Citations And Source Grounding

Operator omits return_citations on POST /chat/completions and expects the response.citations[] array to populate by default.

Set return_citations=true explicitly on every request where source attribution is required downstream. The default behavior should not be assumed [REQUIRES-VERIFICATION] across model versions — opt in by setting the flag and verify response.citations is present and non-empty before rendering.

Assistant content contains markers like 'The deal closed in 2025 [1] for $40M [2].' citations=['https://nyt.com/...', 'https://wsj.com/...'].

[n] is 1-indexed and maps to citations[n-1]. Render [1] as a link to citations[0]. Preserve the bracketed marker if it is part of the model's anchoring; rewrite as a hyperlink only after confirming the index→URL mapping per request.

Client renders citations[] progressively as it accumulates streaming deltas; expects citations to populate incrementally.

Per Sonar SSE, citations appear in the response body (non-streaming) or on the terminating chunk (streaming) — not progressively per delta. Render citations only after the stream completes or the terminal payload arrives. UI should show 'finding sources…' until the citation block lands.