OpenAI's assistant can run a local server but blocks opening localhost in its own browser
No-Papaya-3352 · reddit · 2026-10-07
Testing a browser game with OpenAI's desktop assistant, the author hit a contradictory limitation: the assistant can run code on its cloud machine, start a local web server, and even confirm via terminal that it returns 200 OK with "Hello World" — but opening 127.0.0.1:8765 in its own browser fails with ERRBLOCKEDBYCLIENT.
- Restarting didn't help
- Suggestions like typing the address manually or trying another browser were treated by the assistant as attempts to bypass restrictions
- The author argues that being able to build but not visually test is a major limitation for development work, and the rationale given is confusing
They're asking whether it's a bug, an intentional restriction, or a broken link between the dev environment and browser.
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