LLMs, GenAI, RAG, agents, evaluation · insight-1638

Decide per surface whether to stream or to buffer, because streamed text is shown before it is checked

Situation
Streaming is switched on for responsiveness, while the same endpoint feeds output checks such as schema validation, citation verification or policy filters.
Action
Stream only prose that is safe to show before verification. Buffer structured outputs and cited answers until checks pass, or stream a provisional draft explicitly marked unverified and replace it on completion.
Reason
Checks that need the whole output cannot run on a prefix, so streaming moves validation after display; latency gain and verification are in direct tension and the choice depends on the harm of a bad line.
Boundary
Chat and copilot interfaces with post-generation validation, redaction or citation checks.

Symptom or risk

Users see claims, links or personal data that the validator would have rejected, and retraction is impossible once text has been displayed.

Low-risk drafting aids where the user is the only reader and edits everything.

Buffering raises perceived latency; a progress state and shorter outputs recover part of it.

Running the checks only in logs after the fact, so violations are measured but still delivered.