diff --git a/ghost/core/core/server/api/endpoints/posts.js b/ghost/core/core/server/api/endpoints/posts.js
index bb727f08a3..c019c38b3f 100644
--- a/ghost/core/core/server/api/endpoints/posts.js
+++ b/ghost/core/core/server/api/endpoints/posts.js
@@ -1,3 +1,4 @@
+const urlUtils = require('../../../shared/url-utils');
 const models = require('../../models');
 const getPostServiceInstance = require('../../services/posts/posts-service');
 const allowedIncludes = [
@@ -21,6 +22,22 @@ const unsafeAttrs = ['status', 'authors', 'visibility'];
 
 const postsService = getPostServiceInstance();
 
+/**
+ * @param {string} event
+ */
+function getCacheHeaderFromEventString(event, dto) {
+    if (event === 'published_updated' || event === 'unpublished') {
+        return true;
+    }
+    if (event === 'scheduled_updated' || event === 'draft_updated') {
+        return {
+            value: urlUtils.urlFor({
+                relativeUrl: urlUtils.urlJoin('/p', dto.uuid, '/')
+            })
+        };
+    }
+}
+
 module.exports = {
     docName: 'posts',
     browse: {
@@ -162,6 +179,7 @@ module.exports = {
 
     edit: {
         headers: {
+            /** @type {boolean | {value: string}} */
             cacheInvalidate: false
         },
         options: [
@@ -194,9 +212,11 @@ module.exports = {
             unsafeAttrs: unsafeAttrs
         },
         async query(frame) {
-            let model = await postsService.editPost(frame);
-
-            this.headers.cacheInvalidate = postsService.handleCacheInvalidation(model);
+            let model = await postsService.editPost(frame, {
+                eventHandler: (event, dto) => {
+                    this.headers.cacheInvalidate = getCacheHeaderFromEventString(event, dto);
+                }
+            });
 
             return model;
         }
diff --git a/ghost/core/test/e2e-api/admin/__snapshots__/posts.test.js.snap b/ghost/core/test/e2e-api/admin/__snapshots__/posts.test.js.snap
index 371d9c3533..095d70b1d9 100644
--- a/ghost/core/test/e2e-api/admin/__snapshots__/posts.test.js.snap
+++ b/ghost/core/test/e2e-api/admin/__snapshots__/posts.test.js.snap
@@ -974,6 +974,363 @@ Object {
 }
 `;
 
+exports[`Posts API Update Can add and remove collections 1: [body] 1`] = `
+Object {
+  "posts": Array [
+    Object {
+      "authors": Any<Array>,
+      "canonical_url": null,
+      "codeinjection_foot": null,
+      "codeinjection_head": null,
+      "comment_id": Any<String>,
+      "count": Object {
+        "clicks": 0,
+        "negative_feedback": 0,
+        "positive_feedback": 0,
+      },
+      "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+      "custom_excerpt": null,
+      "custom_template": null,
+      "email": null,
+      "email_only": false,
+      "email_segment": "all",
+      "email_subject": null,
+      "excerpt": null,
+      "feature_image": null,
+      "feature_image_alt": null,
+      "feature_image_caption": null,
+      "featured": false,
+      "frontmatter": null,
+      "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+      "meta_description": null,
+      "meta_title": null,
+      "mobiledoc": "{\\"version\\":\\"0.3.1\\",\\"ghostVersion\\":\\"4.0\\",\\"markups\\":[],\\"atoms\\":[],\\"cards\\":[],\\"sections\\":[[1,\\"p\\",[[0,[],0,\\"\\"]]]]}",
+      "newsletter": null,
+      "og_description": null,
+      "og_image": null,
+      "og_title": null,
+      "post_revisions": Any<Array>,
+      "primary_author": Any<Object>,
+      "primary_tag": Any<Object>,
+      "published_at": null,
+      "slug": "collection-update-test",
+      "status": "draft",
+      "tags": Any<Array>,
+      "tiers": Array [
+        Object {
+          "active": true,
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "currency": null,
+          "description": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "monthly_price": null,
+          "monthly_price_id": null,
+          "name": "Free",
+          "slug": "free",
+          "trial_days": 0,
+          "type": "free",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "visibility": "public",
+          "welcome_page_url": null,
+          "yearly_price": null,
+          "yearly_price_id": null,
+        },
+        Object {
+          "active": true,
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "currency": "usd",
+          "description": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "monthly_price": 500,
+          "monthly_price_id": null,
+          "name": "Default Product",
+          "slug": "default-product",
+          "trial_days": 0,
+          "type": "paid",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "visibility": "public",
+          "welcome_page_url": null,
+          "yearly_price": 5000,
+          "yearly_price_id": null,
+        },
+      ],
+      "title": "Collection update test",
+      "twitter_description": null,
+      "twitter_image": null,
+      "twitter_title": null,
+      "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+      "url": Any<String>,
+      "uuid": StringMatching /\\[a-f0-9\\]\\{8\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{12\\}/,
+      "visibility": "public",
+    },
+  ],
+}
+`;
+
+exports[`Posts API Update Can add and remove collections 2: [headers] 1`] = `
+Object {
+  "access-control-allow-origin": "http://127.0.0.1:2369",
+  "cache-control": "no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0",
+  "content-length": "3701",
+  "content-type": "application/json; charset=utf-8",
+  "content-version": StringMatching /v\\\\d\\+\\\\\\.\\\\d\\+/,
+  "etag": StringMatching /\\(\\?:W\\\\/\\)\\?"\\(\\?:\\[ !#-\\\\x7E\\\\x80-\\\\xFF\\]\\*\\|\\\\r\\\\n\\[\\\\t \\]\\|\\\\\\\\\\.\\)\\*"/,
+  "location": StringMatching /https\\?:\\\\/\\\\/\\.\\*\\?\\\\/posts\\\\/\\[a-f0-9\\]\\{24\\}\\\\//,
+  "vary": "Accept-Version, Origin, Accept-Encoding",
+  "x-powered-by": "Express",
+}
+`;
+
+exports[`Posts API Update Can add and remove collections 3: [body] 1`] = `
+Object {
+  "posts": Array [
+    Object {
+      "authors": Any<Array>,
+      "canonical_url": null,
+      "codeinjection_foot": null,
+      "codeinjection_head": null,
+      "collections": Array [
+        Object {
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
+          "description": null,
+          "feature_image": null,
+          "filter": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "posts": Array [
+            Object {
+              "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+              "sort_order": 0,
+            },
+          ],
+          "title": "Collection to remove.",
+          "type": "manual",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
+        },
+      ],
+      "comment_id": Any<String>,
+      "count": Object {
+        "clicks": 0,
+        "negative_feedback": 0,
+        "positive_feedback": 0,
+      },
+      "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+      "custom_excerpt": null,
+      "custom_template": null,
+      "email": null,
+      "email_only": false,
+      "email_segment": "all",
+      "email_subject": null,
+      "excerpt": null,
+      "feature_image": null,
+      "feature_image_alt": null,
+      "feature_image_caption": null,
+      "featured": false,
+      "frontmatter": null,
+      "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+      "meta_description": null,
+      "meta_title": null,
+      "mobiledoc": "{\\"version\\":\\"0.3.1\\",\\"ghostVersion\\":\\"4.0\\",\\"markups\\":[],\\"atoms\\":[],\\"cards\\":[],\\"sections\\":[[1,\\"p\\",[[0,[],0,\\"\\"]]]]}",
+      "newsletter": null,
+      "og_description": null,
+      "og_image": null,
+      "og_title": null,
+      "post_revisions": Any<Array>,
+      "primary_author": Any<Object>,
+      "primary_tag": Any<Object>,
+      "published_at": null,
+      "slug": "collection-update-test",
+      "status": "draft",
+      "tags": Any<Array>,
+      "tiers": Array [
+        Object {
+          "active": true,
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "currency": null,
+          "description": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "monthly_price": null,
+          "monthly_price_id": null,
+          "name": "Free",
+          "slug": "free",
+          "trial_days": 0,
+          "type": "free",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "visibility": "public",
+          "welcome_page_url": null,
+          "yearly_price": null,
+          "yearly_price_id": null,
+        },
+        Object {
+          "active": true,
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "currency": "usd",
+          "description": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "monthly_price": 500,
+          "monthly_price_id": null,
+          "name": "Default Product",
+          "slug": "default-product",
+          "trial_days": 0,
+          "type": "paid",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "visibility": "public",
+          "welcome_page_url": null,
+          "yearly_price": 5000,
+          "yearly_price_id": null,
+        },
+      ],
+      "title": "Collection update test",
+      "twitter_description": null,
+      "twitter_image": null,
+      "twitter_title": null,
+      "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+      "url": Any<String>,
+      "uuid": StringMatching /\\[a-f0-9\\]\\{8\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{12\\}/,
+      "visibility": "public",
+    },
+  ],
+}
+`;
+
+exports[`Posts API Update Can add and remove collections 4: [headers] 1`] = `
+Object {
+  "access-control-allow-origin": "http://127.0.0.1:2369",
+  "cache-control": "no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0",
+  "content-length": "3992",
+  "content-type": "application/json; charset=utf-8",
+  "content-version": StringMatching /v\\\\d\\+\\\\\\.\\\\d\\+/,
+  "etag": StringMatching /\\(\\?:W\\\\/\\)\\?"\\(\\?:\\[ !#-\\\\x7E\\\\x80-\\\\xFF\\]\\*\\|\\\\r\\\\n\\[\\\\t \\]\\|\\\\\\\\\\.\\)\\*"/,
+  "vary": "Accept-Version, Origin, Accept-Encoding",
+  "x-cache-invalidate": StringMatching /\\\\/p\\\\/\\[0-9a-f\\]\\{8\\}-\\[0-9a-f\\]\\{4\\}-\\[0-9a-f\\]\\{4\\}-\\[0-9a-f\\]\\{4\\}-\\[0-9a-f\\]\\{12\\}/,
+  "x-powered-by": "Express",
+}
+`;
+
+exports[`Posts API Update Can add and remove collections 5: [body] 1`] = `
+Object {
+  "posts": Array [
+    Object {
+      "authors": Any<Array>,
+      "canonical_url": null,
+      "codeinjection_foot": null,
+      "codeinjection_head": null,
+      "collections": Array [
+        Object {
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
+          "description": null,
+          "feature_image": null,
+          "filter": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "posts": Array [
+            Object {
+              "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+              "sort_order": 0,
+            },
+          ],
+          "title": "Collection to add.",
+          "type": "manual",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
+        },
+      ],
+      "comment_id": Any<String>,
+      "count": Object {
+        "clicks": 0,
+        "negative_feedback": 0,
+        "positive_feedback": 0,
+      },
+      "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+      "custom_excerpt": null,
+      "custom_template": null,
+      "email": null,
+      "email_only": false,
+      "email_segment": "all",
+      "email_subject": null,
+      "excerpt": null,
+      "feature_image": null,
+      "feature_image_alt": null,
+      "feature_image_caption": null,
+      "featured": false,
+      "frontmatter": null,
+      "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+      "meta_description": null,
+      "meta_title": null,
+      "mobiledoc": "{\\"version\\":\\"0.3.1\\",\\"ghostVersion\\":\\"4.0\\",\\"markups\\":[],\\"atoms\\":[],\\"cards\\":[],\\"sections\\":[[1,\\"p\\",[[0,[],0,\\"\\"]]]]}",
+      "newsletter": null,
+      "og_description": null,
+      "og_image": null,
+      "og_title": null,
+      "post_revisions": Any<Array>,
+      "primary_author": Any<Object>,
+      "primary_tag": Any<Object>,
+      "published_at": null,
+      "slug": "collection-update-test",
+      "status": "draft",
+      "tags": Any<Array>,
+      "tiers": Array [
+        Object {
+          "active": true,
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "currency": null,
+          "description": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "monthly_price": null,
+          "monthly_price_id": null,
+          "name": "Free",
+          "slug": "free",
+          "trial_days": 0,
+          "type": "free",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "visibility": "public",
+          "welcome_page_url": null,
+          "yearly_price": null,
+          "yearly_price_id": null,
+        },
+        Object {
+          "active": true,
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "currency": "usd",
+          "description": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "monthly_price": 500,
+          "monthly_price_id": null,
+          "name": "Default Product",
+          "slug": "default-product",
+          "trial_days": 0,
+          "type": "paid",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+          "visibility": "public",
+          "welcome_page_url": null,
+          "yearly_price": 5000,
+          "yearly_price_id": null,
+        },
+      ],
+      "title": "Collection update test",
+      "twitter_description": null,
+      "twitter_image": null,
+      "twitter_title": null,
+      "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.000Z/,
+      "url": Any<String>,
+      "uuid": StringMatching /\\[a-f0-9\\]\\{8\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{12\\}/,
+      "visibility": "public",
+    },
+  ],
+}
+`;
+
+exports[`Posts API Update Can add and remove collections 6: [headers] 1`] = `
+Object {
+  "access-control-allow-origin": "http://127.0.0.1:2369",
+  "cache-control": "no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0",
+  "content-length": "3989",
+  "content-type": "application/json; charset=utf-8",
+  "content-version": StringMatching /v\\\\d\\+\\\\\\.\\\\d\\+/,
+  "etag": StringMatching /\\(\\?:W\\\\/\\)\\?"\\(\\?:\\[ !#-\\\\x7E\\\\x80-\\\\xFF\\]\\*\\|\\\\r\\\\n\\[\\\\t \\]\\|\\\\\\\\\\.\\)\\*"/,
+  "vary": "Accept-Version, Origin, Accept-Encoding",
+  "x-cache-invalidate": StringMatching /\\\\/p\\\\/\\[0-9a-f\\]\\{8\\}-\\[0-9a-f\\]\\{4\\}-\\[0-9a-f\\]\\{4\\}-\\[0-9a-f\\]\\{4\\}-\\[0-9a-f\\]\\{12\\}/,
+  "x-powered-by": "Express",
+}
+`;
+
 exports[`Posts API Update Can update a post with lexical 1: [body] 1`] = `
 Object {
   "posts": Array [
diff --git a/ghost/core/test/e2e-api/admin/posts.test.js b/ghost/core/test/e2e-api/admin/posts.test.js
index c3a76a5285..700d8346d9 100644
--- a/ghost/core/test/e2e-api/admin/posts.test.js
+++ b/ghost/core/test/e2e-api/admin/posts.test.js
@@ -419,6 +419,80 @@ describe('Posts API', function () {
 
             mobiledocRevisions.length.should.equal(0);
         });
+
+        it('Can add and remove collections', async function () {
+            const {body: postBody} = await agent
+                .post('/posts/')
+                .body({
+                    posts: [{
+                        title: 'Collection update test'
+                    }]
+                })
+                .expectStatus(201)
+                .matchBodySnapshot({
+                    posts: [Object.assign({}, matchPostShallowIncludes, {published_at: null})]
+                })
+                .matchHeaderSnapshot({
+                    'content-version': anyContentVersion,
+                    etag: anyEtag,
+                    location: anyLocationFor('posts')
+                });
+
+            const [postResponse] = postBody.posts;
+
+            const {body: {
+                collections: [collectionToAdd]
+            }} = await agent
+                .post('/collections/')
+                .body({
+                    collections: [{
+                        title: 'Collection to add.'
+                    }]
+                });
+
+            const {body: {
+                collections: [collectionToRemove]
+            }} = await agent
+                .post('/collections/')
+                .body({
+                    collections: [{
+                        title: 'Collection to remove.'
+                    }]
+                });
+
+            const collectionMatcher = {
+                id: anyObjectId,
+                created_at: stringMatching(/\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z/),
+                updated_at: stringMatching(/\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z/),
+                posts: [{
+                    id: anyObjectId
+                }]
+            };
+
+            await agent.put(`/posts/${postResponse.id}/`)
+                .body({posts: [Object.assign({}, postResponse, {collections: [collectionToRemove.id]})]})
+                .expectStatus(200)
+                .matchBodySnapshot({
+                    posts: [Object.assign({}, matchPostShallowIncludes, {published_at: null}, {collections: [collectionMatcher]})]
+                })
+                .matchHeaderSnapshot({
+                    'content-version': anyContentVersion,
+                    etag: anyEtag,
+                    'x-cache-invalidate': stringMatching(/\/p\/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/)
+                });
+
+            await agent.put(`/posts/${postResponse.id}/`)
+                .body({posts: [Object.assign({}, postResponse, {collections: [collectionToAdd.id]})]})
+                .expectStatus(200)
+                .matchBodySnapshot({
+                    posts: [Object.assign({}, matchPostShallowIncludes, {published_at: null}, {collections: [collectionMatcher]})]
+                })
+                .matchHeaderSnapshot({
+                    'content-version': anyContentVersion,
+                    etag: anyEtag,
+                    'x-cache-invalidate': stringMatching(/\/p\/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/)
+                });
+        });
     });
 
     describe('Delete', function () {
diff --git a/ghost/posts-service/lib/PostsService.js b/ghost/posts-service/lib/PostsService.js
index e201fda9be..a432477efc 100644
--- a/ghost/posts-service/lib/PostsService.js
+++ b/ghost/posts-service/lib/PostsService.js
@@ -23,6 +23,7 @@ class PostsService {
         this.stats = stats;
         this.emailService = emailService;
         this.postsExporter = postsExporter;
+        /** @type {import('@tryghost/collections').CollectionsService} */
         this.collectionsService = collectionsService;
     }
 
@@ -44,7 +45,18 @@ class PostsService {
         return dto;
     }
 
-    async editPost(frame) {
+    /**
+     * @typedef {'published_updated' | 'scheduled_updated' | 'draft_updated' | 'unpublished'} EventString
+     */
+
+    /**
+     *
+     * @param {any} frame
+     * @param {object} [options]
+     * @param {(event: EventString, dto: any) => Promise<void> | void} [options.eventHandler] - Called before the editPost method resolves with an event string
+     * @returns
+     */
+    async editPost(frame, options) {
         // Make sure the newsletter is matching an active newsletter
         // Note that this option is simply ignored if the post isn't published or scheduled
         if (frame.options.newsletter && frame.options.email_segment) {
@@ -61,6 +73,49 @@ class PostsService {
             }
         }
 
+        if (this.isSet('collections') && frame.data.posts[0].collections) {
+            const existingCollections = await this.collectionsService.getCollectionsForPost(frame.options.id);
+            for (const collection of frame.data.posts[0].collections) {
+                let collectionId = null;
+                if (typeof collection === 'string') {
+                    collectionId = collection;
+                }
+                if (typeof collection?.id === 'string') {
+                    collectionId = collection.id;
+                }
+                if (!collectionId) {
+                    continue;
+                }
+                const existingCollection = existingCollections.find(c => c.id === collectionId);
+                if (existingCollection) {
+                    continue;
+                }
+                const found = await this.collectionsService.getById(collectionId);
+                if (!found) {
+                    continue;
+                }
+                if (found.type !== 'manual') {
+                    continue;
+                }
+                await this.collectionsService.addPostToCollection(collectionId, {
+                    id: frame.options.id,
+                    featured: frame.data.posts[0].featured,
+                    published_at: frame.data.posts[0].published_at
+                });
+            }
+            for (const existingCollection of existingCollections) {
+                if (frame.data.posts[0].collections.find((item) => {
+                    if (typeof item === 'string') {
+                        return item === existingCollection.id;
+                    }
+                    return item.id === existingCollection.id;
+                })) {
+                    continue;
+                }
+                await this.collectionsService.removePostFromCollection(existingCollection.id, frame.options.id);
+            }
+        }
+
         const model = await this.models.Post.edit(frame.data.posts[0], frame.options);
 
         /**Handle newsletter email */
@@ -82,7 +137,40 @@ class PostsService {
             }
         }
 
-        return model;
+        const dto = model.toJSON(frame.options);
+
+        if (this.isSet('collections')) {
+            if (frame?.original?.query?.include?.includes('collections') || frame.data.posts[0].collections) {
+                dto.collections = await this.collectionsService.getCollectionsForPost(model.id);
+            }
+        }
+
+        if (typeof options?.eventHandler === 'function') {
+            await options.eventHandler(this.getChanges(model), dto);
+        }
+
+        return dto;
+    }
+    /**
+     * @param {any} model
+     * @returns {EventString}
+     */
+    getChanges(model) {
+        if (model.get('status') === 'published' && model.wasChanged()) {
+            return 'published_updated';
+        }
+
+        if (model.get('status') === 'draft' && model.previous('status') === 'published') {
+            return 'unpublished';
+        }
+
+        if (model.get('status') === 'draft' && model.previous('status') !== 'published') {
+            return 'draft_updated';
+        }
+
+        if (model.get('status') === 'scheduled' && model.wasChanged()) {
+            return 'scheduled_updated';
+        }
     }
 
     #mergeFilters(...filters) {