diff --git a/src/api.ts b/src/api.ts
index 05736c4..2e4e8ce 100644
--- a/src/api.ts
+++ b/src/api.ts
@@ -1,6 +1,6 @@
 import axios from "axios"
 import { router } from "./router"
-import type { TutorialIn, ChallengeIn } from "./utils/type"
+import type { TutorialIn, ChallengeIn, FlagType } from "./utils/type"
 import { BASE_URL, STORAGE_KEY } from "./utils/const"
 
 const http = axios.create({
@@ -167,6 +167,11 @@ export const Submission = {
     const res = await http.put(`/submission/${id}/score`, { score })
     return res.data
   },
+
+  async updateFlag(id: string, flag: FlagType) {
+    const res = await http.put(`/submission/${id}/flag`, { flag })
+    return res.data
+  },
 }
 
 export const Prompt = {
diff --git a/src/utils/type.ts b/src/utils/type.ts
index beae1bc..b3f15a6 100644
--- a/src/utils/type.ts
+++ b/src/utils/type.ts
@@ -14,6 +14,8 @@ export function getRole(role: Role) {
   }[role]
 }
 
+export type FlagType = "red" | "blue" | "green" | "yellow" | null
+
 export interface TutorialSlim {
   display: number
   title: string
@@ -64,6 +66,7 @@ export interface SubmissionOut {
   score: number
   my_score: number
   conversation_id?: string
+  flag?: FlagType
   created: Date
   modified: Date
 }
@@ -78,6 +81,7 @@ export interface SubmissionAll {
   task_title: string
   score: number
   my_score: number
+  flag?: FlagType
   html: ""
   css: ""
   js: ""