diff --git a/example/vikunja/go.mod b/example/vikunja/go.mod
index e18d757..2ba8ae8 100644
--- a/example/vikunja/go.mod
+++ b/example/vikunja/go.mod
@@ -8,4 +8,8 @@ require gitcode.com/JianFeeeee/homeagent-sdk v1.2.0
 
 
 
+
+
+
+
 replace gitcode.com/JianFeeeee/homeagent-sdk => /root/.homeagent/hmapdev/sdk/v1.2.0
diff --git a/example/vikunja/plg.json b/example/vikunja/plg.json
index beebe1e..c3ac6dc 100644
--- a/example/vikunja/plg.json
+++ b/example/vikunja/plg.json
@@ -2,7 +2,7 @@
   "name": "vikunja",
   "name_zh": "Vikunja 待办",
   "name_en": "Vikunja",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "Vikunja 待办/任务管理：任务增删改查、项目与看板桶、标签、指派、评论、关联、附件、保存筛选器、团队与分享、通知、订阅、Webhook、时间跟踪、数据导入、实例管理；并附通用 API 直通工具兜底",
   "author": "HomeAgent",
   "entry": "plugin.bin",
diff --git a/example/vikunja/plugin.go b/example/vikunja/plugin.go
index 56859e0..7f20901 100644
--- a/example/vikunja/plugin.go
+++ b/example/vikunja/plugin.go
@@ -1152,7 +1152,9 @@ func taskBody(args map[string]interface{}, includeTitle bool) map[string]interfa
 		}
 	}
 	if v := argID(args, "project_id"); v != "" {
-		body["project_id"] = v
+		// 必须是 JSON 数字：发字符串 "1" 会被 Vikunja 判 422 expected integer
+		// （v2 body.project_id 校验 integer；线上实测）
+		body["project_id"] = parseID(v)
 	}
 	return body
 }
@@ -1214,7 +1216,12 @@ func (p *Plugin) handleTaskCreate(args map[string]interface{}) (interface{}, err
 		}
 		if asg := argStr(args, "assignees"); asg != "" {
 			for _, u := range splitCSV(asg) {
-				if _, err := p.call(p.addAssigneeMethod(), "/tasks/"+taskID+"/assignees", map[string]interface{}{"user_id": u, "username": u}); err != nil {
+				body, berr := p.assigneeBody(u)
+				if berr != nil {
+					notes = append(notes, "指派 "+u+" 失败: "+berr.Error())
+					continue
+				}
+				if _, err := p.call(p.addAssigneeMethod(), "/tasks/"+taskID+"/assignees", body); err != nil {
 					notes = append(notes, "指派 "+u+" 失败: "+err.Error())
 				}
 			}
@@ -1403,17 +1410,21 @@ func (p *Plugin) handleTaskAssignees(args map[string]interface{}) (interface{},
 		if user == "" {
 			return nil, errors.New("add 需要参数 user（用户名或用户 ID）")
 		}
-		body := map[string]interface{}{"username": user}
-		if n, err := strconv.Atoi(user); err == nil {
-			body["user_id"] = n
+		body, err := p.assigneeBody(user)
+		if err != nil {
+			return nil, err
 		}
 		return p.call(p.addAssigneeMethod(), "/tasks/"+id+"/assignees", body)
 	case "remove":
 		user := argStr(args, "user")
 		if user == "" {
-			return nil, errors.New("remove 需要参数 user（用户 ID）")
+			return nil, errors.New("remove 需要参数 user（用户名或用户 ID）")
 		}
-		return p.call(http.MethodDelete, "/tasks/"+id+"/assignees/"+user, nil)
+		uid, err := p.resolveUserID(user)
+		if err != nil {
+			return nil, err
+		}
+		return p.call(http.MethodDelete, "/tasks/"+id+"/assignees/"+strconv.Itoa(uid), nil)
 	}
 	return nil, fmt.Errorf("未知 action: %s（可用 list|add|remove）", action)
 }
@@ -1531,6 +1542,78 @@ func parseID(s string) interface{} {
 	return s
 }
 
+// numOf 把 JSON 解出的值取成整数（SDK 放进 map 的数字是 float64）
+func numOf(v interface{}) int {
+	switch n := v.(type) {
+	case float64:
+		return int(n)
+	case int:
+		return n
+	case int64:
+		return int(n)
+	case json.Number:
+		if i, err := n.Int64(); err == nil {
+			return int(i)
+		}
+	case string:
+		if i, err := strconv.Atoi(strings.TrimSpace(n)); err == nil {
+			return i
+		}
+	}
+	return 0
+}
+
+// resolveUserID 把「用户名或 ID」解析成**数字** user_id。
+//
+// 为什么必须解析：v2 的 assignees 只接受 {"user_id":N}
+//   - 发 {"username":"x"} → 422 unexpected property
+//   - 发 {"user_id":"1"}  → 422 expected integer
+//
+// 两种都已在线上实测确认（2026-09-12）。
+func (p *Plugin) resolveUserID(user string) (int, error) {
+	u := strings.TrimSpace(user)
+	if u == "" {
+		return 0, errors.New("需要参数 user（用户名或用户 ID）")
+	}
+	if n, err := strconv.Atoi(u); err == nil {
+		return n, nil
+	}
+	res, err := p.call(http.MethodGet, qv("/users", p.searchParam(), u), nil)
+	if err != nil {
+		return 0, fmt.Errorf("按用户名 %q 查用户失败: %w", u, err)
+	}
+	items := asSlice(res)
+	var names []string
+	for _, it := range items {
+		m, ok := it.(map[string]interface{})
+		if !ok {
+			continue
+		}
+		name := fmt.Sprint(m["username"])
+		names = append(names, name)
+		if strings.EqualFold(name, u) {
+			if id := numOf(m["id"]); id > 0 {
+				return id, nil
+			}
+		}
+	}
+	// 只认精确匹配（不区分大小写）。不做「只有一条就用它」的模糊兜底：
+	// 指派会写到别人的任务上，猜错人比让模型改用数字 ID 更贵。
+	if len(names) > 0 {
+		return 0, fmt.Errorf("找不到用户 %q（同名/相近的：%s）；也可直接传数字用户 ID", u, strings.Join(names, ", "))
+	}
+	return 0, fmt.Errorf("找不到用户 %q", u)
+}
+
+// assigneeBody 拼出指派请求体：只含数字 user_id（见 resolveUserID 的说明）
+func (p *Plugin) assigneeBody(user string) (map[string]interface{}, error) {
+	uid, err := p.resolveUserID(user)
+	if err != nil {
+		return nil, err
+	}
+	return map[string]interface{}{"user_id": uid}, nil
+}
+
 func (p *Plugin) handleTaskAttachments(args map[string]interface{}) (interface{}, error) {
 	p.ensure()
 	id := argID(args, "id")
diff --git a/example/vikunja/plugin_test.go b/example/vikunja/plugin_test.go
index 0707f22..f50e533 100644
--- a/example/vikunja/plugin_test.go
+++ b/example/vikunja/plugin_test.go
@@ -401,3 +401,123 @@ func TestCompactToggle(t *testing.T) {
 		t.Errorf("关闭精简后应保留 description")
 	}
 }
+
+// ── 回归：JSON body 里的 ID 必须是数字（线上实测的 422 缺口）────────────
+//
+// vikunja v2.6.0 实测（2026-09-12）：
+//   {"project_id":"1"}   → 422 expected integer at body.project_id
+//   {"user_id":"1"}      → 422 expected integer at body.user_id
+//   {"username":"jianf"} → 422 unexpected property at body.username
+// 旧实现把 argID() 的字符串直接塞进 body，assignee 还额外带 username，
+// 于是「建任务」「指派」在 v2 下必定失败 —— 只有真调用才暴露，单测没盖到。
+
+func TestTaskCreateSendsNumericProjectID(t *testing.T) {
+	var body map[string]interface{}
+	var raw []byte
+	p, _ := newTestPlugin(t, func(w http.ResponseWriter, r *http.Request) {
+		raw, _ = io.ReadAll(r.Body)
+		_ = json.Unmarshal(raw, &body)
+		_, _ = w.Write([]byte(`{"id":42,"title":"买菜"}`))
+	})
+	// project_id 传 float64 —— 这正是 SDK 从 JSON 解出来的真实类型
+	if _, err := p.handleTaskCreate(map[string]interface{}{"project_id": float64(3), "title": "买菜"}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if _, ok := body["project_id"].(float64); !ok {
+		t.Errorf("project_id 必须是 JSON 数字，实际 %T=%v", body["project_id"], body["project_id"])
+	}
+	if strings.Contains(string(raw), `"project_id":"`) {
+		t.Errorf("出现字符串型 project_id（v2 会 422 expected integer）: %s", raw)
+	}
+}
+
+func TestAssigneeAddResolvesUsernameToNumericUserID(t *testing.T) {
+	var body map[string]interface{}
+	var raw []byte
+	var calls []string
+	p, _ := newTestPlugin(t, func(w http.ResponseWriter, r *http.Request) {
+		calls = append(calls, r.Method+" "+r.URL.Path)
+		switch r.URL.Path {
+		case "/api/v2/users":
+			if r.URL.Query().Get("q") != "alice" {
+				t.Errorf("v2 用户搜索应用 q=，实际 query=%q", r.URL.RawQuery)
+			}
+			_, _ = w.Write([]byte(`[{"id":7,"username":"alice"},{"id":9,"username":"alice2"}]`))
+		case "/api/v2/tasks/1/assignees":
+			raw, _ = io.ReadAll(r.Body)
+			_ = json.Unmarshal(raw, &body)
+			w.WriteHeader(http.StatusCreated)
+			_, _ = w.Write([]byte(`{"user_id":7}`))
+		default:
+			t.Errorf("意外请求: %s %s", r.Method, r.URL.Path)
+		}
+	})
+	if _, err := p.handleTaskAssignees(map[string]interface{}{"id": "1", "action": "add", "user": "alice"}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if len(calls) != 2 {
+		t.Fatalf("应先查用户再指派，实际调用: %v", calls)
+	}
+	if n, ok := body["user_id"].(float64); !ok || int(n) != 7 {
+		t.Errorf("user_id 必须是数字 7，实际 %T=%v", body["user_id"], body["user_id"])
+	}
+	if _, ok := body["username"]; ok {
+		t.Errorf("v2 不接受 username 字段（422 unexpected property）: %s", raw)
+	}
+}
+
+func TestAssigneeAddNumericUserSkipsLookup(t *testing.T) {
+	var calls []string
+	var body map[string]interface{}
+	p, _ := newTestPlugin(t, func(w http.ResponseWriter, r *http.Request) {
+		calls = append(calls, r.Method+" "+r.URL.Path)
+		if r.URL.Path == "/api/v2/users" {
+			t.Errorf("传数字 ID 时不该再查用户表")
+		}
+		raw, _ := io.ReadAll(r.Body)
+		_ = json.Unmarshal(raw, &body)
+		w.WriteHeader(http.StatusCreated)
+		_, _ = w.Write([]byte(`{"user_id":7}`))
+	})
+	if _, err := p.handleTaskAssignees(map[string]interface{}{"id": "1", "action": "add", "user": "7"}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if len(calls) != 1 {
+		t.Errorf("应只有一次请求，实际: %v", calls)
+	}
+	if n, ok := body["user_id"].(float64); !ok || int(n) != 7 {
+		t.Errorf("user_id 应为数字 7，实际 %T=%v", body["user_id"], body["user_id"])
+	}
+}
+
+func TestAssigneeRemoveUsesResolvedNumericPath(t *testing.T) {
+	var gotPath string
+	p, _ := newTestPlugin(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/api/v2/users":
+			_, _ = w.Write([]byte(`[{"id":7,"username":"alice"}]`))
+		default:
+			gotPath = r.Method + " " + r.URL.Path
+			w.WriteHeader(http.StatusNoContent)
+		}
+	})
+	if _, err := p.handleTaskAssignees(map[string]interface{}{"id": "1", "action": "remove", "user": "alice"}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if gotPath != "DELETE /api/v2/tasks/1/assignees/7" {
+		t.Errorf("移除应用解析出的数字 ID，实际 %q", gotPath)
+	}
+}
+
+func TestAssigneeAddUnknownUserGivesReadableError(t *testing.T) {
+	p, _ := newTestPlugin(t, func(w http.ResponseWriter, r *http.Request) {
+		_, _ = w.Write([]byte(`[{"id":7,"username":"bob"}]`))
+	})
+	_, err := p.handleTaskAssignees(map[string]interface{}{"id": "1", "action": "add", "user": "alice"})
+	if err == nil {
+		t.Fatal("找不到用户时必须报错，而不是发出一个注定 422 的请求")
+	}
+	if !strings.Contains(err.Error(), "找不到用户") || !strings.Contains(err.Error(), "bob") {
+		t.Errorf("错误信息应说明找不到并给出相近候选: %v", err)
+	}
+}