fix(web): back off Brave search rate limits

nanobot/agent/tools/web.py

@@ -272,23 +272,37 @@ class WebSearchTool(Tool):
             logger.warning("BRAVE_API_KEY not set, falling back to DuckDuckGo")
             return await self._search_duckduckgo(query, n)
         try:
+            headers = {
+                "Accept": "application/json",
+                "X-Subscription-Token": api_key,
+                "User-Agent": self.user_agent,
+            }
             async with httpx.AsyncClient(proxy=self.proxy) as client:
-                r = await client.get(
-                    "https://api.search.brave.com/res/v1/web/search",
-                    params={"q": query, "count": n},
-                    headers={
-                        "Accept": "application/json",
-                        "X-Subscription-Token": api_key,
-                        "User-Agent": self.user_agent,
-                    },
-                    timeout=10.0,
-                )
+                for attempt in range(2):
+                    r = await client.get(
+                        "https://api.search.brave.com/res/v1/web/search",
+                        params={"q": query, "count": n},
+                        headers=headers,
+                        timeout=10.0,
+                    )
+                    if r.status_code != 429:
+                        break
+                    if attempt == 0:
+                        logger.warning("Brave search rate limited; retrying once in 1.0s")
+                        await asyncio.sleep(1.0)
                 r.raise_for_status()
             items = [
                 {"title": x.get("title", ""), "url": x.get("url", ""), "content": x.get("description", "")}
                 for x in r.json().get("web", {}).get("results", [])
             ]
             return _format_results(query, items, n)
+        except httpx.HTTPStatusError as e:
+            if e.response.status_code == 429:
+                return (
+                    "Error: Brave search rate limited after retry. "
+                    "Retry later or reduce consecutive web_search calls."
+                )
+            return f"Error: {e}"
         except Exception as e:
             return f"Error: {e}"
 

tests/tools/test_web_search_tool.py

@@ -19,7 +19,10 @@ def _tool(
     )
 
 
-def _response(status: int = 200, json: dict | None = None) -> httpx.Response:
+def _response(
+    status: int = 200,
+    json: dict | None = None,
+) -> httpx.Response:
     """Build a mock httpx.Response with a dummy request attached."""
     r = httpx.Response(status, json=json)
     r._request = httpx.Request("GET", "https://mock")
@@ -62,6 +65,55 @@ async def test_brave_search(monkeypatch):
     assert "https://example.com" in result
 
 
+@pytest.mark.asyncio
+async def test_brave_search_retries_rate_limit_once(monkeypatch):
+    calls = {"n": 0}
+    sleeps: list[float] = []
+
+    async def mock_sleep(delay: float):
+        sleeps.append(delay)
+
+    async def mock_get(self, url, **kw):
+        calls["n"] += 1
+        if calls["n"] == 1:
+            return _response(status=429, json={"error": "rate limit"})
+        return _response(json={
+            "web": {"results": [{"title": "Recovered", "url": "https://example.com", "description": "ok"}]}
+        })
+
+    monkeypatch.setattr("nanobot.agent.tools.web.asyncio.sleep", mock_sleep)
+    monkeypatch.setattr(httpx.AsyncClient, "get", mock_get)
+
+    tool = _tool(provider="brave", api_key="brave-key")
+    result = await tool.execute(query="nanobot", count=1)
+
+    assert calls["n"] == 2
+    assert "Recovered" in result
+    assert sleeps == [1.0]
+
+
+@pytest.mark.asyncio
+async def test_brave_search_returns_clear_rate_limit_after_retries(monkeypatch):
+    calls = {"n": 0}
+
+    async def mock_sleep(delay: float):
+        return None
+
+    async def mock_get(self, url, **kw):
+        calls["n"] += 1
+        return _response(status=429, json={"error": "rate limit"})
+
+    monkeypatch.setattr("nanobot.agent.tools.web.asyncio.sleep", mock_sleep)
+    monkeypatch.setattr(httpx.AsyncClient, "get", mock_get)
+
+    tool = _tool(provider="brave", api_key="brave-key")
+    result = await tool.execute(query="nanobot", count=1)
+
+    assert calls["n"] == 2
+    assert "Brave search rate limited" in result
+    assert "consecutive web_search" in result
+
+
 @pytest.mark.asyncio
 async def test_tavily_search(monkeypatch):
     async def mock_post(self, url, **kw):