Connect Claude or Cursor to free MCP previews

Connect the free preview server

Use this remote MCP URL (Streamable HTTP):

https://draconic21-x402-api.onrender.com/mcp/free

Claude and Claude Desktop

1. Open Customize → Connectors, choose + Add → Add custom connector, and name it draconic21 free previews.
2. Enter the URL above. Choose No sign in when reviewing authentication; this endpoint needs no request headers or credentials.
3. Finish adding it, then enable it for your conversation from + → Connectors.

On Team or Enterprise, an organization owner must first add the connector. See Claude’s current custom-connector instructions for plan and role details. Remote connectors use this account setting; the local Desktop JSON configuration is a separate mechanism.

Cursor

Add this entry to .cursor/mcp.json in your project, or ~/.cursor/mcp.json for all projects. Merge it with any servers you already have:

{
  "mcpServers": {
    "draconic21-free": {
      "url": "https://draconic21-x402-api.onrender.com/mcp/free"
    }
  }
}

Save and restart Cursor, then enable the tools you want. See Cursor’s MCP setup instructions.

Try one free preview

Ask your assistant:

Preview tools describe example requests and responses so you can inspect the format. They do not fetch a fresh company report. The free connection contains catalog and preview tools only; it cannot submit a payment or spend a prepaid credit.

Optional: move from a preview to paid data

For paid calls, connect an x402-capable client to https://draconic21-x402-api.onrender.com/mcp. Adding a connector to Claude or Cursor does not give it a payment wallet. Your own client must handle the signed payment; start with the payment guide.

x402 is HTTP-native (a 402 status + a signed header) and MCP tool calls don't carry raw HTTP headers, so this server bridges the two the same way community x402-over-MCP servers do (see MetaMask's mcp-x402 and the x402 docs' MCP guide):

1. Call a paid tool, e.g. sanctions_screen, with just your business arguments ({ "name": "..." }). No payment_header yet.
2. The result comes back with payment_required: true and the full payment challenge (price, network eip155:8453, asset, payTo).
3. Your x402-capable client (any v2 client: @x402/core + @x402/evm, MetaMask's mcp-x402, or the Python x402 SDK) signs against that challenge.
4. Call the same tool again with the same arguments, adding payment_header: { "name": "PAYMENT-SIGNATURE", "value": "<signed payload>" }. The server attaches it verbatim and returns the paid result.

Previewable data tools have a free <name>_preview twin (no wallet, no payment, sample response) and there's a free list_catalog tool listing every price. See the public agent catalog for routes and prices, and call the free list_catalog MCP tool for the current tool list.

For paid calls only

• A wallet on the Base network (chain id 8453) with enough USDC for the price returned in the payment challenge.
• An x402 v2 client library (see the payment guide above) that can sign the "exact" EVM payment scheme (EIP-3009, gasless — no ETH for gas needed on your side).
• Your wallet's private key available to your own process/agent — never share it, never commit it, never paste it into a chat with an AI you don't fully trust with funds.

More

Selling your own API to agents instead of buying? Our Paid MCP Server Kit ($19+ one-time, pay what you want) packages the same free-preview + x402-paid MCP pattern as a tested template you can customize. Want both the HTTP and MCP kits? The x402 Builder Bundle is $35+.