Anthropic launches Claude Opus 5, near-Fable 5 performance at half the price

Anthropic's Claude Opus 5 lands about two months after the previous Opus upgrade, positioned explicitly as a cost-efficiency play: near-Fable 5 intelligence at roughly half the cost. It posts state-of-the-art scores on coding and knowledge-work evaluations and, per François Chollet, set a new SOTA on ARC-AGI-3 at 30.2% — notable because ARC-AGI measures novel problem-solving where scaling has historically bought the least. It is now the default model on Claude Max, available to Claude Pro, and generally available on Amazon Bedrock with zero-data-retention (ZDR) compatibility.

Mechanically, AWS's Swami Sivasubramanian says Opus 5 powers long-running agents that work for hours or overnight, recover from errors, navigate codebases like an experienced engineer, and push back on flawed instructions rather than executing blindly, breaking complex jobs into sub-agents that need less supervision. Anthropic's Boris Cherny highlighted that Opus 5 is the company's least prompt-injectable model yet across its PI evals — a meaningful security claim given the week's rogue-agent headlines.

Competitively, Opus 5 arrives as Chinese models (Qwen 3.8-Max, Kimi K3, DeepSeek V4) close the gap at lower cost, and Anthropic is clearly answering on price. But skeptics pushed back hard: an r/singularity thread with 1,528 upvotes accused Anthropic of 'benchmaxxing' the ARC-AGI score, and LlamaIndex's Jerry Liu benchmarked Opus 5 as merely on par with Opus 4.8 on document parsing — worse than the cheaper Gemini 3.6 Flash on dense tables. Readers should watch whether the price cut holds up against the open-weight wave and whether real-world agentic reliability matches the eval numbers.