If I go here:

https://developer.calendly.com/api-docs/2d5ed9bbd2952-list-events

The page never mentions a UUID. I cannot find a reference to the UUID anywhere in any of the descriptive text, and yet it is listed as a required parameter when asking for the invitees.

Hi there,

Thanks for your detailed post—happy to help clarify the steps for retrieving event and invitee data using the Calendly API.

Step 1: List Scheduled Events (not Event Types)

It looks like you're currently calling the /event_types endpoint, which returns event templates—not actual scheduled bookings. To retrieve the actual events that occurred (including those with external invitees), you’ll want to use:

GET https://api.calendly.com/scheduled_events

Include query parameters like organization= or user= along with a min_start_time and max_start_time to filter by date range. Example:

curl --request GET \
  --url "https://api.calendly.com/scheduled_events?organization=https://api.calendly.com/organizations/{org_uuid}&min_start_time=2025-01-01T00:00:00Z&max_start_time=2025-06-30T23:59:59Z" \
  --header 'Authorization: Bearer {your_token}' \
  --header 'Content-Type: application/json'

This will return a list of scheduled event objects, each with a unique uri and uuid.

Step 2: List Invitees for a Scheduled Event

Once you have the UUIDs from /scheduled_events, you can fetch the list of invitees per event using:

GET /scheduled_events/{uuid}/invitees

Important: Remove the organization= query param—this endpoint doesn’t require it. Example:

curl --request GET \
  --url "https://api.calendly.com/scheduled_events/{event_uuid}/invitees" \
  --header 'Authorization: Bearer {your_token}' \
  --header 'Content-Type: application/json'

If you’re getting a Resource not found error, double-check that:

• The uuid you’re using came from /scheduled_events, not /event_types

• Your token has access to the organization or user tied to the event

Tip: Use Pagination

Both endpoints use pagination, so make sure to follow the next_page URL in the response to retrieve all records.

If you’d like help reviewing your API token permissions or need a walkthrough, feel free to chat with our Support team at calendly.com/contact—we’re happy to assist further.

Hope this clears things up!
– Javay
Developer Support, Calendly

But if I use the external_id field then I get: 

{"title":"Resource Not Found","message":"The server could not find the requested resource."}

making this call, with the external_id from above:

curl --request GET \
  --url "https://api.calendly.com/scheduled_events/8pv58mskifkj5st9o6m2qqde74/invitees?organization=https://api.calendly.com/organizations/DCFERasdasdasdasd7OLC" \
  --header 'Authorization: Bearer eyJraWQiOiIxY2UxZTEzNjE3ZGNmNzY2YjNjZWJjY2Y4ZGM1YmFmYThhNjVlNjg0MDIzZjdjMzJiZTgzNDliMjM4MDEzNWI0IiwidHlasdasdasdasdasQxLTRlMzUtYmQxMy03ZTBhNWIwNDk2MjciLCJ1c2VyX3V1aWQiOiJBSEhCasdasdasdElEQVJMWkU3In0.jsvcK0mRkCdIF87BJ7UxVaHfQDWClDc-QEIl-PyYuXYVm95wDIWR4r-_Xw7IwLp_18Q-amd8BGmsa5deb0P9qw' \
  --header 'Content-Type: application/json'
 

I also removed the “organization” parameter, but I still get “resource not found”.

My other post never showed up? I posted the JSON so that you could see what I was getting. It did not have a field called “uuid”. It did have a field called “external_id” but that does not seem to work. 

Again, this is the JSON that comes back. It does not have a field called “uuid”.

{
  "calendar_event": {
    "external_id": "",
    "kind": "google"
  },
  "created_at": "2024-12-13T13:26:31.739208Z",
  "end_time": "2025-01-06T17:30:00.000000Z",
  "event_guests": v],
  "event_memberships": _
    {
      "buffered_end_time": "2025-01-06T18:00:00.000000Z",
      "buffered_start_time": "2025-01-06T17:00:00.000000Z",
      "user": "https://api.calendly.com/users/HHF",
      "user_email": "",
      "user_name": "B R"
    }
  ],
  "event_type": "https://api.calendly.com/event_types/
  "invitees_counter": {
    "active": 9,
    "limit": 15,
    "total": 10
  },
  "location": {
    "data": {
      "id": 86518512501,
      "settings": {
        "global_dial_in_numbers": "
          {
            "country_name": "US",
            "city": "Chicago",
            "number": "+9",
            "type": "toll",
            "country": "US"
          },
          {
            "country_name": "US",
            "number": "+1 11
            "type": "toll",
            "country": "US"
          },
          {
            "country_name": "US",
            "city": "New York",
            "number": "+1 9",
            "type": "toll",
            "country": "US"
          }
        ]
      },
      "extra": {
        "intl_numbers_url": "https://us02web.zoom.us/u/kdswgJAiDz"
      },
      "password": "31824"
    },
    "join_url": "https://us0.zoom.us/j/8c6Cpr.1",
    "status": "pushed",
    "type": "zoom"
  },
  "meeting_notes_html": null,
  "meeting_notes_plain": null,
  "name": "Platform Tour",
  "start_time": "2025-01-06T17:00:00.000000Z",
  "status": "active",
  "updated_at": "2025-01-04T02:00:37.235430Z",
  "uri": "https://api.calendly.com/scheduled_events/d662"
}

Any thoughts about why I am not seeing a UUID? I’ve tried every ID in the return that looks like ID and yet I’m still yet every API call returns with “Resource Not Found.”

Can anyone help me with this? I am making an API call. There is no field called UUID in the values returned. What should I use as a substitute for the UUID?

Can anyone answer this? There is no field called “UUID”. I posted the JSON above. What are people using instead? What field do people use for the UUID? 

Can anyone make a suggestion here? Does anyone work with this API?

Does anyone answer these questions? Is there another source of support? Should I report this as a bug? Why is the UUID missing?

Does anyone know anything about the field called UUID?

You're querying the /event_types endpoint, which returns event templates, not scheduled events. To get all events that actually occurred in the last 6 months, you’ll want to use the /scheduled_events endpoint instead, and apply a min_start_time and max_start_time filter in your query.

Once you have the event UUIDs from there, you can call /scheduled_events/{uuid}/invitees to get the list of attendees for each

Thanks for the info!!