diff --git a/server/controllers/shelf.js b/server/controllers/shelf.js
index 51a958e..1505db2 100644
--- a/server/controllers/shelf.js
+++ b/server/controllers/shelf.js
@@ -248,6 +248,32 @@ class ShelfController {
 
     return shelfData;
   }
+
+  async addShelfItem(shelf, bookReferenceId, source = null) {
+    const bookReferenceController = new BookReferenceController(this.models, this.lang);
+    
+    let bookId = bookReferenceId;
+    if (source !== null) {
+      const bookReference = await bookReferenceController.createOrUpdateReference(source, bookId);
+      bookId = bookReference.id;
+    }
+
+    if (shelf.ShelfItems.some(shelfItem => shelfItem.bookId === bookId)) {
+      return {
+        error: 'api.shelf.addItem.already_on_shelf',  // This may need to change to account for editions later.
+      }
+    }
+
+    const shelfItem = await shelf.addShelfItem({ bookId }).catch(err => err);
+
+    if (!shelfItem) {
+      return {
+        error: shelfItem,
+      };
+    }
+
+    return shelfItem;
+  }
 }
 
 module.exports = ShelfController;
\ No newline at end of file
diff --git a/server/routes/shelf.js b/server/routes/shelf.js
index 339f6f7..a53c099 100644
--- a/server/routes/shelf.js
+++ b/server/routes/shelf.js
@@ -165,6 +165,57 @@ async function routes(fastify, options) {
       message: 'api.shelf.rename.success',
     });
   });
+
+  fastify.post('/api/shelf/addItem', async (request, reply) => {
+    if (!request.isLoggedInUser) {
+      return reply.code(401).send({
+        error: true,
+        message: 'api.not_logged_in',
+      });
+    }
+
+    if (typeof request.body.shelfId === 'undefined') {
+      return reply.code(400).send({
+        error: true,
+        message: 'api.shelf.addItem.missing_id',
+      });
+    }
+
+    if (typeof request.body.bookId === 'undefined') {
+      return reply.code(400).send({
+        error: true,
+        message: 'api.shelf.addItem.missing_id',
+      });
+    }
+
+    const shelf = await request.user.getShelf({
+      where: { id: request.body.shelfId },
+      include: [ fastify.models.ShelfItem ],
+    });
+
+    if (!ShelfController.userOwnsShelf(request.user, shelf)) {
+      return reply.code(403).send({
+        error: true,
+        message: 'api.shelf.not_owner',
+      });
+    }
+
+    const shelfController = new ShelfController(fastify.models, request.language);
+    
+    const shelfItem = await shelfController.addShelfItem(shelf, request.body.bookId, request.body.source);
+
+    if (typeof shelfItem.error !== 'undefined') {
+      return reply.code(400).send({
+        error: shelfItem.error,
+        message: 'api.shelf.addItem.could_not_add',
+      });
+    }
+
+    return reply.send({
+      error: false,
+      message: 'api.shelf.addItem.success',
+    });
+  });
 }
 
 module.exports = routes;
\ No newline at end of file