Connect Cursor to pr402

Audience: You use Cursor (or another MCP host) and want pr402 buyer/seller tools without writing HTTP glue.

Package: @pr402/mcp-server@0.1.2 — stdio MCP adapter over @pr402/client.

Version pin: Use @pr402/mcp-server@0.1.2. Versions 0.1.0 and 0.1.1 are broken — do not use them.

Install

npx -y @pr402/mcp-server@0.1.2

Configure Cursor

Create or edit .cursor/mcp.json in your project (or user-level MCP settings):

{
  "mcpServers": {
    "pr402": {
      "command": "npx",
      "args": ["-y", "@pr402/mcp-server@0.1.2"],
      "env": {
        "PR402_FACILITATOR_URL": "https://preview.ipay.sh",
        "PR402_PAYER_KEYPAIR_JSON": "/absolute/path/to/buyer-keypair.json"
      }
    }
  }
}

Restart Cursor after saving. PR402_PAYER_KEYPAIR_JSON is required only for pr402_pay_http_resource (auto-pay). Other tools work without it.

Copy-paste example: x402-buyer-starter examples/mcp/cursor-mcp.json.

Devnet vs Mainnet

Set PR402_FACILITATOR_URL to the facilitator origin that matches your keypair and the seller you pay:

Environment	PR402_FACILITATOR_URL
Preview (Devnet)	https://preview.ipay.sh
Production (Mainnet)	https://ipay.sh

Same service is also served at https://preview.agent.pay402.me (Devnet) and https://agent.pay402.me (Mainnet). Confirm solanaNetwork with GET /api/v1/facilitator/health on the host you use.

Use a funded Devnet keypair with preview; Mainnet keypair and real funds with ipay.sh.

Tools

Tool	Role
pr402_get_capabilities	Buyer — facilitator features and solanaNetwork
pr402_build_exact_payment	Buyer — unsigned exact payment tx + verifyBodyTemplate
pr402_pay_http_resource	Buyer — auto-pay an HTTP resource (needs payer keypair)
pr402_seller_preview	Seller — lifecycle and rail preview
pr402_seller_rail_info	Seller — payTo PDA for a scheme
pr402_seller_provision_tx	Seller — unsigned Activate tx
pr402_enrich_payment_required	Seller — enrich naive 402 → institutional shape

Machine-readable catalog: GET /agent-tools.json on your facilitator host — e.g. preview.ipay.sh/agent-tools.json.

Further reading

• Agent integration runbook — full buyer/seller narrative; live copy at /agent-integration.md
• @pr402/mcp-server on npm
• Buyer Quickstart — protocol steps under the MCP tools

Try it (Devnet)

After configuring a funded Devnet keypair, ask Cursor to call pr402_get_capabilities or pr402_pay_http_resource against a preview seller URL.