diff --git a/src/main.rs b/src/main.rs
index 233ccf4..70d7976 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -69,12 +69,21 @@ async fn main() {
     });
 
     let (router, mut api) = OpenApiRouter::new()
+        // Book API
         .routes(routes!(routes::book::get_book_by_ean))
         .routes(routes!(routes::book::get_book_by_id))
+        // Book Instance API
         .routes(routes!(routes::book_instance::get_book_instance_by_id))
         .routes(routes!(routes::book_instance::create_book_instance))
+        .routes(routes!(routes::book_instance::update_book_instance))
+        .routes(routes!(routes::book_instance::sell_book_instance))
+        .routes(routes!(routes::book_instance::bulk_create_book_instance))
+        // Owner API
         .routes(routes!(routes::owner::get_owner_by_id))
         .routes(routes!(routes::owner::create_owner))
+        .routes(routes!(routes::owner::update_owner))
+        .routes(routes!(routes::owner::get_owners))
+        // Misc
         .routes(routes!(routes::websocket::ws_handler))
         .route("/", get(index))
         .with_state(shared_state)
diff --git a/src/routes/book_instance.rs b/src/routes/book_instance.rs
index eb635a8..9eb8bea 100644
--- a/src/routes/book_instance.rs
+++ b/src/routes/book_instance.rs
@@ -17,7 +17,7 @@ struct BookInstanceByIdParams(u32);
 #[axum::debug_handler]
 #[utoipa::path(
     get,
-    path = "/book_instance/id/{id}",
+    path = "/book_instance/{id}",
     params(BookInstanceByIdParams),
     responses(
         (status = OK, body = book_instance::Model, description = "Found book instance with corresponding ID in the database"),
@@ -79,3 +79,140 @@ pub async fn create_book_instance(
         Ok(res) => (StatusCode::OK, Json(Some(res.try_into_model().expect("All fields should be set once the book instance is saved"))))
     }
 }
+
+#[derive(Deserialize, Serialize, utoipa::ToSchema)]
+pub struct BookInstanceUpdateParams {
+    status: Option<book_instance::BookStatus>,
+    owner_id: Option<u32>,
+    price: Option<i32>,
+}
+
+#[axum::debug_handler]
+#[utoipa::path(
+    patch,
+    path = "/book_instance/{id}",
+    params(BookInstanceByIdParams),
+    request_body = BookInstanceUpdateParams,
+    responses(
+        (status = OK, body = book_instance::Model, description = "Successfully updated book instance"),
+        (status = NOT_FOUND, description = "No book instance with specified id was found"),
+    ),
+    summary = "Update a book instance",
+    description = "Update a book instance",
+    tag = "book-instance-api",
+)]
+pub async fn update_book_instance(
+    State(state): State<Arc<AppState>>,
+    Path(id): Path<u32>,
+    Json(instance_payload): Json<BookInstanceUpdateParams>,
+) -> (StatusCode, Json<Option<book_instance::Model>>) {
+
+    if let Ok(Some(book_instance)) = BookInstance::find_by_id(id).one(state.db_conn.as_ref()).await {
+        let mut book_instance: book_instance::ActiveModel = book_instance.into();
+        book_instance.price = match instance_payload.price {
+            None => book_instance.price,
+            Some(v) => Set(v)
+        };
+        book_instance.owner_id = match instance_payload.owner_id {
+            None => book_instance.owner_id,
+            Some(v) => Set(v)
+        };
+        book_instance.status = match instance_payload.status {
+            None => book_instance.status,
+            Some(v) => Set(v)
+        };
+        
+        match book_instance.update(state.db_conn.as_ref()).await {
+            Err(e) => {
+                log::error!(target: "api", "Error while updating book instance from api: {:#?}", e);
+                (StatusCode::INTERNAL_SERVER_ERROR, Json(None))
+            },
+            Ok(res) => {
+                let model = res.try_into_model().expect("All fields should be set once the book instance is saved");
+                (StatusCode::OK, Json(Some(model)))
+            }
+        }
+    } else {
+        (StatusCode::NOT_FOUND, Json(None))
+    }
+}
+
+#[derive(Deserialize, Serialize, utoipa::ToSchema)]
+pub struct BookInstanceSaleParams {
+    price: i32,
+}
+
+#[axum::debug_handler]
+#[utoipa::path(
+    post,
+    path = "/book_instance/{id}/sell",
+    params(BookInstanceByIdParams),
+    request_body = BookInstanceSaleParams,
+    responses(
+        (status = OK, body = book_instance::Model, description = "Successfully sold book instance"),
+        (status = NOT_FOUND, description = "No book instance with specified id was found"),
+    ),
+    summary = "Sell a book instance",
+    description = "Sell a book instance",
+    tag = "book-instance-api",
+)]
+pub async fn sell_book_instance(
+    State(state): State<Arc<AppState>>,
+    Path(id): Path<u32>,
+    Json(instance_payload): Json<BookInstanceSaleParams>,
+) -> (StatusCode, Json<Option<book_instance::Model>>) {
+
+    if let Ok(Some(book_instance)) = BookInstance::find_by_id(id).one(state.db_conn.as_ref()).await {
+        let mut book_instance: book_instance::ActiveModel = book_instance.into();
+        book_instance.sold_price = Set(Some(instance_payload.price));
+        book_instance.status = Set(book_instance::BookStatus::Sold);
+        
+        match book_instance.update(state.db_conn.as_ref()).await {
+            Err(e) => {
+                log::error!(target: "api", "Error while selling book instance from api: {:#?}", e);
+                (StatusCode::INTERNAL_SERVER_ERROR, Json(None))
+            },
+            Ok(res) => {
+                let model = res.try_into_model().expect("All fields should be set once the book instance is saved");
+                (StatusCode::OK, Json(Some(model)))
+            }
+        }
+    } else {
+        (StatusCode::NOT_FOUND, Json(None))
+    }
+}
+#[axum::debug_handler]
+#[utoipa::path(
+    post,
+    path = "/book_instance/bulk",
+    request_body = Vec<BookInstanceCreateParams>,
+    responses(
+        (status = OK, description = "Successfully created book instances"),
+    ),
+    summary = "Create new book instances in bulk",
+    description = "Create new book instances in bulk",
+    tag = "book-instance-api",
+)]
+pub async fn bulk_create_book_instance(
+    State(state): State<Arc<AppState>>,
+    Json(instance_payload): Json<Vec<BookInstanceCreateParams>>,
+) -> StatusCode {
+
+    let instances = instance_payload
+        .into_iter()
+        .map(|p| book_instance::ActiveModel {
+            book_id: Set(p.book_id),
+            owner_id: Set(p.owner_id),
+            price: Set(p.price),
+            status: Set(book_instance::BookStatus::Available),
+            ..Default::default()
+        });
+
+    match BookInstance::insert_many(instances).exec(state.db_conn.as_ref()).await {
+        Err(e) => {
+            log::error!(target: "api", "Error while bulk inserting new book instances: {:#?}", e);
+            StatusCode::INTERNAL_SERVER_ERROR
+        },
+        Ok(_) => StatusCode::OK
+    }
+}
diff --git a/src/routes/owner.rs b/src/routes/owner.rs
index 85bee5f..0ba5c6c 100644
--- a/src/routes/owner.rs
+++ b/src/routes/owner.rs
@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use axum::{extract::{Path, State}, Json};
 use reqwest::{StatusCode};
-use sea_orm::{ActiveModelTrait, ActiveValue::{NotSet, Set}, EntityTrait, TryIntoModel};
+use sea_orm::{ActiveModelTrait, ActiveValue::{NotSet, Set, Unchanged}, EntityTrait, TryIntoModel};
 use serde::{Deserialize, Serialize};
 use utoipa::IntoParams;
 
@@ -82,3 +82,86 @@ pub async fn create_owner(
         }
     }
 }
+
+#[derive(Deserialize, Serialize, utoipa::ToSchema)]
+pub struct OwnerUpdateParams {
+    first_name: Option<String>,
+    last_name: Option<String>,
+    contact: Option<String>
+}
+
+#[axum::debug_handler]
+#[utoipa::path(
+    patch,
+    path = "/owner/{id}",
+    params(OwnerByIdParams),
+    request_body = OwnerUpdateParams,
+    responses(
+        (status = OK, body = owner::Model, description = "Successfully updated owner"),
+        (status = NOT_FOUND, description = "No owner with this id exists in the database")
+    ),
+    summary = "Update an owner",
+    description = "Update an owner",
+    tag = "owner-api",
+)]
+pub async fn update_owner(
+    State(state): State<Arc<AppState>>,
+    Path(id): Path<u32>,
+    Json(instance_payload): Json<OwnerUpdateParams>,
+) -> (StatusCode, Json<Option<owner::Model>>) {
+
+    if let Ok(Some(owner)) = Owner::find_by_id(id).one(state.db_conn.as_ref()).await {
+        let mut owner: owner::ActiveModel = owner.into();
+        owner.first_name = match instance_payload.first_name {
+            None => owner.first_name,
+            Some(v) => Set(v)
+        };
+        owner.last_name = match instance_payload.last_name {
+            None => owner.last_name,
+            Some(v) => Set(v)
+        };
+        owner.contact = match instance_payload.contact {
+            None => owner.contact,
+            Some(v) => Set(v)
+        };
+        
+        match owner.update(state.db_conn.as_ref()).await {
+            Err(e) => {
+                log::error!(target: "api", "Error while updating owner from api: {:#?}", e);
+                (StatusCode::INTERNAL_SERVER_ERROR, Json(None))
+            },
+            Ok(res) => {
+                let model = res.try_into_model().expect("All fields should be set once the owner is saved");
+                let _ = state.event_bus.send(Event::WebsocketBroadcast(WebsocketMessage::NewOwner(Arc::new(model.clone()))));
+                (StatusCode::OK, Json(Some(model)))
+            }
+        }
+    } else {
+        (StatusCode::NOT_FOUND, Json(None))
+    }
+}
+
+#[axum::debug_handler]
+#[utoipa::path(
+    get,
+    path = "/owners",
+    responses(
+        (status = OK, body = Vec<owner::Model>, description = "List of owners"),
+    ),
+    summary = "List book owners",
+    description = "List book owners",
+    tag = "owner-api",
+)]
+pub async fn get_owners(
+    State(state): State<Arc<AppState>>,
+) -> (StatusCode, Json<Option<Vec<owner::Model>>>) {
+    match Owner::find().all(state.db_conn.as_ref()).await {
+        Err(e) => {
+            log::error!(target: "api", "Error while getting owner list: {:#?}", e);
+            (StatusCode::INTERNAL_SERVER_ERROR, Json(None))
+        }
+        Ok(owners) => {
+            (StatusCode::OK, Json(Some(owners)))
+        }
+    }
+}
diff --git a/src/routes/websocket.rs b/src/routes/websocket.rs
index 8590755..264697a 100644
--- a/src/routes/websocket.rs
+++ b/src/routes/websocket.rs
@@ -5,9 +5,8 @@ use axum::{
         ws::{Message, Utf8Bytes, WebSocket, WebSocketUpgrade},
         ConnectInfo,
         State
-    }, http, response::IntoResponse
+    }, response::IntoResponse
 };
-use reqwest::StatusCode;
 
 use crate::{utils::events, AppState};
 
@@ -73,6 +72,7 @@ async fn handle_socket(mut socket: WebSocket, who: SocketAddr, state: Arc<AppSta
                 Ok(event) => {
                     match event {
                         events::Event::WebsocketBroadcast(message) => {
+                            log::debug!(target: "websocket", "Sent {message:?} to {who}");
                             let _ = sender.send(Message::Text(Utf8Bytes::from(message.to_json().to_string()))).await;
                         }
                     }
diff --git a/src/utils/events.rs b/src/utils/events.rs
index 6ca8285..1715fa3 100644
--- a/src/utils/events.rs
+++ b/src/utils/events.rs
@@ -9,7 +9,7 @@ pub enum Event {
     WebsocketBroadcast(WebsocketMessage)
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum WebsocketMessage {
     NewOwner(Arc<owner::Model>)
 }