diff --git a/services/backup/src/service/handlers/add_attachments.rs b/services/backup/src/service/handlers/add_attachments.rs
new file mode 100644
index 000000000..f326a82c6
--- /dev/null
+++ b/services/backup/src/service/handlers/add_attachments.rs
@@ -0,0 +1,11 @@
+use tonic::Status;
+
+use super::proto;
+use crate::database::DatabaseClient;
+
+pub async fn handle_add_attachments(
+  db: &DatabaseClient,
+  request: proto::AddAttachmentsRequest,
+) -> Result<(), Status> {
+  unimplemented!()
+}
diff --git a/services/backup/src/service/mod.rs b/services/backup/src/service/mod.rs
index f8744f98a..b8eeada36 100644
--- a/services/backup/src/service/mod.rs
+++ b/services/backup/src/service/mod.rs
@@ -1,167 +1,184 @@
 use aws_sdk_dynamodb::Error as DynamoDBError;
 use proto::backup_service_server::BackupService;
 use std::pin::Pin;
 use tokio::sync::mpsc;
 use tokio_stream::{wrappers::ReceiverStream, Stream, StreamExt};
 use tonic::{Request, Response, Status};
 use tracing::{debug, error, info, instrument, trace, warn, Instrument};
 
 use crate::{
   constants::MPSC_CHANNEL_BUFFER_CAPACITY,
   database::{DatabaseClient, Error as DBError},
 };
 
 mod proto {
   tonic::include_proto!("backup");
 }
 pub use proto::backup_service_server::BackupServiceServer;
 
 /// submodule containing gRPC endpoint handler implementations
 mod handlers {
+  pub(super) mod add_attachments;
   pub(super) mod create_backup;
 
   // re-exports for convenient usage in handlers
   pub(self) use super::handle_db_error;
   pub(self) use super::proto;
 }
 use self::handlers::create_backup::CreateBackupHandler;
 
 pub struct MyBackupService {
   db: DatabaseClient,
 }
 
 impl MyBackupService {
   pub fn new(db_client: DatabaseClient) -> Self {
     MyBackupService { db: db_client }
   }
 }
 
 // gRPC implementation
 #[tonic::async_trait]
 impl BackupService for MyBackupService {
   type CreateNewBackupStream = Pin<
     Box<
       dyn Stream<Item = Result<proto::CreateNewBackupResponse, Status>> + Send,
     >,
   >;
 
   #[instrument(skip_all, fields(device_id, data_hash, backup_id, blob_holder))]
   async fn create_new_backup(
     &self,
     request: Request<tonic::Streaming<proto::CreateNewBackupRequest>>,
   ) -> Result<Response<Self::CreateNewBackupStream>, Status> {
     use proto::create_new_backup_request::Data::*;
 
     info!("CreateNewBackup request: {:?}", request);
     let mut in_stream = request.into_inner();
     let (tx, rx) = mpsc::channel(MPSC_CHANNEL_BUFFER_CAPACITY);
     let db = self.db.clone();
     let worker = async move {
       let mut handler = CreateBackupHandler::new(&db);
       while let Some(message) = in_stream.next().await {
         let response = match message {
           Ok(proto::CreateNewBackupRequest {
             data: Some(UserId(user_id)),
           }) => handler.handle_user_id(user_id).await,
           Ok(proto::CreateNewBackupRequest {
             data: Some(DeviceId(device_id)),
           }) => handler.handle_device_id(device_id).await,
           Ok(proto::CreateNewBackupRequest {
             data: Some(KeyEntropy(key_entropy)),
           }) => handler.handle_key_entropy(key_entropy).await,
           Ok(proto::CreateNewBackupRequest {
             data: Some(NewCompactionHash(hash)),
           }) => handler.handle_data_hash(hash).await,
           Ok(proto::CreateNewBackupRequest {
             data: Some(NewCompactionChunk(chunk)),
           }) => handler.handle_data_chunk(chunk).await,
           unexpected => {
             error!("Received an unexpected request: {:?}", unexpected);
             Err(Status::unknown("unknown error"))
           }
         };
 
         trace!("Sending response: {:?}", response);
         if let Err(e) = tx.send(response).await {
           error!("Response was dropped: {}", e);
           break;
         }
         if handler.should_close_stream {
           trace!("Handler requested to close stream");
           break;
         }
       }
       if let Err(status) = handler.finish().await {
         trace!("Sending error response: {:?}", status);
         let _ = tx.send(Err(status)).await;
       }
       debug!("Request finished processing");
     };
     tokio::spawn(worker.in_current_span());
 
     let out_stream = ReceiverStream::new(rx);
     Ok(Response::new(
       Box::pin(out_stream) as Self::CreateNewBackupStream
     ))
   }
 
   #[instrument(skip(self))]
   async fn send_log(
     &self,
     _request: Request<tonic::Streaming<proto::SendLogRequest>>,
   ) -> Result<Response<proto::SendLogResponse>, Status> {
     Err(Status::unimplemented("unimplemented"))
   }
 
   type RecoverBackupKeyStream = Pin<
     Box<
       dyn Stream<Item = Result<proto::RecoverBackupKeyResponse, Status>> + Send,
     >,
   >;
 
   #[instrument(skip(self))]
   async fn recover_backup_key(
     &self,
     _request: Request<tonic::Streaming<proto::RecoverBackupKeyRequest>>,
   ) -> Result<Response<Self::RecoverBackupKeyStream>, Status> {
     Err(Status::unimplemented("unimplemented"))
   }
 
   type PullBackupStream = Pin<
     Box<dyn Stream<Item = Result<proto::PullBackupResponse, Status>> + Send>,
   >;
 
   #[instrument(skip(self))]
   async fn pull_backup(
     &self,
     _request: Request<proto::PullBackupRequest>,
   ) -> Result<Response<Self::PullBackupStream>, Status> {
     Err(Status::unimplemented("unimplemented"))
   }
 
-  #[instrument(skip(self))]
+  #[instrument(skip_all,
+    fields(
+      backup_id = &request.get_ref().backup_id,
+      log_id = &request.get_ref().log_id)
+    )]
   async fn add_attachments(
     &self,
-    _request: Request<proto::AddAttachmentsRequest>,
+    request: Request<proto::AddAttachmentsRequest>,
   ) -> Result<Response<()>, Status> {
-    Err(Status::unimplemented("unimplemented"))
+    info!(
+      "AddAttachment request. New holders: {}",
+      &request.get_ref().holders
+    );
+
+    handlers::add_attachments::handle_add_attachments(
+      &self.db,
+      request.into_inner(),
+    )
+    .await?;
+
+    info!("Request processed successfully");
+    Ok(Response::new(()))
   }
 }
 
 /// A helper converting our Database errors into gRPC responses
 fn handle_db_error(db_error: DBError) -> Status {
   match db_error {
     DBError::AwsSdk(DynamoDBError::InternalServerError(_))
     | DBError::AwsSdk(DynamoDBError::ProvisionedThroughputExceededException(
       _,
     ))
     | DBError::AwsSdk(DynamoDBError::RequestLimitExceeded(_)) => {
       warn!("AWS transient error occurred");
       Status::unavailable("please retry")
     }
     e => {
       error!("Encountered an unexpected error: {}", e);
       Status::failed_precondition("unexpected error")
     }
   }
 }