diff --git a/migrations/2025-03-21-212723_create_fcm/up.sql b/migrations/2025-03-21-212723_create_fcm/up.sql
index 218a90d..2611912 100644
--- a/migrations/2025-03-21-212723_create_fcm/up.sql
+++ b/migrations/2025-03-21-212723_create_fcm/up.sql
@@ -2,5 +2,5 @@ CREATE TABLE fcm
 (
     user_id text PRIMARY KEY NOT NULL REFERENCES users (id),
     token   text             NOT NULL,
-    topics  text[]           NOT NULL
+    topics  text[]           NOT NULL CHECK ( array_position(topics, null) is null )
 );
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 1291311..7c1cc74 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -50,7 +50,8 @@ pub fn get_api_scope<
 
     let fcm_scope = utoipa_actix_web::scope("/fcm")
         .wrap(JWTAuthorization)
-        .service(routes::fcm::update_callback);
+        .service(routes::fcm::update_callback)
+        .service(routes::fcm::set_token);
 
     let vk_id_scope = utoipa_actix_web::scope("/vkid") //
         .service(routes::vk_id::oauth);
diff --git a/src/routes/fcm/mod.rs b/src/routes/fcm/mod.rs
index c7b4780..b422206 100644
--- a/src/routes/fcm/mod.rs
+++ b/src/routes/fcm/mod.rs
@@ -1,3 +1,5 @@
 mod update_callback;
+mod set_token;
 
 pub use update_callback::*;
+pub use set_token::*;
diff --git a/src/routes/fcm/set_token.rs b/src/routes/fcm/set_token.rs
new file mode 100644
index 0000000..6ce1faf
--- /dev/null
+++ b/src/routes/fcm/set_token.rs
@@ -0,0 +1,112 @@
+use crate::app_state::AppState;
+use crate::database;
+use crate::database::models::FCM;
+use crate::extractors::authorized_user::UserExtractor;
+use crate::extractors::base::SyncExtractor;
+use crate::utility::mutex::{MutexScope, MutexScopeAsync};
+use actix_web::{HttpResponse, Responder, patch, web};
+use diesel::{RunQueryDsl, SaveChangesDsl};
+use firebase_messaging_rs::FCMClient;
+use firebase_messaging_rs::topic::{TopicManagementError, TopicManagementSupport};
+use serde::Deserialize;
+
+#[derive(Debug, Deserialize)]
+struct Params {
+    pub token: String,
+}
+
+async fn get_fcm(
+    app_state: &web::Data<AppState>,
+    user_data: &UserExtractor<true>,
+    token: String,
+) -> Result<FCM, diesel::result::Error> {
+    match user_data.fcm() {
+        Some(fcm) => {
+            let mut fcm = fcm.clone();
+            fcm.token = token;
+
+            Ok(fcm)
+        }
+        None => {
+            let fcm = FCM {
+                user_id: user_data.user().id.clone(),
+                token,
+                topics: vec![],
+            };
+
+            match app_state.database.scope(|conn| {
+                diesel::insert_into(database::schema::fcm::table)
+                    .values(&fcm)
+                    .execute(conn)
+            }) {
+                Ok(_) => Ok(fcm),
+                Err(e) => Err(e),
+            }
+        }
+    }
+}
+
+#[utoipa::path(responses((status = OK)))]
+#[patch("/set-token")]
+pub async fn set_token(
+    app_state: web::Data<AppState>,
+    web::Query(params): web::Query<Params>,
+    user_data: SyncExtractor<UserExtractor<true>>,
+) -> impl Responder {
+    let user_data = user_data.into_inner();
+
+    // If token not changes - exit.
+    if let Some(fcm) = user_data.fcm() {
+        if fcm.token == params.token {
+            return HttpResponse::Ok();
+        }
+    }
+
+    let fcm = get_fcm(&app_state, &user_data, params.token.clone()).await;
+    if let Err(e) = fcm {
+        eprintln!("Failed to get FCM: {e}");
+        return HttpResponse::Ok();
+    }
+
+    let mut fcm = fcm.ok().unwrap();
+
+    // Add default topics.
+    if !fcm.topics.contains(&Some("common".to_string())) {
+        fcm.topics.push(Some("common".to_string()));
+    }
+
+    // Subscribe to default topics.
+    if let Some(e) = app_state
+        .fcm_client
+        .async_scope(
+            async |client: &mut FCMClient| -> Result<(), TopicManagementError> {
+                let mut tokens: Vec<String> = Vec::new();
+                tokens.push(fcm.token.clone());
+
+                for topic in fcm.topics.clone() {
+                    if let Some(topic) = topic {
+                        client.register_tokens_to_topic(topic.clone(), tokens.clone()).await?;
+                    }
+                }
+
+                Ok(())
+            },
+        )
+        .await
+        .err()
+    {
+        eprintln!("Failed to subscribe token to topic: {:?}", e);
+        return HttpResponse::Ok();
+    }
+
+    // Write updates to db.
+    if let Some(e) = app_state
+        .database
+        .scope(|conn| fcm.save_changes::<FCM>(conn))
+        .err()
+    {
+        eprintln!("Failed to update FCM object: {e}");
+    }
+
+    HttpResponse::Ok()
+}