xtekky/gpt4free · warning · MissingRequirementsError

Install "webview" package

Error message

Install "webview" package

What it means

MissingRequirementsError raised by g4f.requests.get_args_from_webview when the optional 'webview' package (pywebview) is absent: this helper loads a URL in a hidden desktop webview window to scrape real browser headers/args, so it hard-requires webview and a working GUI stack. Note the has_webview guard means the error fires before any window is created.

Source

Thrown at g4f/requests/__init__.py:74

from .. import debug
from .raise_for_status import raise_for_status
from ..errors import MissingRequirementsError
from ..typing import Cookies
from ..cookies import BrowserConfig, get_cookies_dir
from .defaults import DEFAULT_HEADERS, WEBVIEW_HAEDERS

if not has_curl_cffi:

    class Session:
        def __init__(self, **kwargs):
            raise MissingRequirementsError(
                'Install "curl_cffi" package | pip install -U curl_cffi'
            )


async def get_args_from_webview(url: str) -> dict:
    if not has_webview:
        raise MissingRequirementsError('Install "webview" package')
    window = webview.create_window("", url, hidden=True)
    await asyncio.sleep(2)
    body = None
    while body is None:
        try:
            await asyncio.sleep(1)
            body = window.dom.get_element("body:not(.no-js)")
        except Exception:
            ...
    headers = {
        **WEBVIEW_HAEDERS,
        "User-Agent": window.evaluate_js("this.navigator.userAgent"),
        "Accept-Language": window.evaluate_js("this.navigator.language"),
        "Referer": window.real_url,
    }
    cookies = [list(*cookie.items()) for cookie in window.get_cookies()]
    cookies = {name: cookie.value for name, cookie in cookies}
    window.destroy()

View on GitHub (pinned to 973504e177)

Solutions

1. Install the package: pip install -U webview (pywebview) if your environment has a GUI/display.
2. On headless machines, avoid the webview path entirely — use providers that do not need it, or provide args (headers/cookies) explicitly.
3. In Docker/Linux servers, run under xvfb-run if you truly need the webview flow, or prefer curl_cffi-based providers.
4. Guard the call: check g4f.requests.has_webview before invoking get_args_from_webview.

Example fix

# before
args = await get_args_from_webview(url)  # MissingRequirementsError on headless box

# after
from g4f.requests import has_webview, Session
if has_webview:
    args = await get_args_from_webview(url)
else:
    args = {'headers': DEFAULT_HEADERS}  # fall back to static browser headers

from g4f.requests import has_webview
if not has_webview:
    raise RuntimeError('pywebview not installed; webview header-scraping unavailable — '
                       'pass headers explicitly or use a curl_cffi-based provider')

def webview_available() -> bool:
    import importlib.util
    return importlib.util.find_spec('webview') is not None and os.environ.get('DISPLAY') is not None

from g4f.errors import MissingRequirementsError
try:
    args = await get_args_from_webview(url)
except MissingRequirementsError:
    args = {'headers': DEFAULT_HEADERS}  # degrade gracefully without the GUI stack

When it happens

Trigger: Calling get_args_from_webview(url) (used by some providers to harvest Cloudflare-passing headers) in an environment without pip install pywebview — typical headless servers also fail later at window creation even with the package installed.

Common situations: Deploying g4f to headless Linux servers or containers where the webview path is attempted; minimal installs without the webview extra; CI environments with no display server.

Related errors

• Install "beautifulsoup4" package
• Install "curl_cffi" package | pip install -U curl_cffi
• cloudscraper library is required for Yupp provider | install
• MarkItDown is not installed. Please install it with `pip ins
• Aliyun captcha SDK failed to load

AI-assisted analysis of xtekky/gpt4free@973504e177 (2026-08-14). Data as JSON: /api/errors/4e62f3a8af3a2751. Report an issue: GitHub.