pub const REASONING_PLACEHOLDER: &str = "(no reasoning recorded)";Expand description
Sentinel emitted on outbound reasoning_content when we have nothing to
echo (cross-provider handoff, pre-fix session, non-thinking model that
still tool-called) but the receiving API requires the field to be
non-empty (DeepSeek V4 thinking mode rejects empty strings).
TurnRunner::Done checks reasoning_buf against this exact value and
refuses to promote it back into the assistant text channel — without that
gate, a buggy gateway echoing our placeholder caused silent
Nailed it · 0 tok mid-task stops (user reported (no reasoning recorded) showing up as the only assistant output after 17 reading
rounds).