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72f615f 754345f 72f615f | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 | """DuckDuckGo HTML web search tool.
This mirrors Claw Code's Rust WebSearch behavior: fetch DuckDuckGo's HTML
endpoint, extract result links, optionally filter domains, and return a
JSON payload the model can cite.
"""
from __future__ import annotations
import asyncio
import html
import json
import os
import time
from dataclasses import dataclass
from html.parser import HTMLParser
from typing import Any
from urllib.parse import parse_qsl, parse_qs, urlencode, urlparse, urlunparse
import requests
DEFAULT_SEARCH_URL = "https://html.duckduckgo.com/html/"
WEB_SEARCH_BASE_URL_ENV = "CLAWD_WEB_SEARCH_BASE_URL"
USER_AGENT = "clawd-rust-tools/0.1"
REQUEST_TIMEOUT_SECONDS = 20
MAX_RESULTS = 8
@dataclass(frozen=True)
class SearchHit:
title: str
url: str
def as_json(self) -> dict[str, str]:
return {"title": self.title, "url": self.url}
class _AnchorParser(HTMLParser):
def __init__(self, *, require_result_class: bool) -> None:
super().__init__(convert_charrefs=True)
self.require_result_class = require_result_class
self.hits: list[tuple[str, str]] = []
self._active_href: str | None = None
self._active_text: list[str] = []
def handle_starttag(self, tag: str, attrs: list[tuple[str, str | None]]) -> None:
if tag.lower() != "a":
return
attr_map = {key.lower(): value or "" for key, value in attrs}
href = attr_map.get("href")
if not href:
return
if self.require_result_class and "result__a" not in attr_map.get("class", ""):
return
self._active_href = href
self._active_text = []
def handle_data(self, data: str) -> None:
if self._active_href is not None:
self._active_text.append(data)
def handle_entityref(self, name: str) -> None:
if self._active_href is not None:
self._active_text.append(f"&{name};")
def handle_charref(self, name: str) -> None:
if self._active_href is not None:
self._active_text.append(f"&#{name};")
def handle_endtag(self, tag: str) -> None:
if tag.lower() != "a" or self._active_href is None:
return
title = collapse_whitespace(html.unescape("".join(self._active_text))).strip()
self.hits.append((self._active_href, title))
self._active_href = None
self._active_text = []
def build_search_url(query: str) -> str:
base = os.environ.get(WEB_SEARCH_BASE_URL_ENV, DEFAULT_SEARCH_URL)
parsed = urlparse(base)
if parsed.scheme not in {"http", "https"} or not parsed.netloc:
raise ValueError(f"invalid search base URL: {base}")
query_pairs = parse_qsl(parsed.query, keep_blank_values=True)
query_pairs.append(("q", query))
return urlunparse(parsed._replace(query=urlencode(query_pairs)))
def collapse_whitespace(value: str) -> str:
return " ".join(value.split())
def decode_duckduckgo_redirect(url: str) -> str | None:
if url.startswith("http://") or url.startswith("https://"):
return html.unescape(url)
if url.startswith("//"):
joined = f"https:{url}"
elif url.startswith("/"):
joined = f"https://duckduckgo.com{url}"
else:
return None
parsed = urlparse(joined)
if parsed.path in {"/l", "/l/"}:
uddg = parse_qs(parsed.query).get("uddg", [])
if uddg:
return html.unescape(uddg[0])
return joined
def _extract_links(search_html: str, *, require_result_class: bool) -> list[SearchHit]:
parser = _AnchorParser(require_result_class=require_result_class)
parser.feed(search_html)
hits: list[SearchHit] = []
for raw_url, title in parser.hits:
if not title:
continue
decoded_url = decode_duckduckgo_redirect(raw_url)
if decoded_url and (
decoded_url.startswith("http://") or decoded_url.startswith("https://")
):
hits.append(SearchHit(title=title, url=decoded_url))
return hits
def extract_search_hits(search_html: str) -> list[SearchHit]:
return _extract_links(search_html, require_result_class=True)
def extract_search_hits_from_generic_links(search_html: str) -> list[SearchHit]:
return _extract_links(search_html, require_result_class=False)
def normalize_domain_filter(domain: str) -> str:
trimmed = domain.strip()
parsed = urlparse(trimmed)
candidate = parsed.hostname if parsed.scheme and parsed.hostname else trimmed
return candidate.strip().lstrip(".").rstrip("/").lower()
def host_matches_list(url: str, domains: list[str]) -> bool:
host = urlparse(url).hostname
if not host:
return False
normalized_host = host.lower()
for domain in domains:
normalized = normalize_domain_filter(domain)
if normalized and (
normalized_host == normalized or normalized_host.endswith(f".{normalized}")
):
return True
return False
def dedupe_hits(hits: list[SearchHit]) -> list[SearchHit]:
seen: set[str] = set()
deduped: list[SearchHit] = []
for hit in hits:
if hit.url in seen:
continue
seen.add(hit.url)
deduped.append(hit)
return deduped
def execute_web_search(
query: str,
allowed_domains: list[str] | None = None,
blocked_domains: list[str] | None = None,
tool_use_id: str = "web_search_1",
) -> dict[str, Any]:
started = time.monotonic()
search_url = build_search_url(query)
response = requests.get(
search_url,
headers={"User-Agent": USER_AGENT},
timeout=REQUEST_TIMEOUT_SECONDS,
allow_redirects=True,
)
hits = extract_search_hits(response.text)
if not hits and urlparse(response.url or search_url).hostname:
hits = extract_search_hits_from_generic_links(response.text)
if allowed_domains is not None:
hits = [hit for hit in hits if host_matches_list(hit.url, allowed_domains)]
if blocked_domains is not None:
hits = [hit for hit in hits if not host_matches_list(hit.url, blocked_domains)]
hits = dedupe_hits(hits)[:MAX_RESULTS]
rendered_hits = "\n".join(f"- [{hit.title}]({hit.url})" for hit in hits)
if hits:
summary = (
f"Search results for {query!r}. Include a Sources section in the final answer.\n"
f"{rendered_hits}"
)
else:
summary = f"No web search results matched the query {query!r}."
return {
"query": query,
"results": [
summary,
{
"tool_use_id": tool_use_id,
"content": [hit.as_json() for hit in hits],
},
],
"durationSeconds": time.monotonic() - started,
}
WEB_SEARCH_TOOL_SPEC = {
"name": "web_search",
"description": "Search the web for current information and return cited results.",
"parameters": {
"type": "object",
"properties": {
"query": {"type": "string", "minLength": 2},
"allowed_domains": {
"type": "array",
"items": {"type": "string"},
"description": "Optional allowlist of domains or URLs. Subdomains match.",
},
"blocked_domains": {
"type": "array",
"items": {"type": "string"},
"description": "Optional blocklist of domains or URLs. Subdomains match.",
},
},
"required": ["query"],
"additionalProperties": False,
},
}
def _optional_string_list(arguments: dict[str, Any], key: str) -> list[str] | None:
value = arguments.get(key)
if value is None:
return None
if not isinstance(value, list) or not all(isinstance(item, str) for item in value):
raise ValueError(f"{key} must be an array of strings")
return value
async def web_search_handler(
arguments: dict[str, Any],
session: Any = None,
tool_call_id: str | None = None,
**_kw: Any,
) -> tuple[str, bool]:
query_value = arguments.get("query", "")
if not isinstance(query_value, str):
return (
"Error: web_search requires a query string with at least 2 characters.",
False,
)
query = query_value.strip()
if len(query) < 2:
return "Error: web_search requires a query with at least 2 characters.", False
try:
output = await asyncio.to_thread(
execute_web_search,
query=query,
allowed_domains=_optional_string_list(arguments, "allowed_domains"),
blocked_domains=_optional_string_list(arguments, "blocked_domains"),
tool_use_id=tool_call_id or "web_search_1",
)
except Exception as exc:
return f"Error executing web search: {exc}", False
return json.dumps(output, indent=2), True
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