze", body {"text": "I love this product"}
Auto-pays $0.05 USDC via x402
Returns: { "sentiment": "positive", "score": 0.95 }

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