Recipes / Book meetings from replies

Book meetings from replies

Instantly + Calendly + HubSpot

Who it's for

Outbound teams who want interested replies turned into booked meetings and logged in the CRM, with a human checking each one.

MCP servers

• Instantly Up · auth
  https://mcp.instantly.ai/mcp
  API key (Authorization header or URL path)
• Calendly Up · auth
  https://mcp.calendly.com
  OAuth 2.1 + PKCE with Dynamic Client Registration
• HubSpot Up · auth
  https://mcp.hubspot.com
  OAuth 2.1 with PKCE (MCP connector)

Auth setup

• Instantly: Paste an API key from the vendor's settings into the config (header or URL). There's no browser login, so it works well headless.
• Calendly: Sign in with OAuth in your client (run /mcp in Claude Code). Do it once interactively, and the client stores and refreshes the token.
• HubSpot: Sign in with OAuth in your client (run /mcp in Claude Code). Do it once interactively, and the client stores and refreshes the token.

mcp.json config for Claude Code and Cursor

Put this in .mcp.json (Claude Code, project root) or ~/.cursor/mcp.json (Cursor). Swap the example keys for your own, and don't commit real ones. Remove the // comment lines if your client requires strict JSON.

{
  "mcpServers": {
    "instantly": {
      "url": "https://mcp.instantly.ai/mcp",
      "headers": { "Authorization": "YOUR_INSTANTLY_API_KEY" }
    },
    "calendly": {
      "url": "https://mcp.calendly.com"
    },
    "hubspot": {
      "url": "https://mcp.hubspot.com"
    }
  }
}

Step-by-step prompts

1. Show my unread Instantly replies from the last 24 hours and classify each one: interested, not now, unsubscribe, or other.
2. For each interested reply, check my Calendly availability for the next 5 business days and create a single-use scheduling link for my intro event type.
3. Draft a short reply to each interested lead with the link. Show me all drafts. Send only the ones I approve.
4. For each one I approve, create or update the contact in HubSpot, set the lifecycle stage to lead, and log the reply as an activity.

Gotchas

• Calendly is OAuth 2.1 with PKCE and Dynamic Client Registration. Clients without DCR support need a different setup.
• Sending replies from Instantly is a real email. Keep a human approval step on every send.
• Instantly also has its own built-in reply agent that can share Calendly links. Use that instead if you don't need Claude in the loop.
• Watch for unsubscribe replies, and never send those leads a link.

Vendor sites: Instantly · Calendly · HubSpot. If we join an affiliate program, these links will be labeled as affiliate links.