diff --git a/src/controllers/api/setEquippedInstrumentController.ts b/src/controllers/api/setEquippedInstrumentController.ts
new file mode 100644
index 000000000..0781825ab
--- /dev/null
+++ b/src/controllers/api/setEquippedInstrumentController.ts
@@ -0,0 +1,17 @@
+import { RequestHandler } from "express";
+import { getAccountIdForRequest } from "@/src/services/loginService";
+import { getInventory } from "@/src/services/inventoryService";
+import { getJSONfromString } from "@/src/helpers/stringHelpers";
+
+export const setEquippedInstrumentController: RequestHandler = async (req, res) => {
+    const accountId = await getAccountIdForRequest(req);
+    const inventory = await getInventory(accountId);
+    const body = getJSONfromString(String(req.body)) as ISetEquippedInstrumentRequest;
+    inventory.EquippedInstrument = body.Instrument;
+    await inventory.save();
+    res.end();
+};
+
+interface ISetEquippedInstrumentRequest {
+    Instrument: string;
+}
diff --git a/src/routes/api.ts b/src/routes/api.ts
index 2cc428a73..b6e2613ce 100644
--- a/src/routes/api.ts
+++ b/src/routes/api.ts
@@ -56,6 +56,7 @@ import { sellController } from "@/src/controllers/api/sellController";
 import { setActiveQuestController } from "@/src/controllers/api/setActiveQuestController";
 import { setActiveShipController } from "@/src/controllers/api/setActiveShipController";
 import { setBootLocationController } from "@/src/controllers/api/setBootLocationController";
+import { setEquippedInstrumentController } from "@/src/controllers/api/setEquippedInstrumentController";
 import { setPlacedDecoInfoController } from "@/src/controllers/api/setPlacedDecoInfoController";
 import { setShipCustomizationsController } from "@/src/controllers/api/setShipCustomizationsController";
 import { setShipFavouriteLoadoutController } from "@/src/controllers/api/setShipFavouriteLoadoutController";
@@ -141,6 +142,7 @@ apiRouter.post("/purchase.php", purchaseController);
 apiRouter.post("/rerollRandomMod.php", rerollRandomModController);
 apiRouter.post("/saveLoadout.php", saveLoadoutController);
 apiRouter.post("/sell.php", sellController);
+apiRouter.post("/setEquippedInstrument.php", setEquippedInstrumentController);
 apiRouter.post("/setPlacedDecoInfo.php", setPlacedDecoInfoController);
 apiRouter.post("/setShipCustomizations.php", setShipCustomizationsController);
 apiRouter.post("/setShipFavouriteLoadout.php", setShipFavouriteLoadoutController);
diff --git a/src/types/inventoryTypes/inventoryTypes.ts b/src/types/inventoryTypes/inventoryTypes.ts
index 89088da2f..dc9e6ef34 100644
--- a/src/types/inventoryTypes/inventoryTypes.ts
+++ b/src/types/inventoryTypes/inventoryTypes.ts
@@ -250,7 +250,7 @@ export interface IInventoryResponse {
     CompletedJobChains: ICompletedJobChain[];
     SeasonChallengeHistory: ISeasonChallenge[];
     MoaPets: IEquipmentDatabase[];
-    EquippedInstrument: string;
+    EquippedInstrument?: string;
     InvasionChainProgress: IInvasionChainProgress[];
     DataKnives: IEquipmentDatabase[];
     Motorcycles: IEquipmentDatabase[];