OpenAI cuts GPT-5.6 Sol API and credit prices by over 20% for three months

OpenAI updated the GPT-5.6 announcement page on August 21: API and credit pricing for GPT-5.6 Sol drops by over 20% for the next three months. The API pricing page lists promotional Sol pricing of $4.00 per 1M input / $20.00 per 1M output tokens for short context ($8.00/$30.00 long context), cached input at 10% of the input price, and states the promotional pricing is available 'at least through November 21, 2026'. Family context: Terra at $2.00/$12.00 and Luna at $0.20/$1.20 (short context); Batch and Flex tiers are 50% off standard (Sol $2.00/$10.00); Fast mode is 2x. The GPT-5.6 family (Sol/Terra/Luna) reached GA on 2026-08-18, with Luna positioned as the low-cost tier powering Replit's Free Mode (announced 8/18-19, just before this window). The cut moves in the opposite direction to DeepSeek V4-Pro's large price increase effective 2026-08-16.

For teams running output-heavy, cost-sensitive agent pipelines, a >20% cut on the frontier flagship changes routing math: with Batch/Flex at $2.00/$10.00, Sol moves into mid-tier cost territory while keeping frontier quality. Two planning cautions. First, it is explicitly promotional — 'at least through Nov 21' means budgets and routing policies must model reversion risk after the window. Second, per the item-level API-migration audit (ev-20260819-03), aggregate benchmark gains can hide item-level regressions, so price alone should not drive a blind all-in migration to Sol.