FEATUREDAI HOT (Curated Pool)· aihot-apiZH18:59 · 09·22
→Anthropic Releases Claude Opus 5.5: Fable 5.1-Level Performance at 40% Lower Running Cost Than Opus 5
Anthropic launched Claude Opus 5.5, the first model in its Claude 5.5 family. The team says it matches Fable 5.1 on most work while costing 40% less to run than Opus 5. It leads Anthropic's internal benchmarks on agentic coding, computer use, and knowledge work. It's not a clean sweep—GPT-6 Astra still leads on Terminal-Bench-Science and AutomationBench. Pricing is $4 per 1M input tokens, $20 per 1M output tokens, and cache reads drop to $0.20, a 60% cut that matters most for agentic and coding costs. Output is over 30% faster than Opus 5, with a fast mode offering 2.5x speed. The model is API-only, no open weights. One early tester migrated 680,000 lines of code in under a day.
#Anthropic#Claude Opus 5.5#Claude Fable 5.1
why featured
Featured · importance 88 · hook + knowledge + resonance
editor take
Anthropic squeezed Fable 5.1-level performance into Opus 5.5 at 40% lower running cost and a 60% cache-read cut—clearly targeting agent and coding API spend.
sharp
The pricing tells a clearer story than the benchmarks. Opus 5.5 leads Anthropic's own evals on agentic coding, computer use, and knowledge work, but GPT-6 Astra still wins on Terminal-Bench-Science and AutomationBench—so it's not a clean sweep. The real move is cost: $4/1M input, $20/1M output, and cache reads slashed 60% to $0.20. Anyone running agent loops knows cache reads pile up fast when tools get called repeatedly; that cut matters more than the 40% headline reduction. Output is over 30% faster than Opus 5, with a 2.5x fast mode. One early tester claims 680,000 lines migrated in under a day—plausible, but no task details were given. API-only, no open weights, so self-hosting is off the table. I'd read this as Anthropic defending its high-end API position: Fable 5.1-level work, but the bill looks a lot friendlier.
HKR breakdown
hook ✓knowledge ✓resonance ✓