---
title: "Cancel an Outlook meeting and notify attendees"
method: POST
path: "/v1/capabilities/microsoft-365/calendar-events/{eventId}/cancel"
tags: ["Capability Sources"]
---

# Cancel an Outlook meeting and notify attendees

`POST /v1/capabilities/microsoft-365/calendar-events/{eventId}/cancel`

## Request

- Base URL: `https://api.openworklabs.com`
- URL: `https://api.openworklabs.com/v1/capabilities/microsoft-365/calendar-events/{eventId}/cancel`
- Auth: one of:
  - API key in header `x-api-key`
  - HTTP bearer

Requires Calendars.ReadWrite and calendarWrite. Only the meeting organizer can cancel via Graph. Requires explicit user cancellation confirmation; a 202 receipt means cancellation was accepted. Uses only the calling member's delegated Microsoft 365 connection. Never automatically retry a mutation after a timeout, cancellation, or ambiguous response; inspect current state first.

## Path parameters

- `eventId` string, required

## Request body

- Microsoft365CalendarCancelBody
  - `confirmCancel` true, required: The user explicitly requested cancellation, including attendee notifications.
  - `comment` string

## Response `200`

Microsoft Graph mutation receipt returned.

- Microsoft365CalendarCancelResponse
  - `ok` true, required
  - `eventId` string, required
  - `status` 'accepted', required

## Other responses

- `401`: The caller must be signed in.
- `409`: The selected feature or delegated permission is missing.
- `413`: Request body exceeds 1 MiB.
- `502`: Microsoft Graph rejected the request or the outcome is unknown.

## Changes

- **2026-09-11** `bb8ff73e4ad3`: 2 info
  - the endpoint scheme security `bearerAuth` was added to the API
  - the endpoint scheme security `denApiKey` was added to the API
- **2026-09-10** `7d79c843d137`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/openworklabs/apis/den-api/changes/v1/capabilities/microsoft-365/calendar-events/:eventId/cancel/post.md)

---

[API](https://skmtc.dev/openworklabs/apis/den-api.md) - [All operations](https://skmtc.dev/openworklabs/apis/den-api/llms.txt) - [OpenAPI document](https://skmtc.dev/openworklabs/apis/den-api/revisions/dafa2aa6044f?raw)