diff --git a/src/components/card/CardSidebar.vue b/src/components/card/CardSidebar.vue
index b1c285651..2060c0c0a 100644
--- a/src/components/card/CardSidebar.vue
+++ b/src/components/card/CardSidebar.vue
@@ -33,10 +33,17 @@
 			<ActionButton v-if="cardDetailsInModal" icon="icon-menu-sidebar" @click.stop="showModal()">
 				{{ t('deck', 'Open in sidebar view') }}
 			</ActionButton>
-
 			<ActionButton v-else icon="icon-external" @click.stop="showModal()">
 				{{ t('deck', 'Open in bigger view') }}
 			</ActionButton>
+
+			<ActionButton v-for="action in cardActions"
+				:key="action.label"
+				:close-after-click="true"
+				:icon="action.icon"
+				@click="action.callback(cardRichObject)">
+				{{ action.label }}
+			</ActionButton>
 		</template>
 
 		<AppSidebarTab id="details"
@@ -73,6 +80,7 @@
 
 <script>
 import { ActionButton, AppSidebar, AppSidebarTab } from '@nextcloud/vue'
+import { generateUrl } from '@nextcloud/router'
 import { mapState, mapGetters } from 'vuex'
 import CardSidebarTabDetails from './CardSidebarTabDetails'
 import CardSidebarTabAttachments from './CardSidebarTabAttachments'
@@ -114,7 +122,7 @@ export default {
 			currentBoard: state => state.currentBoard,
 			cardDetailsInModal: state => state.cardDetailsInModal,
 		}),
-		...mapGetters(['canEdit', 'assignables']),
+		...mapGetters(['canEdit', 'assignables', 'cardActions', 'stackById']),
 		title() {
 			return this.titleEditable ? this.titleEditing : this.currentCard.title
 		},
@@ -124,6 +132,15 @@ export default {
 		subtitle() {
 			return t('deck', 'Modified') + ': ' + this.relativeDate(this.currentCard.lastModified * 1000) + ' ' + t('deck', 'Created') + ': ' + this.relativeDate(this.currentCard.createdAt * 1000)
 		},
+		cardRichObject() {
+			return {
+				id: '' + this.currentCard.id,
+				name: this.currentCard.title,
+				boardname: this.currentBoard.title,
+				stackname: this.stackById(this.currentCard.stackId)?.title,
+				link: window.location.protocol + '//' + window.location.host + generateUrl('/apps/deck/') + `#/board/${this.currentBoard.id}/card/${this.currentCard.id}`,
+			}
+		},
 	},
 	methods: {
 		handleUpdateTitleEditable(value) {
diff --git a/src/main.js b/src/main.js
index 710e31c59..3ac1249dd 100644
--- a/src/main.js
+++ b/src/main.js
@@ -103,3 +103,40 @@ new Vue({
 	},
 	render: h => h(App),
 })
+
+if (!window.OCA.Deck) {
+	window.OCA.Deck = {}
+}
+
+/**
+ * @typedef {Object} CardRichObject
+ * @property {string} id
+ * @property {string} name
+ * @property {string} boardname
+ * @property {string} stackname
+ * @property {string} link
+ */
+
+/**
+ * @callback registerActionCallback
+ * @param {CardRichObject} card
+ */
+
+/**
+ * Frontend message API for adding actions to talk messages.
+ * @param {*} Object the wrapping object.
+ * @param {String} label the action label.
+ * @param {registerActionCallback} callback the callback function. This function will receive
+ * the card as a parameter and be triggered by a click on the
+ * action. The card parameter will be of the format of a rich object string
+ * type "deck-card"
+ * @param {String} icon the action label. E.g. "icon-reply"
+ */
+window.OCA.Deck.registerCardAction = ({ label, callback, icon }) => {
+	const cardAction = {
+		label,
+		callback,
+		icon,
+	}
+	store.dispatch('addCardAction', cardAction)
+}
diff --git a/src/store/actions.js b/src/store/actions.js
new file mode 100644
index 000000000..722d778ca
--- /dev/null
+++ b/src/store/actions.js
@@ -0,0 +1,42 @@
+/*
+ * @copyright Copyright (c) 2021 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+export default {
+	state: {
+		actions: {
+			card: [],
+		},
+	},
+	getters: {
+		cardActions: (state) => state.actions.card,
+	},
+	mutations: {
+		ADD_CARD_ACTION(state, action) {
+			state.actions.card.push(action)
+		},
+	},
+	actions: {
+		async addCardAction({ commit }, action) {
+			commit('ADD_CARD_ACTION', action)
+		},
+	},
+}
diff --git a/src/store/main.js b/src/store/main.js
index 4987421b2..b36dc942c 100644
--- a/src/store/main.js
+++ b/src/store/main.js
@@ -28,6 +28,7 @@ import Vuex from 'vuex'
 import axios from '@nextcloud/axios'
 import { generateOcsUrl } from '@nextcloud/router'
 import { BoardApi } from '../services/BoardApi'
+import actions from './actions'
 import stack from './stack'
 import card from './card'
 import comment from './comment'
@@ -47,6 +48,7 @@ export const BOARD_FILTERS = {
 
 export default new Vuex.Store({
 	modules: {
+		actions,
 		stack,
 		card,
 		comment,
diff --git a/src/store/stack.js b/src/store/stack.js
index 3f428e71f..bbb0486be 100644
--- a/src/store/stack.js
+++ b/src/store/stack.js
@@ -34,6 +34,9 @@ export default {
 		stacksByBoard: state => (id) => {
 			return state.stacks.filter((stack) => stack.boardId === id).sort((a, b) => a.order - b.order)
 		},
+		stackById: state => (id) => {
+			return state.stacks.find((stack) => stack.id === id)
+		},
 	},
 	mutations: {
 		addStack(state, stack) {