The #96155 fix (#96644) made the turn-prologue preflight estimate the
checkpoint-pruned native Responses payload, but the independent mid-turn
pre-API pressure guard in conversation_loop still estimated the full
assembled durable history. On a compacted native-Codex session the
generic figure overstates the wire by orders of magnitude (the issue's
deterministic probe: 1,037,241 generic vs 6,036 pruned, 171x), so the
guard false-tripped a 600-second local compression the main request
never needed — the live sequence shows the actual request then fit at
164k input tokens against a 765k threshold (#96995).
Extract the guard's pressure figure into _midturn_request_pressure_tokens
and mirror the turn-prologue: when native Responses compaction is proven
eligible, use estimate_native_responses_preflight_tokens (system prompt
and tools included, checkpoint-pruned); otherwise keep the generic
message+tools figure. Passing the assembled api_messages alongside
effective_system counts the system prompt exactly once — the estimator's
converter skips system-role rows and adds the prompt separately.
total_chars (verbose log proxy) and the non-codex paths are unchanged.
Fixes#96995
Automatic preflight used the full durable transcript even when the
Codex Responses request would prune around a native compaction
checkpoint. That false-triggered a 600s local summary against history
the main request never sent. Estimate the converted, checkpoint-pruned
payload when native compaction is eligible, and keep the generic
estimate as the conservative fallback.
liuhao1024