diff --git a/api/apps/restful_apis/bot_api.py b/api/apps/restful_apis/bot_api.py
index 8c0e6e7467..efc1836ab5 100644
--- a/api/apps/restful_apis/bot_api.py
+++ b/api/apps/restful_apis/bot_api.py
@@ -161,6 +161,14 @@ async def chatbots_inputs(dialog_id, tenant_id=None):
 async def agent_bot_completions(agent_id, tenant_id=None):
     req = await get_request_json()
 
+    if not await thread_pool_exec(UserCanvasService.accessible, agent_id, tenant_id):
+        logger.warning(
+            "agent_bot_completions access denied tenant_id=%s agent_id=%s",
+            tenant_id,
+            agent_id,
+        )
+        return get_error_data_result(message=f"Can't find agent by ID: {agent_id}")
+
     if req.get("stream", True):
         async def stream():
             try:
@@ -241,6 +249,14 @@ async def agent_bot_completions(agent_id, tenant_id=None):
 @login_required(auth_types=AUTH_BETA)
 @add_tenant_id_to_kwargs
 async def begin_inputs(agent_id, tenant_id=None):
+    if not await thread_pool_exec(UserCanvasService.accessible, agent_id, tenant_id):
+        logger.warning(
+            "begin_inputs access denied tenant_id=%s agent_id=%s",
+            tenant_id,
+            agent_id,
+        )
+        return get_error_data_result(f"Can't find agent by ID: {agent_id}")
+
     e, cvs = await thread_pool_exec(UserCanvasService.get_by_id, agent_id)
     if not e:
         return get_error_data_result(f"Can't find agent by ID: {agent_id}")
diff --git a/test/unit_test/api/apps/restful_apis/test_agentbots_access_control.py b/test/unit_test/api/apps/restful_apis/test_agentbots_access_control.py
new file mode 100644
index 0000000000..a778147cb9
--- /dev/null
+++ b/test/unit_test/api/apps/restful_apis/test_agentbots_access_control.py
@@ -0,0 +1,168 @@
+#
+#  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+"""Regression tests for cross-tenant access control on the SDK agent-bot routes
+(`api/apps/restful_apis/bot_api.py`).
+
+`POST /agentbots/<agent_id>/completions` and `GET /agentbots/<agent_id>/inputs`
+authenticate with a beta API token (which only yields the caller's tenant_id)
+and then load/run the agent named in the URL. They must reject an `agent_id`
+the caller's tenant cannot access (`UserCanvasService.accessible`) instead of
+loading or executing another tenant's agent.
+"""
+
+import asyncio
+import importlib.util
+import sys
+from pathlib import Path
+from types import ModuleType, SimpleNamespace
+
+import pytest
+
+
+class _PassthroughManager:
+    def route(self, *_args, **_kwargs):
+        return lambda func: func
+
+
+def _stub(monkeypatch, name, **attrs):
+    mod = ModuleType(name)
+    for key, value in attrs.items():
+        setattr(mod, key, value)
+    monkeypatch.setitem(sys.modules, name, mod)
+    return mod
+
+
+async def _passthrough_thread_pool_exec(fn, *args, **kwargs):
+    return fn(*args, **kwargs)
+
+
+def _load_bot_api(monkeypatch, *, accessible, calls):
+    """Load bot_api.py with the minimum stubs required.
+
+    `accessible` is what the stubbed `UserCanvasService.accessible` returns.
+    `calls` is a dict used to record whether the agent-loading paths were hit.
+    """
+    user_canvas_service = SimpleNamespace(
+        accessible=lambda *_a, **_k: accessible,
+        get_by_id=lambda agent_id: (calls.__setitem__("get_by_id", agent_id), (True, SimpleNamespace(dsl="{}", id=agent_id, title="t", avatar="a")))[1],
+        query=lambda **_kwargs: [],
+    )
+
+    def _completion(*_a, **_k):
+        calls["completion"] = True
+
+        async def _gen():
+            if False:
+                yield ""
+        return _gen()
+
+    _stub(monkeypatch, "quart", Response=lambda *a, **k: SimpleNamespace(headers=SimpleNamespace(add_header=lambda *aa, **kk: None)), request=SimpleNamespace())
+    _stub(monkeypatch, "api.apps", AUTH_BETA="beta", login_required=lambda *_a, **_k: (lambda func: func))
+    _stub(monkeypatch, "agent.canvas", Canvas=lambda *a, **k: SimpleNamespace(get_component_input_form=lambda _n: {}, get_prologue=lambda: "", get_mode=lambda: "agent"))
+    _stub(monkeypatch, "api.db.db_models", APIToken=SimpleNamespace(query=lambda **_k: [SimpleNamespace(tenant_id="attacker-tenant")]))
+    _stub(monkeypatch, "api.db.services.api_service", API4ConversationService=SimpleNamespace())
+    _stub(monkeypatch, "api.db.services.canvas_service", UserCanvasService=user_canvas_service, completion=_completion)
+    _stub(monkeypatch, "api.db.services.user_canvas_version", UserCanvasVersionService=SimpleNamespace())
+    _stub(monkeypatch, "api.db.services.conversation_service", async_iframe_completion=lambda *_a, **_k: None)
+    _stub(monkeypatch, "api.db.services.dialog_service", DialogService=SimpleNamespace(), async_ask=lambda *_a, **_k: None, gen_mindmap=lambda *_a, **_k: None)
+    _stub(monkeypatch, "api.db.services.doc_metadata_service", DocMetadataService=SimpleNamespace())
+    _stub(monkeypatch, "api.db.services.knowledgebase_service", KnowledgebaseService=SimpleNamespace())
+    _stub(monkeypatch, "api.db.services.llm_service", LLMBundle=SimpleNamespace())
+    _stub(monkeypatch, "common.metadata_utils", apply_meta_data_filter=lambda *_a, **_k: None)
+    _stub(monkeypatch, "api.db.services.search_service", SearchService=SimpleNamespace())
+    _stub(monkeypatch, "api.db.services.user_service", UserTenantService=SimpleNamespace())
+    _stub(monkeypatch, "api.db.joint_services.tenant_model_service", get_tenant_default_model_by_type=lambda *_a, **_k: None, get_model_config_from_provider_instance=lambda *_a, **_k: None)
+    _stub(monkeypatch, "common.misc_utils", get_uuid=lambda: "uuid", thread_pool_exec=_passthrough_thread_pool_exec)
+    _stub(
+        monkeypatch,
+        "api.utils.api_utils",
+        add_tenant_id_to_kwargs=lambda func: func,
+        check_duplicate_ids=lambda *_a, **_k: None,
+        get_error_data_result=lambda message="Sorry", **_k: {"code": 102, "message": message, "data": None},
+        get_json_result=lambda code=0, message="", data=None: {"code": code, "message": message, "data": data},
+        get_result=lambda **kwargs: {"code": 0, "data": kwargs.get("data")},
+        get_request_json=_async_empty_json,
+        server_error_response=lambda exc: {"code": 500, "message": str(exc)},
+        token_required=lambda func: func,
+        validate_request=lambda *_a, **_k: lambda func: func,
+    )
+    _stub(monkeypatch, "rag.app.tag", label_question=lambda *_a, **_k: None)
+    _stub(monkeypatch, "rag.prompts.template", load_prompt=lambda *_a, **_k: "")
+    _stub(monkeypatch, "rag.prompts.generator", cross_languages=lambda *_a, **_k: None, keyword_extraction=lambda *_a, **_k: None)
+    _stub(monkeypatch, "common.constants", RetCode=SimpleNamespace(), LLMType=SimpleNamespace(), StatusEnum=SimpleNamespace())
+    _stub(monkeypatch, "common", settings=SimpleNamespace())
+    _stub(monkeypatch, "common.settings", retriever=SimpleNamespace(), kg_retriever=SimpleNamespace())
+    _stub(monkeypatch, "api.utils.reference_metadata_utils", enrich_chunks_with_document_metadata=lambda *_a, **_k: None, resolve_reference_metadata_preferences=lambda *_a, **_k: None)
+
+    repo_root = Path(__file__).resolve().parents[5]
+    module_path = repo_root / "api" / "apps" / "restful_apis" / "bot_api.py"
+    spec = importlib.util.spec_from_file_location("test_agentbots_bot_api", module_path)
+    module = importlib.util.module_from_spec(spec)
+    module.manager = _PassthroughManager()
+    monkeypatch.setitem(sys.modules, "test_agentbots_bot_api", module)
+    spec.loader.exec_module(module)
+    return module
+
+
+async def _async_empty_json():
+    return {}
+
+
+@pytest.mark.p1
+class TestAgentBotAccessControl:
+    """Regression: agentbots completions/inputs must enforce tenant ownership."""
+
+    @pytest.mark.p1
+    def test_begin_inputs_denied_for_inaccessible_agent(self, monkeypatch):
+        calls = {}
+        module = _load_bot_api(monkeypatch, accessible=False, calls=calls)
+
+        result = asyncio.run(module.begin_inputs(agent_id="victim-agent"))
+
+        assert result == {"code": 102, "message": "Can't find agent by ID: victim-agent", "data": None}
+        # Must short-circuit before ever loading the foreign agent.
+        assert "get_by_id" not in calls
+
+    @pytest.mark.p1
+    def test_completions_denied_for_inaccessible_agent(self, monkeypatch):
+        calls = {}
+        module = _load_bot_api(monkeypatch, accessible=False, calls=calls)
+
+        result = asyncio.run(module.agent_bot_completions(agent_id="victim-agent"))
+
+        assert result == {"code": 102, "message": "Can't find agent by ID: victim-agent", "data": None}
+        # Must short-circuit before ever running the foreign agent.
+        assert "completion" not in calls
+
+    @pytest.mark.p1
+    def test_begin_inputs_allowed_for_accessible_agent(self, monkeypatch):
+        calls = {}
+        module = _load_bot_api(monkeypatch, accessible=True, calls=calls)
+
+        result = asyncio.run(module.begin_inputs(agent_id="own-agent"))
+
+        assert calls.get("get_by_id") == "own-agent"
+        assert result["code"] == 0
+
+    @pytest.mark.p1
+    def test_completions_allowed_for_accessible_agent(self, monkeypatch):
+        calls = {}
+        module = _load_bot_api(monkeypatch, accessible=True, calls=calls)
+
+        result = asyncio.run(module.agent_bot_completions(agent_id="own-agent"))
+
+        assert calls.get("completion") is True
+        assert result["code"] == 0