(Created on )

Puppeteer: Invalid connection options

Internal connection setup received mutually invalid transport/endpoint options.


Internal connection setup received mutually invalid transport/endpoint options.

Error message

Invalid connection options

How this error happens

Connection setup must receive a usable single endpoint source. In a browser-only build, a Node-specific channel lookup is not a supported way to create the transport.

The failing snippet assumes Puppeteer’s browser-only build, not its normal Node.js launcher.

await puppeteer.connect({
    channel: "chrome",
});

An empty object or several connection sources usually fails earlier with the “Exactly one” validation. This internal fallback concerns a source that cannot create a transport in the current environment.

How to fix

Provide the actual WebSocket endpoint of a running managed browser.

const browser = await puppeteer.connect({
    browserWSEndpoint: "ws://127.0.0.1:9222/devtools/browser/example",
});

Things to keep in mind

Replace the placeholder endpoint with a real browser endpoint. Browser pages also face mixed-content and network-access restrictions. Do not expose a browser debugging endpoint publicly.

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