We’re seeing web search citation markers bleed into the actual text output on the Responses API with gpt-5.5.
The model emits citation spans wrapped in invisible unicode (U+E200 to open, U+E201 to close, U+E202 between the inner tokens) and these aren’t being stripped before the text comes back to us. They’re invisible characters, so the moment anything renders the text and drops them, you’re left with the visible junk in the middle of the response, e.g. citeturn0search2turn0search4
The multi-source form (\ue200cite\ue202turn0search0\ue202turn0search1\ue201) seems more likely to show up visibly.
Screencap from one of our streams:
These come through alongside proper structured url_citation annotations on the text block, so the citation data itself is fine, it’s just the inline text that’s dirty.
Rough repro: Responses API, gpt-5.5, streaming, web_search tool enabled. Force a turn that searches the web and cites an official page inline, e.g. ask it to state some current fact and cite the source in its reply. Prompting it to cite the source inline, especially multiple sources, makes the markers show up.