diff --git a/api/controllers/console/agent/roster.py b/api/controllers/console/agent/roster.py
index d253fb1199d..bd34914909c 100644
--- a/api/controllers/console/agent/roster.py
+++ b/api/controllers/console/agent/roster.py
@@ -66,14 +66,30 @@ class AgentIdPath(BaseModel):
 class AgentAppCreatePayload(BaseModel):
     name: str = Field(..., min_length=1, description="Agent name")
     description: str | None = Field(default=None, description="Agent description (max 400 chars)", max_length=400)
-    role: str = Field(default="", description="Agent role", max_length=255)
+    role: str = Field(..., min_length=1, description="Agent role", max_length=255)
     icon_type: IconType | None = Field(default=None, description="Icon type")
     icon: str | None = Field(default=None, description="Icon")
     icon_background: str | None = Field(default=None, description="Icon background color")
 
+    @field_validator("role")
+    @classmethod
+    def validate_role(cls, value: str) -> str:
+        role = value.strip()
+        if not role:
+            raise ValueError("Agent role is required.")
+        return role
+
 
 class AgentAppUpdatePayload(UpdateAppPayload):
-    role: str | None = Field(default=None, description="Agent role", max_length=255)
+    role: str = Field(..., min_length=1, description="Agent role", max_length=255)
+
+    @field_validator("role")
+    @classmethod
+    def validate_role(cls, value: str) -> str:
+        role = value.strip()
+        if not role:
+            raise ValueError("Agent role is required.")
+        return role
 
 
 class AgentAppPublishedReferenceResponse(BaseModel):
diff --git a/api/openapi/markdown/console-openapi.md b/api/openapi/markdown/console-openapi.md
index fd278d42372..bcbe23d4c3e 100644
--- a/api/openapi/markdown/console-openapi.md
+++ b/api/openapi/markdown/console-openapi.md
@@ -11376,7 +11376,7 @@ Default namespace
 | icon_background | string | Icon background color | No |
 | icon_type | [IconType](#icontype) | Icon type | No |
 | name | string | Agent name | Yes |
-| role | string | Agent role | No |
+| role | string | Agent role | Yes |
 
 #### AgentAppFeaturesPayload
 
@@ -11458,7 +11458,7 @@ default (the config form sends the full desired feature state on save).
 | icon_type | [IconType](#icontype) | Icon type | No |
 | max_active_requests | integer | Maximum active requests | No |
 | name | string | App name | Yes |
-| role | string | Agent role | No |
+| role | string | Agent role | Yes |
 | use_icon_as_answer_icon | boolean | Use icon as answer icon | No |
 
 #### AgentAverageResponseTimeStatisticResponse
diff --git a/api/tests/unit_tests/controllers/console/agent/test_agent_controllers.py b/api/tests/unit_tests/controllers/console/agent/test_agent_controllers.py
index 499fdf54631..e62985d64dc 100644
--- a/api/tests/unit_tests/controllers/console/agent/test_agent_controllers.py
+++ b/api/tests/unit_tests/controllers/console/agent/test_agent_controllers.py
@@ -274,7 +274,13 @@ def test_agent_app_list_and_create_use_agent_route(
 
     with app.test_request_context(
         "/console/api/agent",
-        json={"name": "Iris", "description": "Agent app", "icon_type": "emoji", "icon": "robot"},
+        json={
+            "name": "Iris",
+            "description": "Agent app",
+            "role": "Coordinator",
+            "icon_type": "emoji",
+            "icon": "robot",
+        },
     ):
         created, status = unwrap(AgentAppListApi.post)(AgentAppListApi(), "tenant-1", SimpleNamespace(id=account_id))
 
@@ -287,6 +293,23 @@ def test_agent_app_list_and_create_use_agent_route(
     create_call = cast(dict[str, object], captured["create"])
     create_params = cast(Any, create_call["params"])
     assert create_params.mode == "agent"
+    assert create_params.agent_role == "Coordinator"
+
+
+def test_agent_app_create_requires_role(app: Flask, account_id: str) -> None:
+    with app.test_request_context(
+        "/console/api/agent",
+        json={"name": "Iris", "description": "Agent app", "icon_type": "emoji", "icon": "robot"},
+    ):
+        with pytest.raises(ValueError, match="Field required"):
+            unwrap(AgentAppListApi.post)(AgentAppListApi(), "tenant-1", SimpleNamespace(id=account_id))
+
+    with app.test_request_context(
+        "/console/api/agent",
+        json={"name": "Iris", "description": "Agent app", "role": "   ", "icon_type": "emoji", "icon": "robot"},
+    ):
+        with pytest.raises(ValueError, match="Agent role is required"):
+            unwrap(AgentAppListApi.post)(AgentAppListApi(), "tenant-1", SimpleNamespace(id=account_id))
 
 
 def test_agent_app_detail_update_delete_resolve_app_from_agent_id(
@@ -335,7 +358,7 @@ def test_agent_app_detail_update_delete_resolve_app_from_agent_id(
 
     with app.test_request_context(
         "/console/api/agent/00000000-0000-0000-0000-000000000001",
-        json={"name": "Renamed", "description": "", "icon_type": "emoji", "icon": "R"},
+        json={"name": "Renamed", "description": "", "role": "Reviewer", "icon_type": "emoji", "icon": "R"},
     ):
         updated = unwrap(AgentAppApi.put)(AgentAppApi(), "tenant-1", agent_id)
 
@@ -347,6 +370,7 @@ def test_agent_app_detail_update_delete_resolve_app_from_agent_id(
     assert "bound_agent_id" not in updated
     update_call = cast(dict[str, object], captured["update"])
     assert update_call["app"] is app_model
+    assert cast(dict[str, object], update_call["args"])["role"] == "Reviewer"
 
     deleted, status = unwrap(AgentAppApi.delete)(AgentAppApi(), "tenant-1", agent_id)
     assert (deleted, status) == ("", 204)
@@ -399,6 +423,45 @@ def test_agent_app_copy_uses_agent_id_and_returns_agent_detail(
     }
 
 
+def test_agent_app_update_rejects_empty_role(app: Flask, monkeypatch: pytest.MonkeyPatch) -> None:
+    agent_id = "00000000-0000-0000-0000-000000000001"
+    app_model = _app_detail_obj(id="app-1", bound_agent_id=agent_id)
+    captured: dict[str, object] = {}
+
+    monkeypatch.setattr(
+        roster_controller.AgentRosterService,
+        "get_agent_app_model",
+        lambda _self, **kwargs: app_model,
+    )
+    monkeypatch.setattr(
+        roster_controller.AgentRosterService,
+        "get_app_backing_agent",
+        lambda _self, **kwargs: SimpleNamespace(id=agent_id, role="", active_config_snapshot_id=None),
+    )
+    monkeypatch.setattr(
+        roster_controller.FeatureService,
+        "get_system_features",
+        lambda: SimpleNamespace(webapp_auth=SimpleNamespace(enabled=False)),
+    )
+
+    class FakeAppService:
+        def get_app(self, app_obj: object) -> object:
+            return app_obj
+
+        def update_app(self, app_obj: object, args: dict[str, object]) -> object:
+            captured["update"] = {"app": app_obj, "args": args}
+            return _app_detail_obj(id="app-1", name=args["name"], bound_agent_id=agent_id)
+
+    monkeypatch.setattr(roster_controller, "AppService", FakeAppService)
+
+    with app.test_request_context(
+        "/console/api/agent/00000000-0000-0000-0000-000000000001",
+        json={"name": "Renamed", "description": "", "role": "", "icon_type": "emoji", "icon": "R"},
+    ):
+        with pytest.raises(ValueError, match="String should have at least 1 character"):
+            unwrap(AgentAppApi.put)(AgentAppApi(), "tenant-1", agent_id)
+
+
 def test_invite_options_get_parses_app_id(app: Flask, monkeypatch: pytest.MonkeyPatch) -> None:
     captured: dict[str, object] = {}
 
diff --git a/packages/contracts/generated/api/console/agent/types.gen.ts b/packages/contracts/generated/api/console/agent/types.gen.ts
index 9daae340350..46cb0545405 100644
--- a/packages/contracts/generated/api/console/agent/types.gen.ts
+++ b/packages/contracts/generated/api/console/agent/types.gen.ts
@@ -18,7 +18,7 @@ export type AgentAppCreatePayload = {
   icon_background?: string | null
   icon_type?: IconType | null
   name: string
-  role?: string
+  role: string
 }
 
 export type AppDetailWithSite = {
@@ -67,7 +67,7 @@ export type AgentAppUpdatePayload = {
   icon_type?: IconType | null
   max_active_requests?: number | null
   name: string
-  role?: string | null
+  role: string
   use_icon_as_answer_icon?: boolean | null
 }
 
diff --git a/packages/contracts/generated/api/console/agent/zod.gen.ts b/packages/contracts/generated/api/console/agent/zod.gen.ts
index 07e753e0c9b..6811b8a80bb 100644
--- a/packages/contracts/generated/api/console/agent/zod.gen.ts
+++ b/packages/contracts/generated/api/console/agent/zod.gen.ts
@@ -92,7 +92,7 @@ export const zAgentAppCreatePayload = z.object({
   icon_background: z.string().nullish(),
   icon_type: zIconType.nullish(),
   name: z.string().min(1),
-  role: z.string().max(255).optional().default(''),
+  role: z.string().min(1).max(255),
 })
 
 /**
@@ -105,7 +105,7 @@ export const zAgentAppUpdatePayload = z.object({
   icon_type: zIconType.nullish(),
   max_active_requests: z.int().nullish(),
   name: z.string().min(1),
-  role: z.string().max(255).nullish(),
+  role: z.string().min(1).max(255),
   use_icon_as_answer_icon: z.boolean().nullish(),
 })