diff --git a/src/api.rs b/src/api.rs
index c11467a..33960f1 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -1,10 +1,9 @@
 use crate::database::DatabaseHandle;
-
 use crate::error::MyResult;
-use crate::federation::activities::create_or_update_article::{
-    CreateOrUpdateArticle, CreateOrUpdateType,
-};
+use crate::federation::activities::create_article::CreateArticle;
+use crate::federation::activities::update_article::UpdateArticle;
 use crate::federation::objects::article::DbArticle;
+use crate::federation::objects::edit::DbEdit;
 use crate::federation::objects::instance::DbInstance;
 use activitypub_federation::config::Data;
 use activitypub_federation::fetch::object_id::ObjectId;
@@ -15,7 +14,6 @@ use axum::{Form, Json, Router};
 use axum_macros::debug_handler;
 use serde::{Deserialize, Serialize};
 use url::Url;
-use crate::federation::objects::edit::DbEdit;
 
 pub fn api_routes() -> Router {
     Router::new()
@@ -29,7 +27,7 @@ pub fn api_routes() -> Router {
 }
 
 #[derive(Deserialize, Serialize)]
-pub struct CreateArticle {
+pub struct CreateArticleData {
     pub title: String,
     pub text: String,
 }
@@ -38,7 +36,7 @@ pub struct CreateArticle {
 #[debug_handler]
 async fn create_article(
     data: Data<DatabaseHandle>,
-    Form(create_article): Form<CreateArticle>,
+    Form(create_article): Form<CreateArticleData>,
 ) -> MyResult<Json<DbArticle>> {
     let local_instance_id = data.local_instance().ap_id;
     let ap_id = Url::parse(&format!(
@@ -61,27 +59,21 @@ async fn create_article(
         articles.insert(article.ap_id.inner().clone(), article.clone());
     }
 
-    CreateOrUpdateArticle::send_to_local_followers(
-        article.clone(),
-        CreateOrUpdateType::Create,
-        &data,
-    )
-    .await?;
+    CreateArticle::send_to_followers(article.clone(), &data).await?;
 
     Ok(Json(article))
 }
 
 #[derive(Deserialize, Serialize)]
-pub struct EditArticle {
+pub struct EditArticleData {
     pub ap_id: ObjectId<DbArticle>,
     pub new_text: String,
 }
 
-// TODO: this should create an edit object
 #[debug_handler]
 async fn edit_article(
     data: Data<DatabaseHandle>,
-    Form(edit_article): Form<EditArticle>,
+    Form(edit_article): Form<EditArticleData>,
 ) -> MyResult<Json<DbArticle>> {
     let original_article = {
         let mut lock = data.articles.lock().unwrap();
@@ -93,28 +85,23 @@ async fn edit_article(
         let mut lock = data.articles.lock().unwrap();
         let article = lock.get_mut(edit_article.ap_id.inner()).unwrap();
         article.text = edit_article.new_text;
-        article.edits.push(edit);
+        article.edits.push(edit.clone());
         article.clone()
     };
 
-    CreateOrUpdateArticle::send_to_local_followers(
-        updated_article.clone(),
-        CreateOrUpdateType::Update,
-        &data,
-    )
-    .await?;
+    UpdateArticle::send_to_followers(updated_article.clone(), edit, &data).await?;
 
     Ok(Json(updated_article))
 }
 
 #[derive(Deserialize, Serialize, Clone)]
-pub struct GetArticle {
+pub struct GetArticleData {
     pub title: String,
 }
 
 #[debug_handler]
 async fn get_article(
-    Query(query): Query<GetArticle>,
+    Query(query): Query<GetArticleData>,
     data: Data<DatabaseHandle>,
 ) -> MyResult<Json<DbArticle>> {
     let articles = data.articles.lock().unwrap();
diff --git a/src/federation/activities/accept.rs b/src/federation/activities/accept.rs
index 487be2b..6bd3934 100644
--- a/src/federation/activities/accept.rs
+++ b/src/federation/activities/accept.rs
@@ -1,6 +1,6 @@
 use crate::error::MyResult;
 use crate::federation::objects::instance::DbInstance;
-use crate::utils::generate_object_id;
+use crate::utils::generate_activity_id;
 use crate::{database::DatabaseHandle, federation::activities::follow::Follow};
 use activitypub_federation::{
     config::Data, fetch::object_id::ObjectId, kinds::activity::AcceptType, traits::ActivityHandler,
@@ -20,7 +20,7 @@ pub struct Accept {
 
 impl Accept {
     pub fn new(actor: ObjectId<DbInstance>, object: Follow) -> MyResult<Accept> {
-        let id = generate_object_id(actor.inner())?;
+        let id = generate_activity_id(actor.inner())?;
         Ok(Accept {
             actor,
             object,
diff --git a/src/federation/activities/create_or_update_article.rs b/src/federation/activities/create_article.rs
similarity index 60%
rename from src/federation/activities/create_or_update_article.rs
rename to src/federation/activities/create_article.rs
index ae18080..fa869c5 100644
--- a/src/federation/activities/create_or_update_article.rs
+++ b/src/federation/activities/create_article.rs
@@ -2,7 +2,8 @@ use crate::database::DatabaseHandle;
 use crate::error::MyResult;
 use crate::federation::objects::article::{ApubArticle, DbArticle};
 use crate::federation::objects::instance::DbInstance;
-use crate::utils::generate_object_id;
+use crate::utils::generate_activity_id;
+use activitypub_federation::kinds::activity::CreateType;
 use activitypub_federation::{
     config::Data,
     fetch::object_id::ObjectId,
@@ -12,57 +13,41 @@ use activitypub_federation::{
 use serde::{Deserialize, Serialize};
 use url::Url;
 
-#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq)]
-pub enum CreateOrUpdateType {
-    Create,
-    Update,
-}
-
-// TODO: temporary placeholder, later rework this to send diffs
 #[derive(Deserialize, Serialize, Debug)]
 #[serde(rename_all = "camelCase")]
-pub struct CreateOrUpdateArticle {
+pub struct CreateArticle {
     pub actor: ObjectId<DbInstance>,
     #[serde(deserialize_with = "deserialize_one_or_many")]
     pub to: Vec<Url>,
     pub object: ApubArticle,
     #[serde(rename = "type")]
-    pub kind: CreateOrUpdateType,
+    pub kind: CreateType,
     pub id: Url,
 }
 
-impl CreateOrUpdateArticle {
-    pub async fn send_to_local_followers(
+impl CreateArticle {
+    pub async fn send_to_followers(
         article: DbArticle,
-        kind: CreateOrUpdateType,
         data: &Data<DatabaseHandle>,
     ) -> MyResult<()> {
         let local_instance = data.local_instance();
-        let to = local_instance
-            .followers
-            .iter()
-            .map(|f| f.ap_id.inner().clone())
-            .collect();
         let object = article.clone().into_json(data).await?;
-        let id = generate_object_id(local_instance.ap_id.inner())?;
-        let create_or_update = CreateOrUpdateArticle {
+        let id = generate_activity_id(local_instance.ap_id.inner())?;
+        let create_or_update = CreateArticle {
             actor: local_instance.ap_id.clone(),
-            to,
+            to: local_instance.follower_ids(),
             object,
-            kind,
+            kind: Default::default(),
             id,
         };
-        let inboxes = local_instance
-            .followers
-            .iter()
-            .map(|f| f.inbox.clone())
-            .collect();
-        local_instance.send(create_or_update, inboxes, data).await?;
+        local_instance
+            .send_to_followers(create_or_update, data)
+            .await?;
         Ok(())
     }
 }
 #[async_trait::async_trait]
-impl ActivityHandler for CreateOrUpdateArticle {
+impl ActivityHandler for CreateArticle {
     type DataType = DatabaseHandle;
     type Error = crate::error::Error;
 
diff --git a/src/federation/activities/follow.rs b/src/federation/activities/follow.rs
index ffab0ff..de156d9 100644
--- a/src/federation/activities/follow.rs
+++ b/src/federation/activities/follow.rs
@@ -1,6 +1,8 @@
 use crate::error::MyResult;
 use crate::federation::objects::instance::DbInstance;
-use crate::{database::DatabaseHandle, federation::activities::accept::Accept, generate_object_id};
+use crate::{
+    database::DatabaseHandle, federation::activities::accept::Accept, generate_activity_id,
+};
 use activitypub_federation::{
     config::Data,
     fetch::object_id::ObjectId,
@@ -22,7 +24,7 @@ pub struct Follow {
 
 impl Follow {
     pub fn new(actor: ObjectId<DbInstance>, object: ObjectId<DbInstance>) -> MyResult<Follow> {
-        let id = generate_object_id(actor.inner())?;
+        let id = generate_activity_id(actor.inner())?;
         Ok(Follow {
             actor,
             object,
diff --git a/src/federation/activities/mod.rs b/src/federation/activities/mod.rs
index b65cebb..a2cba29 100644
--- a/src/federation/activities/mod.rs
+++ b/src/federation/activities/mod.rs
@@ -1,3 +1,4 @@
 pub mod accept;
-pub mod create_or_update_article;
+pub mod create_article;
 pub mod follow;
+pub mod update_article;
diff --git a/src/federation/activities/update_article.rs b/src/federation/activities/update_article.rs
new file mode 100644
index 0000000..60edb36
--- /dev/null
+++ b/src/federation/activities/update_article.rs
@@ -0,0 +1,80 @@
+use crate::database::DatabaseHandle;
+use crate::error::MyResult;
+use crate::federation::objects::article::DbArticle;
+use crate::federation::objects::edit::{ApubEdit, DbEdit};
+use crate::federation::objects::instance::DbInstance;
+use crate::utils::generate_activity_id;
+use activitypub_federation::kinds::activity::CreateType;
+use activitypub_federation::{
+    config::Data,
+    fetch::object_id::ObjectId,
+    protocol::helpers::deserialize_one_or_many,
+    traits::{ActivityHandler, Object},
+};
+use diffy::{apply, Patch};
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+#[derive(Deserialize, Serialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct UpdateArticle {
+    pub actor: ObjectId<DbInstance>,
+    #[serde(deserialize_with = "deserialize_one_or_many")]
+    pub to: Vec<Url>,
+    pub object: ObjectId<DbArticle>,
+    pub result: ApubEdit,
+    #[serde(rename = "type")]
+    pub kind: CreateType,
+    pub id: Url,
+}
+
+impl UpdateArticle {
+    pub async fn send_to_followers(
+        article: DbArticle,
+        edit: DbEdit,
+        data: &Data<DatabaseHandle>,
+    ) -> MyResult<()> {
+        let local_instance = data.local_instance();
+        let id = generate_activity_id(local_instance.ap_id.inner())?;
+        let create_or_update = UpdateArticle {
+            actor: local_instance.ap_id.clone(),
+            to: local_instance.follower_ids(),
+            object: article.ap_id,
+            result: edit.into_json(data).await?,
+            kind: Default::default(),
+            id,
+        };
+        local_instance
+            .send_to_followers(create_or_update, data)
+            .await?;
+        Ok(())
+    }
+}
+#[async_trait::async_trait]
+impl ActivityHandler for UpdateArticle {
+    type DataType = DatabaseHandle;
+    type Error = crate::error::Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let edit = DbEdit::from_json(self.result.clone(), data).await?;
+        let mut lock = data.articles.lock().unwrap();
+        let article = lock.get_mut(self.object.inner()).unwrap();
+        article.edits.push(edit);
+        // TODO: probably better to apply patch inside DbEdit::from_json()
+        let patch = Patch::from_str(&self.result.diff)?;
+        article.text = apply(&article.text, &patch)?;
+        Ok(())
+    }
+}
diff --git a/src/federation/diff.rs b/src/federation/diff.rs
deleted file mode 100644
index 6108c10..0000000
--- a/src/federation/diff.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-#[test]
-fn test_diff() {
-    use diffy::create_patch;
-
-    let original = "The Way of Kings\nWords of Radiance\n";
-    let modified = "The Way of Kings\nWords of Radiance\nOathbringer\n";
-
-    let patch = create_patch(original, modified);
-    assert_eq!("--- original\n+++ modified\n@@ -1,2 +1,3 @@\n The Way of Kings\n Words of Radiance\n+Oathbringer\n", patch.to_string());
-}
diff --git a/src/federation/mod.rs b/src/federation/mod.rs
index 2d88170..e451aa0 100644
--- a/src/federation/mod.rs
+++ b/src/federation/mod.rs
@@ -9,7 +9,6 @@ use std::sync::{Arc, Mutex};
 use url::Url;
 
 pub mod activities;
-mod diff;
 pub mod objects;
 pub mod routes;
 
diff --git a/src/federation/objects/edit.rs b/src/federation/objects/edit.rs
index cadb9b6..2b12182 100644
--- a/src/federation/objects/edit.rs
+++ b/src/federation/objects/edit.rs
@@ -6,8 +6,8 @@ use activitypub_federation::fetch::object_id::ObjectId;
 use activitypub_federation::traits::Object;
 use diffy::create_patch;
 use serde::{Deserialize, Serialize};
+use sha2::Digest;
 use sha2::Sha224;
-use sha2::{Digest};
 use url::Url;
 
 /// Represents a single change to the article.
@@ -28,7 +28,7 @@ impl DbEdit {
         Ok(DbEdit {
             id: edit_id,
             diff: diff.to_string(),
-            local: true
+            local: true,
         })
     }
 }
@@ -44,7 +44,7 @@ pub struct ApubEdit {
     #[serde(rename = "type")]
     kind: EditType,
     id: ObjectId<DbEdit>,
-    diff: String,
+    pub(crate) diff: String,
 }
 
 #[async_trait::async_trait]
diff --git a/src/federation/objects/edits_collection.rs b/src/federation/objects/edits_collection.rs
index e6fda59..1eeaaa9 100644
--- a/src/federation/objects/edits_collection.rs
+++ b/src/federation/objects/edits_collection.rs
@@ -75,7 +75,11 @@ impl Collection for DbEditCollection {
             try_join_all(apub.items.into_iter().map(|i| DbEdit::from_json(i, data))).await?;
         let mut articles = data.articles.lock().unwrap();
         let article = articles.get_mut(owner.ap_id.inner()).unwrap();
-        let edit_ids = article.edits.iter().map(|e| e.id.clone()).collect::<Vec<_>>();
+        let edit_ids = article
+            .edits
+            .iter()
+            .map(|e| e.id.clone())
+            .collect::<Vec<_>>();
         for e in edits.clone() {
             if !edit_ids.contains(&&e.id) {
                 article.edits.push(e);
diff --git a/src/federation/objects/instance.rs b/src/federation/objects/instance.rs
index c46cbec..f624105 100644
--- a/src/federation/objects/instance.rs
+++ b/src/federation/objects/instance.rs
@@ -1,4 +1,4 @@
-use crate::error::Error;
+use crate::error::{Error, MyResult};
 use crate::federation::objects::articles_collection::DbArticleCollection;
 use crate::{database::DatabaseHandle, federation::activities::follow::Follow};
 use activitypub_federation::activity_sending::SendActivityTask;
@@ -40,10 +40,17 @@ pub struct Instance {
 }
 
 impl DbInstance {
-    pub fn followers_url(&self) -> Result<Url, Error> {
+    pub fn followers_url(&self) -> MyResult<Url> {
         Ok(Url::parse(&format!("{}/followers", self.ap_id.inner()))?)
     }
 
+    pub fn follower_ids(&self) -> Vec<Url> {
+        self.followers
+            .iter()
+            .map(|f| f.ap_id.inner().clone())
+            .collect()
+    }
+
     pub async fn follow(
         &self,
         other: &DbInstance,
@@ -55,7 +62,26 @@ impl DbInstance {
         Ok(())
     }
 
-    pub(crate) async fn send<Activity>(
+    pub async fn send_to_followers<Activity>(
+        &self,
+        activity: Activity,
+        data: &Data<DatabaseHandle>,
+    ) -> Result<(), <Activity as ActivityHandler>::Error>
+    where
+        Activity: ActivityHandler + Serialize + Debug + Send + Sync,
+        <Activity as ActivityHandler>::Error: From<activitypub_federation::error::Error>,
+    {
+        let local_instance = data.local_instance();
+        let inboxes = local_instance
+            .followers
+            .iter()
+            .map(|f| f.inbox.clone())
+            .collect();
+        local_instance.send(activity, inboxes, data).await?;
+        Ok(())
+    }
+
+    pub async fn send<Activity>(
         &self,
         activity: Activity,
         recipients: Vec<Url>,
diff --git a/src/federation/routes.rs b/src/federation/routes.rs
index bd0cb57..b65b50a 100644
--- a/src/federation/routes.rs
+++ b/src/federation/routes.rs
@@ -12,7 +12,8 @@ use activitypub_federation::traits::Object;
 use activitypub_federation::traits::{ActivityHandler, Collection};
 use axum::extract::Path;
 
-use crate::federation::activities::create_or_update_article::CreateOrUpdateArticle;
+use crate::federation::activities::create_article::CreateArticle;
+use crate::federation::activities::update_article::UpdateArticle;
 use crate::federation::objects::article::ApubArticle;
 use crate::federation::objects::articles_collection::{ArticleCollection, DbArticleCollection};
 use crate::federation::objects::edits_collection::{ApubEditCollection, DbEditCollection};
@@ -82,7 +83,8 @@ async fn http_get_article_edits(
 pub enum InboxActivities {
     Follow(Follow),
     Accept(Accept),
-    CreateOrUpdateArticle(CreateOrUpdateArticle),
+    CreateArticle(CreateArticle),
+    UpdateArticle(UpdateArticle),
 }
 
 #[debug_handler]
diff --git a/src/lib.rs b/src/lib.rs
index c7f29f2..18614af 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-use crate::utils::generate_object_id;
+use crate::utils::generate_activity_id;
 
 use activitypub_federation::config::FederationMiddleware;
 use axum::{Router, Server};
diff --git a/src/utils.rs b/src/utils.rs
index 03a0b28..65add18 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -1,9 +1,7 @@
 use rand::{distributions::Alphanumeric, thread_rng, Rng};
 use url::{ParseError, Url};
 
-/// Just generate random url as object id. In a real project, you probably want to use
-/// an url which contains the database id for easy retrieval (or store the random id in db).
-pub fn generate_object_id(domain: &Url) -> Result<Url, ParseError> {
+pub fn generate_activity_id(domain: &Url) -> Result<Url, ParseError> {
     let port = domain.port().unwrap();
     let domain = domain.domain().unwrap();
     let id: String = thread_rng()
@@ -11,5 +9,5 @@ pub fn generate_object_id(domain: &Url) -> Result<Url, ParseError> {
         .take(7)
         .map(char::from)
         .collect();
-    Url::parse(&format!("http://{}:{}/objects/{}", domain,port, id))
+    Url::parse(&format!("http://{}:{}/objects/{}", domain, port, id))
 }
diff --git a/tests/test.rs b/tests/test.rs
index 7278455..3d6f2ce 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -4,7 +4,7 @@ mod common;
 
 use crate::common::{follow_instance, get_query, patch, post, TestData};
 use common::get;
-use fediwiki::api::{CreateArticle, EditArticle, GetArticle, ResolveObject};
+use fediwiki::api::{CreateArticleData, EditArticleData, GetArticleData, ResolveObject};
 use fediwiki::error::MyResult;
 use fediwiki::federation::objects::article::DbArticle;
 use fediwiki::federation::objects::instance::DbInstance;
@@ -17,7 +17,7 @@ async fn test_create_and_read_article() -> MyResult<()> {
     let data = TestData::start();
 
     // error on nonexistent article
-    let get_article = GetArticle {
+    let get_article = GetArticleData {
         title: "Manu_Chao".to_string(),
     };
     let not_found = get_query::<DbArticle, _>(
@@ -29,7 +29,7 @@ async fn test_create_and_read_article() -> MyResult<()> {
     assert!(not_found.is_err());
 
     // create article
-    let create_article = CreateArticle {
+    let create_article = CreateArticleData {
         title: get_article.title.to_string(),
         text: "Lorem ipsum".to_string(),
     };
@@ -80,7 +80,7 @@ async fn test_synchronize_articles() -> MyResult<()> {
     let data = TestData::start();
 
     // create article on alpha
-    let create_article = CreateArticle {
+    let create_article = CreateArticleData {
         title: "Manu_Chao".to_string(),
         text: "Lorem ipsum".to_string(),
     };
@@ -89,7 +89,7 @@ async fn test_synchronize_articles() -> MyResult<()> {
     assert!(create_res.local);
 
     // article is not yet on beta
-    let get_article = GetArticle {
+    let get_article = GetArticleData {
         title: "Manu_Chao".to_string(),
     };
     let get_res = get_query::<DbArticle, _>(
@@ -129,7 +129,7 @@ async fn test_federate_article_changes() -> MyResult<()> {
     follow_instance(data.hostname_alpha, data.hostname_beta).await?;
 
     // create new article
-    let create_form = CreateArticle {
+    let create_form = CreateArticleData {
         title: "Manu_Chao".to_string(),
         text: "Lorem ipsum".to_string(),
     };
@@ -137,7 +137,7 @@ async fn test_federate_article_changes() -> MyResult<()> {
     assert_eq!(create_res.title, create_form.title);
 
     // article should be federated to alpha
-    let get_article = GetArticle {
+    let get_article = GetArticleData {
         title: create_res.title.clone(),
     };
     let get_res =
@@ -147,17 +147,20 @@ async fn test_federate_article_changes() -> MyResult<()> {
     assert_eq!(create_res.text, get_res.text);
 
     // edit the article
-    let edit_form = EditArticle {
+    let edit_form = EditArticleData {
         ap_id: create_res.ap_id,
         new_text: "Lorem Ipsum 2".to_string(),
     };
     let edit_res: DbArticle = patch(data.hostname_beta, "article", &edit_form).await?;
     assert_eq!(edit_res.text, edit_form.new_text);
     assert_eq!(edit_res.edits.len(), 1);
-    assert!(edit_res.edits[0].id.to_string().starts_with(&edit_res.ap_id.to_string()));
+    assert!(edit_res.edits[0]
+        .id
+        .to_string()
+        .starts_with(&edit_res.ap_id.to_string()));
 
     // edit should be federated to alpha
-    let get_article = GetArticle {
+    let get_article = GetArticleData {
         title: edit_res.title.clone(),
     };
     let get_res =