diff --git a/docs/configuration.md b/docs/configuration.md
index 2a95bb1b..1e16b356 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -1456,7 +1456,7 @@ By default, web search uses `duckduckgo`, and it works out of the box without an
 | `olostep` | `apiKey` | `OLOSTEP_API_KEY` | No |
 | `bocha` | `apiKey` | `BOCHA_API_KEY` | Free tier (1M calls for startups) |
 | `volcengine` | `apiKey` | `VOLCENGINE_SEARCH_API_KEY` or `WEB_SEARCH_API_KEY` | Monthly quota, then paid |
-| `keenable` | `apiKey` (optional) | `KEENABLE_API_KEY` | Free tier (no login); key raises rate limits |
+| `keenable` | `apiKey` | `KEENABLE_API_KEY` | No |
 | `searxng` | `baseUrl` | `SEARXNG_BASE_URL` | Yes (self-hosted) |
 | `duckduckgo` (default) | — | — | Yes |
 
@@ -1566,7 +1566,7 @@ You can set `BOCHA_API_KEY` in the environment instead of storing it in config.
 
 You can also set `WEB_SEARCH_API_KEY` for compatibility with the Volcengine web-search skill. Create the key in the [Volcengine web search console](https://console.volcengine.com/search-infinity/web-search), then copy it from [API keys](https://console.volcengine.com/search-infinity/api-key). Volcengine Ark keys are separate and do not work for this search provider.
 
-**Keenable** (free tier, no login required):
+**Keenable:**
 ```json
 {
   "tools": {
@@ -1580,7 +1580,7 @@ You can also set `WEB_SEARCH_API_KEY` for compatibility with the Volcengine web-
 }
 ```
 
-Search works without a key on the free tier; `apiKey` is optional and raises rate limits. Create a key at [keenable.ai](https://keenable.ai). You can also set `KEENABLE_API_KEY` in the environment instead of storing it in config.
+Create a key at [keenable.ai](https://keenable.ai). You can also set `KEENABLE_API_KEY` in the environment instead of storing it in config.
 
 **SearXNG** (self-hosted, no API key needed):
 ```json
diff --git a/nanobot/agent/tools/web.py b/nanobot/agent/tools/web.py
index 78ec89f4..e97f4a65 100644
--- a/nanobot/agent/tools/web.py
+++ b/nanobot/agent/tools/web.py
@@ -318,7 +318,8 @@ class WebSearchTool(Tool):
             )
             return "volcengine" if api_key else "duckduckgo"
         if provider == "keenable":
-            return "keenable"  # free tier works without a key; never fall back
+            api_key = self.config.api_key or os.environ.get("KEENABLE_API_KEY", "")
+            return "keenable" if api_key else "duckduckgo"
         return provider
 
     @property
@@ -490,13 +491,15 @@ class WebSearchTool(Tool):
 
     async def _search_keenable(self, query: str, n: int) -> str:
         api_key = self.config.api_key or os.environ.get("KEENABLE_API_KEY", "")
+        if not api_key:
+            logger.warning("KEENABLE_API_KEY not set, falling back to DuckDuckGo")
+            return await self._search_duckduckgo(query, n)
         headers = {
             "Content-Type": "application/json",
             "User-Agent": self.user_agent,
             "X-Keenable-Title": "nanobot",
+            "X-API-Key": api_key,
         }
-        if api_key:
-            headers["X-API-Key"] = api_key
         try:
             async with httpx.AsyncClient(proxy=self.proxy) as client:
                 r = await client.post(
diff --git a/tests/tools/test_web_search_tool.py b/tests/tools/test_web_search_tool.py
index 4e46f90f..3b380a10 100644
--- a/tests/tools/test_web_search_tool.py
+++ b/tests/tools/test_web_search_tool.py
@@ -131,11 +131,12 @@ async def test_tavily_search(monkeypatch):
     assert "https://openclaw.io" in result
 
 
-def test_keenable_without_api_key_stays_on_provider(monkeypatch):
+def test_keenable_without_api_key_is_treated_as_duckduckgo(monkeypatch):
+    # The REST API requires a key; without one we fall back to DuckDuckGo.
     monkeypatch.delenv("KEENABLE_API_KEY", raising=False)
     tool = _tool(provider="keenable", api_key="")
-    assert tool.exclusive is False
-    assert tool.concurrency_safe is True
+    assert tool.exclusive is True
+    assert tool.concurrency_safe is False
 
 
 @pytest.mark.asyncio
@@ -158,20 +159,20 @@ async def test_keenable_search(monkeypatch):
 
 
 @pytest.mark.asyncio
-async def test_keenable_search_without_key_omits_header(monkeypatch):
+async def test_keenable_fallback_to_duckduckgo_when_no_key(monkeypatch):
+    class MockDDGS:
+        def __init__(self, **kw):
+            pass
+
+        def text(self, query, max_results=5):
+            return [{"title": "Fallback", "href": "https://ddg.example", "body": "DuckDuckGo fallback"}]
+
+    monkeypatch.setattr("ddgs.DDGS", MockDDGS)
     monkeypatch.delenv("KEENABLE_API_KEY", raising=False)
 
-    async def mock_post(self, url, **kw):
-        assert "keenable" in url
-        assert "X-API-Key" not in kw["headers"]
-        return _response(json={
-            "results": [{"title": "Anon", "url": "https://keenable.ai", "description": "ok"}]
-        })
-
-    monkeypatch.setattr(httpx.AsyncClient, "post", mock_post)
     tool = _tool(provider="keenable", api_key="")
     result = await tool.execute(query="keenable", count=1)
-    assert "Anon" in result
+    assert "DuckDuckGo fallback" in result
 
 
 @pytest.mark.asyncio