Every THE D[AI]LY BRIEF article on cache hit rate — enterprise AI analysis, benchmarks, vendor comparisons, and ROI frameworks for technology and business leaders. Updated as new coverage publishes.
On a 30-turn agent loop, prompt caching saves 80-89% depending on the provider, not 90%. A timestamp in the system prompt drops Claude's saving to 6%, and a volatile tool definition makes caching cost more than not caching.
October 1, 2026 · 17 min read
Anthropic cut Claude Fable 5.1 cache reads 75% to $0.25/MTok, half of Opus 5's rate on a model with twice the base input price. But Opus 5 stays cheaper until cache reads pass a third of your bill, and Anthropic's own savings ceiling of 45% falls short of the 50% crossover.
September 1, 2026 · 15 min read
Manifest killed its four-tier LLM router after four months and 7,000 users, and the arithmetic explains why: cache reads bill at 10% of base input, so routing an agent step to a model 2.5x cheaper makes it 3.5x more expensive. Route at the session boundary, not the request.
August 1, 2026 · 15 min read