Claude + Cursor MCP Setup Guide: API Key, Headers, mcp-remote, and Troubleshooting

This guide shows the fastest path to a working Claude MCP setup and Cursor MCP setup with Vantaj.

You will connect to:

https://api.vantaj.co/mcp

You will authenticate with:

Authorization: Bearer vtj_live_your_key

For a strategic overview, read MCP Monitoring Server: Connect Claude and Cursor to Real Uptime Data.

Prerequisites

Before setup, confirm three things:

1. You have a paid Vantaj plan with API access
2. You created an API key under Settings -> API Keys
3. Your key has the scopes you need

If you have not generated a key yet, follow API keys.

1) Claude (Web or Desktop) MCP Setup

In Claude settings, add a custom connector.

• URL: https://api.vantaj.co/mcp
• Header: Authorization: Bearer vtj_live_your_key

After saving, ask Claude:

• "List my projects"
• "List monitors for project <project_id>"

If those calls work, auth and transport are configured.

2) Claude Code MCP Setup

Use the CLI command:

claude mcp add --transport http vantaj https://api.vantaj.co/mcp \
  --header "Authorization: Bearer vtj_live_your_key"

Then test with a direct prompt in Claude Code:

• "Use Vantaj MCP to list projects"

3) Cursor MCP Setup (.cursor/mcp.json)

Create or update .cursor/mcp.json:

{
  "mcpServers": {
    "vantaj": {
      "url": "https://api.vantaj.co/mcp",
      "headers": { "Authorization": "Bearer vtj_live_your_key" }
    }
  }
}

Restart Cursor after editing config.

Then test with:

• "Use the vantaj MCP server and list projects"

4) Local-Only MCP Clients: Use mcp-remote

Some clients only support stdio servers.

Use mcp-remote as a bridge:

{
  "mcpServers": {
    "vantaj": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://api.vantaj.co/mcp",
        "--header",
        "Authorization: Bearer vtj_live_your_key"
      ]
    }
  }
}

This keeps the remote hosted endpoint while satisfying local transport requirements.

5) First Calls to Validate End-to-End Setup

Run these in order:

1. list_projects
2. list_monitors with a valid project_id
3. list_incidents with the same project_id

Why this order matters: most monitoring tools need a project_id, so discovery comes first.

For a full tool list, see MCP server docs.

Common MCP Setup Errors and Fixes

Error: unauthorized or auth failed

Cause:

• Missing Bearer prefix
• Expired or revoked key
• Typo in key value

Fix:

• Use exact header format from API keys
• Generate a new key if needed
• Use a dedicated key per client so rotation is easy

Error: no tools available

Cause:

• Client saved config in the wrong location
• App did not reload config

Fix:

• Confirm path and JSON syntax
• Restart the client
• Re-run a simple discovery prompt: "list projects"

Error: permission denied for write actions

Cause:

• Key has read-only scopes

Fix:

• Keep read-only for analysis workflows
• Create a second key for controlled write workflows

Error: expected delete tool is missing

Cause:

• The MCP surface excludes destructive operations by design

Fix:

• Use dashboard or REST API for destructive actions
• Keep MCP for reads and additive writes

For the full guardrail rationale, read How to Secure an MCP Server for AI Agents: Scopes, Limits, and Safe Tool Design.

Setup Patterns That Scale Across Teams

Use these defaults if you are rolling MCP across a team:

• One key per environment (dev, staging, prod)
• One key per client type (Claude, Cursor, automation)
• Read-only by default
• Narrow write keys for monitor creation workflows
• Quarterly key rotation

These patterns keep blast radius small and access auditable.

Strong Internal Linking for This Topic Cluster

If this post sits in your docs hub, link it to:

• Product page: MCP Server
• Documentation: MCP server docs
• Auth model: API keys
• Strategy article: MCP Monitoring Server
• Security article: MCP server security
• Adjacent reliability article: How to Monitor an LLM API

Final Checklist

If all boxes are true, your setup is production-ready:

• Endpoint set to https://api.vantaj.co/mcp
• Header format is valid bearer auth
• list_projects succeeds
• Scopes match intended actions
• Team keys are segmented by use case