@pay-skill/mcp
MCP server for Pay — USDC payments for AI agents on Base.
Gives any MCP-compatible client (Claude Desktop, Cursor, VS Code, custom frameworks) the full power of Pay: direct payments, tabs, x402 paywalls, service discovery, and wallet management. No CLI binary needed.
Setup
Claude Desktop
Add to claude_desktop_config.json:
{
"mcpServers": {
"pay": {
"command": "npx",
"args": ["-y", "@pay-skill/mcp"]
}
}
}
VS Code / Cursor
Add to .vscode/mcp.json:
{
"servers": {
"pay": {
"command": "npx",
"args": ["-y", "@pay-skill/mcp"]
}
}
}
Claude Code
claude mcp add pay -- npx -y @pay-skill/mcp
That's it. On first run, the server generates a wallet and stores it in the OS keychain (Windows Hello, macOS Keychain, Linux Secret Service). Subsequent runs load it automatically.
Configuration
| Env Var | Required | Default | Description |
|---|---|---|---|
PAYSKILL_SIGNER_KEY |
No | — | Optional override. Raw hex key or .enc keystore password. Not needed for normal use. |
PAY_NETWORK |
No | mainnet |
mainnet (Base) or testnet (Base Sepolia) |
Key Resolution (checked in order)
- OS keychain (default) — Loads from the OS credential store via
keytar. On first run, a new keypair is generated and stored automatically. - Encrypted keystore — If
~/.pay/keys/default.encexists,PAYSKILL_SIGNER_KEYis used as the decryption password. - Raw hex key — If
PAYSKILL_SIGNER_KEYis a 64-char hex string, it's used directly. For dev/testing or importing an existing wallet. - Auto-generate — If none of the above, generates a new keypair and stores it in the OS keychain.
Diagnostic Check
Verify everything is configured correctly:
npx @pay-skill/mcp --check
Output:
pay-mcp diagnostic check
network: Base (chain 8453)
api: https://pay-skill.com/api/v1
wallet: 0x1234...
key: keychain
server: OK (router: 0xABCD...)
auth: OK (balance: $50.00)
All checks passed. MCP server is ready.
Tools (15)
Payments
| Tool | Description |
|---|---|
pay_send |
Direct USDC payment ($1 min). Confirmation thresholds: <$10 auto, $10-100 plan, >$100 explicit. |
pay_request |
HTTP request with x402 auto-payment. Handles 402 detection, direct/tab settlement, price skepticism. |
Tabs (metered accounts)
| Tool | Description |
|---|---|
pay_tab_open |
Open pre-funded tab ($5 min, $50 recommended). Provider charges per-call. |
pay_tab_close |
Close tab. Returns distribution breakdown (provider 99%, fee 1%, agent remainder). |
pay_tab_charge |
Charge against open tab (provider only). |
pay_tab_topup |
Add funds to open tab (agent only). |
pay_tab_list |
List tabs with idle/low-balance flags. |
Wallet
| Tool | Description |
|---|---|
pay_status |
Balance, locked/available funds, actionable suggestions. |
pay_fund |
Generate 1-hour funding link (Coinbase Onramp or direct USDC). |
pay_withdraw |
Generate 1-hour withdrawal link. |
pay_mint |
Mint testnet USDC (Base Sepolia only). |
Discovery & Webhooks
| Tool | Description |
|---|---|
pay_discover |
Search paid API services by keyword/category. |
pay_webhook_register |
Register webhook for payment events (HMAC-signed). |
pay_webhook_list |
List registered webhooks. |
pay_webhook_delete |
Delete a webhook. |
Resources (5)
| URI | Description |
|---|---|
pay://wallet/status |
Balance, tabs, locked/available |
pay://wallet/tabs |
All open tabs |
pay://tab/{tab_id} |
Single tab detail |
pay://wallet/address |
Wallet address |
pay://network |
Network config + contract addresses |
Prompts (3)
| Prompt | Description |
|---|---|
pay-for-service |
Guided: discover service, evaluate pricing, make request |
review-tabs |
Review tabs, flag idle, suggest close/topup |
fund-wallet |
Generate fund link, explain deposit process |
Development
git clone https://github.com/pay-skill/pay-mcp.git
cd pay-mcp
npm install
npm run build
npm test # unit tests (mocked)
npm run test:acceptance # testnet (requires PAYSKILL_SIGNER_KEY)
License
MIT
