AI stops answering in Voice Chat and when I use Text Chat it starts an error called Failed to get LLM response Error: Error encountered in LLM call

Support Help
2

The “error validating cal.com tools” message when using the book_appointment_cal function typically stems from credential issues(1).

Required Configuration

The book_appointment_cal tool requires these specific fields(2)(3)(4)(5):

{
  "type": "book_appointment_cal",
  "name": "book_appointment",
  "description": "Book an annual check up.",
  "cal_api_key": "cal_live_xxxxxxxxxxxx",
  "event_type_id": 60444,
  "timezone": "America/Los_Angeles"
}

(2), (3), (4), (5)

Common Issues to Check

  1. Event Type ID Format - Must be a number only (e.g., 60444), not a URL or string with slashes(1)

  2. API Key Format - Should start with cal_live_ for production keys(2)(3)(4)(5)

  3. API Key Validity - Try regenerating your API key in Cal.com settings(1)

  4. API Key Permissions - Verify the key has proper permissions in Cal.com(1)

How to Get Credentials

  • Navigate to Settings → Developer → API Keys in your Cal.com dashboard(1)
  • The Event Type ID is the number in the URL when you open your event type (e.g., in https://app.cal.com/your-username/event-type/1427703, the ID is 1427703)(1)

Troubleshooting Steps

  • Create a new API key in Cal.com(1)
  • Test the API key directly with Cal.com’s API outside of Retell to confirm it works(1)
  • Double-check that the Event Type ID matches exactly what’s in your Cal.com URL(1)
  • Ensure you’re copying the complete API key without extra spaces(1)

The timezone parameter is optional but recommended(1).