feat(anthropic): web fetch beta (#32894)

Note: citations are broken until Anthropic fixes their API

docs/docs/integrations/chat/anthropic.ipynb

@@ -970,8 +970,8 @@
    "source": [
     "### In tool results (agentic RAG)\n",
     "\n",
-    ":::info Requires ``langchain-anthropic>=0.3.17``\n",
-    "\n",
+    ":::info\n",
+    "Requires ``langchain-anthropic>=0.3.17``\n",
     ":::\n",
     "\n",
     "Claude supports a [search_result](https://docs.anthropic.com/en/docs/build-with-claude/search-results) content block representing citable results from queries against a knowledge base or other custom source. These content blocks can be passed to claude both top-line (as in the above example) and within a tool result. This allows Claude to cite elements of its response using the result of a tool call.\n",
@@ -1290,6 +1290,58 @@
     "print(f\"Key Points: {result.key_points}\")"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "c580c20a",
+   "metadata": {},
+   "source": [
+    "### Web fetching\n",
+    "\n",
+    "Claude can use a [web fetching tool](https://docs.anthropic.com/en/docs/agents-and-tools/tool-use/web-fetch-tool) to run searches and ground its responses with citations."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "5cf6ad08",
+   "metadata": {},
+   "source": [
+    ":::info\n",
+    "Web search tool is supported since ``langchain-anthropic>=0.3.20``\n",
+    ":::"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "c4804be1",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from langchain_anthropic import ChatAnthropic\n",
+    "\n",
+    "llm = ChatAnthropic(\n",
+    "    model=\"claude-3-5-haiku-latest\",\n",
+    "    betas=[\"web-fetch-2025-09-10\"],  # Enable web fetch beta\n",
+    ")\n",
+    "\n",
+    "tool = {\"type\": \"web_fetch_20250910\", \"name\": \"web_fetch\", \"max_uses\": 3}\n",
+    "llm_with_tools = llm.bind_tools([tool])\n",
+    "\n",
+    "response = llm_with_tools.invoke(\n",
+    "    \"Please analyze the content at https://example.com/article\"\n",
+    ")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "088c41d0",
+   "metadata": {},
+   "source": [
+    ":::warning\n",
+    "Note: you must add the `'web-fetch-2025-09-10'` beta header to use this tool.\n",
+    ":::"
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "1478cdc6-2e52-4870-80f9-b4ddf88f2db2",
@@ -1299,14 +1351,14 @@
     "\n",
     "Claude can use a [code execution tool](https://docs.anthropic.com/en/docs/agents-and-tools/tool-use/code-execution-tool) to execute Python code in a sandboxed environment.\n",
     "\n",
-    ":::info Code execution is supported since ``langchain-anthropic>=0.3.14``\n",
-    "\n",
+    ":::info\n",
+    "Code execution is supported since ``langchain-anthropic>=0.3.14``\n",
     ":::"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": null,
    "id": "2ce13632-a2da-439f-a429-f66481501630",
    "metadata": {},
    "outputs": [],
@@ -1315,7 +1367,7 @@
     "\n",
     "llm = ChatAnthropic(\n",
     "    model=\"claude-sonnet-4-20250514\",\n",
-    "    betas=[\"code-execution-2025-05-22\"],\n",
+    "    betas=[\"code-execution-2025-05-22\"],  # Enable code execution beta\n",
     ")\n",
     "\n",
     "tool = {\"type\": \"code_execution_20250522\", \"name\": \"code_execution\"}\n",
@@ -1326,6 +1378,16 @@
     ")"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "a6b5e15a",
+   "metadata": {},
+   "source": [
+    ":::warning\n",
+    "Note: you must add the `'code_execution_20250522'` beta header to use this tool.\n",
+    ":::"
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "24076f91-3a3d-4e53-9618-429888197061",
@@ -1404,14 +1466,14 @@
     "\n",
     "Claude can use a [MCP connector tool](https://docs.anthropic.com/en/docs/agents-and-tools/mcp-connector) for model-generated calls to remote MCP servers.\n",
     "\n",
-    ":::info Remote MCP is supported since ``langchain-anthropic>=0.3.14``\n",
-    "\n",
+    ":::info\n",
+    "Remote MCP is supported since ``langchain-anthropic>=0.3.14``\n",
     ":::"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": null,
    "id": "22fc4a89-e6d8-4615-96cb-2e117349aebf",
    "metadata": {},
    "outputs": [],
@@ -1423,17 +1485,17 @@
     "        \"type\": \"url\",\n",
     "        \"url\": \"https://mcp.deepwiki.com/mcp\",\n",
     "        \"name\": \"deepwiki\",\n",
-    "        \"tool_configuration\": {  # optional configuration\n",
+    "        \"tool_configuration\": {  # Optional configuration\n",
     "            \"enabled\": True,\n",
     "            \"allowed_tools\": [\"ask_question\"],\n",
     "        },\n",
-    "        \"authorization_token\": \"PLACEHOLDER\",  # optional authorization\n",
+    "        \"authorization_token\": \"PLACEHOLDER\",  # Optional authorization\n",
     "    }\n",
     "]\n",
     "\n",
     "llm = ChatAnthropic(\n",
     "    model=\"claude-sonnet-4-20250514\",\n",
-    "    betas=[\"mcp-client-2025-04-04\"],\n",
+    "    betas=[\"mcp-client-2025-04-04\"],  # Enable MCP beta\n",
     "    mcp_servers=mcp_servers,\n",
     ")\n",
     "\n",
@@ -1443,6 +1505,16 @@
     ")"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "0d6d7197",
+   "metadata": {},
+   "source": [
+    ":::warning\n",
+    "Note: you must add the `'mcp-client-2025-04-04'` beta header to use this tool.\n",
+    ":::"
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "2fd5d545-a40d-42b1-ad0c-0a79e2536c9b",