Connecting your AI agent

Once you’ve enabled tools and generated your subscription key in the admin portal, you have everything needed to connect agents. The following sections walk through configuration for popular AI platforms (Claude Desktop, Microsoft Copilot Studio) and custom integrations using the MCP SDK. The setup is straightforward: add your endpoint URL and subscription key to your agent’s configuration, and the agent can immediately start discovering and invoking banking tools.

Prerequisites

Before connecting, ensure you have:

MCP endpoint URL

Your unique Grand Central MCP server URL

Subscription key

API subscription key for authentication

JWT configuration

User authentication token details

AI agent

Claude Desktop, Microsoft Copilot, or custom MCP client

Configuration

Each AI platform has slightly different configuration patterns, but the core information is the same: endpoint URL, subscription key, and optional JWT token for user context. Choose the section below that matches your agent platform.

Claude desktop

Claude Desktop uses a JSON configuration file (typically ~/Library/Application Support/Claude/claude_desktop_config.json on macOS). Add Grand Central as an MCP server:

{
  "mcpServers": {
    "grandcentral": {
      "command": "mcp",
      "args": ["remote", "https://gc-prod-instance.example.com/mcp"],
      "env": {
        "SUBSCRIPTION_KEY": "a1b2c3d4e5f6g7h8i9j0"
      }
    }
  }
}

If you need user-scoped operations (e.g., fetching a specific customer’s transaction history), add the JWT token to the env object:

"env": {
  "SUBSCRIPTION_KEY": "a1b2c3d4e5f6g7h8i9j0",
  "JWT_TOKEN": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9..."
}

Restart Claude Desktop after editing the config file. Claude will automatically discover tools on next launch.

Microsoft Copilot Studio

Copilot Studio supports MCP servers through its plugin system. Add Grand Central as a plugin:

Open Copilot Studio and navigate to Plugins → Add Plugin
Select Model Context Protocol as the plugin type
Fill in the configuration form:
- Name: Grand Central Banking Tools
- URL: https://gc-prod-instance.example.com/mcp
- Auth Type: Bearer Token + Subscription Key
- Subscription Key: Your subscription key (e.g., a1b2c3d4e5f6g7h8i9j0)
- Bearer Token (optional): JWT token for user-scoped operations

The plugin will appear in your Copilot’s available tools list after saving. Copilot automatically discovers tools from the MCP server and makes them available during conversations.

Custom MCP client

If you’re building a custom agent or integrating Grand Central into an existing application, use the MCP SDK to connect programmatically. Here’s a TypeScript example:

import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";

const client = new Client({
  name: "jetbank-lending-agent",
  version: "1.0.0"
}, {
  capabilities: {
    tools: {}  // Declare that this client supports tool invocation
  }
});

await client.connect({
  command: "mcp",
  args: ["remote", "https://gc-prod-instance.example.com/mcp"],
  env: {
    "SUBSCRIPTION_KEY": process.env.GC_SUBSCRIPTION_KEY,
    "JWT_TOKEN": process.env.GC_JWT_TOKEN  // Optional, for user-scoped ops
  }
});

// Client is now connected and can list/invoke tools
const tools = await client.request({ method: "tools/list" });
console.log(`Discovered ${tools.tools.length} banking tools`);

The SDK handles JSON-RPC protocol details, connection management, and error handling automatically. You just need to provide credentials and endpoint configuration.

Authentication

Grand Central requires subscription key authentication for all requests, with optional JWT token authentication for user-scoped operations. The authentication model mirrors Azure API Management patterns - familiar if you’ve worked with Azure services. Subscription keys identify your agent or application and enforce rate limits tied to your subscription tier. Include the key in all requests using the Ocp-Apim-Subscription-Key header:

POST /mcp HTTP/1.1
Host: gc-prod-instance.example.com
Content-Type: application/json
Ocp-Apim-Subscription-Key: a1b2c3d4e5f6g7h8i9j0

{"jsonrpc": "2.0", "method": "tools/list", "id": 1}

JWT tokens provide user context for operations that need to know which customer the agent is acting on behalf of. For example, getTransactionHistory might require a JWT containing the customer ID claim. Add JWT tokens via the Authorization header:

POST /mcp HTTP/1.1
Host: gc-prod-instance.example.com
Content-Type: application/json
Ocp-Apim-Subscription-Key: a1b2c3d4e5f6g7h8i9j0
Authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9...

{"jsonrpc": "2.0", "method": "tools/call", "params": {...}, "id": 2}

Most tools work with subscription key only - you don’t need user context for operations like currency conversion or fetching exchange rates. Check tool schemas during discovery to see which operations require JWT tokens (look for x-mcp-requires-user-context: true in OpenAPI definitions).

Never commit credentials to version control. Store subscription keys and JWT tokens in environment variables (.env files excluded via .gitignore) or secure vaults (Azure Key Vault, AWS Secrets Manager, HashiCorp Vault). Rotate keys regularly and revoke compromised keys immediately via the Grand Central admin portal.

Testing your connection

Before integrating Grand Central into production workflows, verify that your credentials work and tools are accessible. Use curl or any HTTP client to test the connection - no special MCP client needed for these basic checks. List available tools to confirm your subscription has access:

curl -X POST https://gc-prod-instance.example.com/mcp \
  -H "Content-Type: application/json" \
  -H "Ocp-Apim-Subscription-Key: a1b2c3d4e5f6g7h8i9j0" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tools/list",
    "id": 1
  }'

You should see a JSON-RPC response with a result.tools array containing tool definitions:

{
  "jsonrpc": "2.0",
  "result": {
    "tools": [
      {
        "name": "getAccountBalance",
        "description": "Get current balance for a bank account",
        "inputSchema": {
          "type": "object",
          "properties": {
            "accountId": {"type": "string", "pattern": "^ACC-[0-9]{6}$"}
          },
          "required": ["accountId"]
        }
      },
      {
        "name": "getCustomerProfile",
        "description": "Retrieve customer information",
        "inputSchema": {...}
      }
    ]
  },
  "id": 1
}

If you see an empty tools array or a 401 error, check your subscription key in the admin portal. Invoke a tool to test the full request/response cycle:

curl -X POST https://gc-prod-instance.example.com/mcp \
  -H "Content-Type: application/json" \
  -H "Ocp-Apim-Subscription-Key: a1b2c3d4e5f6g7h8i9j0" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tools/call",
    "params": {
      "name": "getAccountBalance",
      "arguments": {"accountId": "ACC-789456"}
    },
    "id": 2
  }'

A successful response looks like:

{
  "jsonrpc": "2.0",
  "result": {
    "content": [
      {
        "type": "text",
        "text": "{\"accountId\":\"ACC-789456\",\"currentBalance\":15234.50,\"availableBalance\":14800.00,\"currency\":\"USD\"}"
      }
    ]
  },
  "id": 2
}

If you see errors, check the error.code and error.message fields. Common issues: -32602 (invalid parameters), -32001 (authentication failure), -32000 (backend API error).

Troubleshooting

401 unauthorized

Cause: Invalid or expired credentialsSolution:

Verify subscription key is correct
Check JWT token hasn’t expired
Ensure token audience matches Grand Central instance

429 rate limit exceeded

Cause: Too many requests in time windowSolution:

Implement exponential backoff
Check your rate limits in the admin portal
Adjust limits through the portal if needed

No tools returned

Cause: No tools enabled for your subscriptionSolution:

Log into the admin portal and enable tools from the API catalog
Verify your subscription key has access to the tools you enabled

Next steps

Tool discovery

Learn how tool discovery works

Authentication

Understand authentication in detail

Rate limiting

Learn about rate limits and quotas

Best practices

Follow patterns for reliable integrations

Overview

Architecture and technology

Agent Development Lifecycle

Get started

Starter kits

BB AI SDK

MCP support

CI/CD workflows

Prerequisites

MCP endpoint URL

Subscription key

JWT configuration

AI agent

Configuration

Claude desktop

Microsoft Copilot Studio

Custom MCP client

Authentication

Testing your connection

Troubleshooting

Next steps

Tool discovery

Authentication

Rate limiting

Best practices

​Prerequisites

MCP endpoint URL

Subscription key

JWT configuration

AI agent

​Configuration

​Claude desktop

​Microsoft Copilot Studio

​Custom MCP client

​Authentication

​Testing your connection

​Troubleshooting

​Next steps

Tool discovery

Authentication

Rate limiting

Best practices

Prerequisites

Configuration

Claude desktop

Microsoft Copilot Studio

Custom MCP client

Authentication

Testing your connection

Troubleshooting

Next steps