What is the UUID referenced in the API for scheduled_events?

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": [],
  "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!!

Instead of referencing unique resources by an ID, which can be common in some RESTful APIs, we've decided that a more uniform approach to identifying a resource is to use a Uniform Resource Identifier (URI).

{

  "resource": {

    "uri": "https://api.calendly.com/users/AAAAAAAAAAAAAAAA",

    "name": "John Doe",

    "slug": "acmesales",

    "email": "user@example.com",

    "scheduling_url": "https://calendly.com/acmesales",

    "timezone": "America/New York",

    "time_notation": "12h",

    "avatar_url": "https://01234567890.cloudfront.net/uploads/user/avatar/0123456/a1b2c3d4.png",

    "created_at": "2019-01-02T03:04:05.678123Z",

    "updated_at": "2019-08-07T06:05:04.321123Z",

    "current_organization": "https://api.calendly.com/organizations/AAAAAAAAAAAAAAAA",

    "resource_type": "User",

    "locale": "en"

  }

}

Quick fix on my last post, the entire URI is the UUID.