NanmiCoder/MediaCrawler · error · RuntimeError

CDP connection failed

Error message

CDP connection failed

What it means

Error "CDP connection failed" thrown in NanmiCoder/MediaCrawler.

Source

Thrown at tools/cdp_browser.py:354

                    utils.logger.info(
                        f"[CDPBrowserManager] Connecting to existing browser via discovered CDP: {ws_url}"
                    )
                    self.browser = await playwright.chromium.connect_over_cdp(
                        ws_url, timeout=config.BROWSER_LAUNCH_TIMEOUT * 1000
                    )
            else:
                # For launched browser, get WebSocket URL first
                ws_url = await self._get_browser_websocket_url(self.debug_port)
                utils.logger.info(f"[CDPBrowserManager] Connecting to browser via CDP: {ws_url}")
                self.browser = await playwright.chromium.connect_over_cdp(ws_url)

            if self.browser.is_connected():
                utils.logger.info("[CDPBrowserManager] Successfully connected to browser")
                utils.logger.info(
                    f"[CDPBrowserManager] Browser contexts count: {len(self.browser.contexts)}"
                )
            else:
                raise RuntimeError("CDP connection failed")

        except Exception as e:
            utils.logger.error(f"[CDPBrowserManager] CDP connection failed: {e}")
            raise

    async def _create_browser_context(
        self, playwright_proxy: Optional[Dict] = None, user_agent: Optional[str] = None
    ) -> BrowserContext:
        """
        Create or get browser context
        """
        if not self.browser:
            raise RuntimeError("Browser not connected")

        # Get existing context or create new context
        contexts = self.browser.contexts

        if contexts:

View on GitHub (pinned to d6f7c5bb90)

Solutions

1. Ensure the browser process is still alive and did not exit after launch; check logs for a startup crash.
2. Verify config.CDP_DEBUG_PORT matches the port the browser is listening on (check chrome://inspect/#remote-debugging or the browser launch output).
3. Increase config.BROWSER_LAUNCH_TIMEOUT if the browser is slow to start on your system.
4. If connecting to an existing browser on Chrome 136+, accept the confirmation dialog shown in the browser window, then retry.

When it happens

Trigger: Thrown at tools/cdp_browser.py:354 when the library encounters an invalid state.

Common situations: playwright.chromium.connect_over_cdp returned but browser.is_connected() is False, or the connection dropped immediately. Occurs when the WebSocket URL is stale, the browser rejected the connection (confirmation dialog not accepted in Chrome 136+), the browser crashed during launch, or BROWSER_LAUNCH_TIMEOUT is too short. Defensive fix: retry the connection after prompting the user to accept the browser confirmation dialog, and validate the browser process before connecting.

AI-assisted analysis of NanmiCoder/MediaCrawler@d6f7c5bb90 (2026-08-15). Data as JSON: /api/errors/6126a7b8a7128db7. Report an issue: GitHub.