The AWS Kiro (https://kiro.dev) spec-driven coding harness operates this way in Auto mode which offers the base token rate.
Manually-specifying Sonnet or Opus is a multiplier on the base token rate; specifying Qwen fractions it. Left to its own, it presumably uses the heavier models to create the plan and orchestrate the work; the bite-sized task definitions are delegated to smaller models.
Manually-specifying Sonnet or Opus is a multiplier on the base token rate; specifying Qwen fractions it. Left to its own, it presumably uses the heavier models to create the plan and orchestrate the work; the bite-sized task definitions are delegated to smaller models.