Turn the Stripe API into MCP tools for Claude

Stripe is the API most teams want their AI to read first — customers, invoices, balances, and subscriptions all in one place. In this recipe you'll expose Stripe's REST API as a secure, read-only MCP server so you can ask "what's our balance?" or "show this customer's invoices" straight from Claude. We keep it read-only by default, because money operations deserve human hands.

1. Create a restricted Stripe API key

In the Stripe Dashboard, go to Developers → API keys → Create restricted key. Grant readpermissions only on the resources you want (Customers, Invoices, Balance), and leave everything else at "None." Copy the key — it starts with rk_live_ (or rk_test_ for test mode).

2. Create a workspace and point it at Stripe's spec

Create a new workspace in Cast, open the Upload tab, and provide Stripe's OpenAPI specification. Stripe publishes one publicly, so you can paste its URL or upload the file. Wait for tool generation to finish.

3. Configure auth — Bearer Token

Stripe authenticates with the secret key as a bearer token (Authorization: Bearer rk_live_…). Switch to the Configure tab, choose Bearer Token, set the API base URL to https://api.stripe.com, and paste your restricted key.

4. Enable read tools, disable the rest

Stripe's spec is large. Enable just the read operations you need and leave anything that changes state switched off:

5. Get your MCP URL

Open the Connect tab and copy the snippet for your client. Your AI client connects to the URL; Cast adds the Stripe key on every upstream request.

{
  "mcpServers": {
    "stripe": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote@latest",
        "https://mcp.getcast.io/stripe-cmpstrp9001"
      ]
    }
  }
}

Try it

"List our 5 most recent Stripe customers and their email addresses."
"What is our current available balance?"
"Show unpaid invoices for customer cus_123."

6. Watch sessions, then add the next tools

Launching read-only isn't the finish line — it's the start of a feedback loop. Cast tracks every client connection as a session, with its geography, duration, and tool-call count, so you can see who's actually using your Stripe server:

More valuable still, Cast analyzes the order of calls across sessions and surfaces recurring patterns — including the moments where agents reach for something you haven't enabled. That's your signal for which tool to add next:

Here the data shows users repeatedly trying to check a subscription right after looking up a customer — but getSubscription was never enabled. Rather than guess, you go back to the Configure tab, toggle it on, save, and the next session has the tool it was looking for. You expand the server based on real demand, not assumptions.

Production checklist

• Use a restricted, read-only key — never your full secret key.
• Keep refunds, charges, and deletes disabled.
• Start in test mode (rk_test_) to validate before going live.
• Review the Logs and Patterns tabs to confirm what's read and what to add next.

Frequently asked questions