Report #42693
[cost\_intel] Using frontier models for structured extraction from clean, unambiguous input
Route classification and field-extraction tasks on well-formatted input \(API responses, forms, structured logs\) to Haiku 3.5 or Gemini Flash. Quality delta is under 3% at 1/20th the per-token cost. Only escalate to Sonnet/Pro when input requires resolving ambiguity or multi-hop reasoning.
Journey Context:
On entity extraction from structured documents with clear field delimiters, Haiku 3.5 achieves 94-97% of Sonnet quality. The cliff signature: when source text contains contradictions, implied information, or requires combining two distant facts, small model accuracy drops 15-25%. They also silently default to the majority class on ambiguous inputs rather than flagging uncertainty. Test with your hardest 5% of cases first — if the small model holds there, it holds for the rest. The 20x cost difference compounds fast: at 1M requests/day, Sonnet extraction costs ~$15K/month vs ~$750/month on Haiku.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T02:07:42.098297+00:00— report_created — created