Claude Opus 4.8
Model ● Covered in 35 stories + Follow
Claude Opus 4.8 is an Anthropic large language model referenced across multiple recent reports as a baseline for evaluating agent and coding performance. Coverage includes comparisons in which Opus 4.8 was outperformed on specific agent tasks (such as independently replicating research results and improving cost/accuracy tradeoffs in a legal query agent) and was used in research tests assessing the limits of agent-driven scientific work. It also appears in tooling benchmarks, where systems like Databricks’ minimal coding harness reported strong pass rates and lower context/cost when using Opus 4.8.
Updated 14 September 2026
Specifications
No specifications recorded yet.
Latest developments
AI’s recursive self-improvement might not come so quickly after all
MIT Technology Review · 4 weeks ago ·
31
Pi, Minimal and Performant
Earendil · 1 month ago ·
7
Cogent AI Team Releases VR-1: A Frontier Cyber Reasoning Model That Composes and Verifies Enterprise Attack Paths
MarkTechPost · 1 month ago ·
7
[AINews] Much ado about Open Weights
Latent Space · 1 month ago ·
33
Claude Opus 5: The System Card
Zvi (Don't Worry About the Vase) · 1 month ago ·
3
Introducing Claude Opus 5
Simon Willison's Weblog · 1 month ago ·
49
August 2026
- Inherent, founded by DeepMind alumni, says its AI ‘teammate’ just outperformed Anthropic and OpenAI at replicating research
- Engram and Harvey trained a legal agent that cut query costs and improved accuracy
- AI’s recursive self-improvement might not come so quickly after all
- Pi, Minimal and Performant
- Cogent AI Team Releases VR-1: A Frontier Cyber Reasoning Model That Composes and Verifies Enterprise Attack Paths
July 2026
Anthropic releases Claude Opus 5, matching Fable 5 capabilities at half the price Model release
Cursor launches Cursor Router, an AI model classifier that reduces coding task costs by 30-50% through intelligent request routing Feature update
Moonshot AI releases Kimi K3, a 2.8 trillion parameter open-weight model achieving frontier-class performance Open source release
Moonshot AI releases Kimi K3, a 2.8 trillion parameter open-weight model with API pricing and delayed weights availability Model release
Moonshot AI released Kimi K3, an open-weight large language model Model release
Anthropic restores Claude Fable 5 after US government suspension over cybersecurity concerns Incident
Claude Sonnet 5 Release and Tokenizer Efficiency Comparison with Competitors Model release
Anthropic extends Claude Fable 5 free access through July 19 for paid subscribers Feature update
xAI launches Grok 4.5, an Opus-class large language model developed in partnership with Cursor Model release
Analysis reveals Claude Sonnet 5 has higher effective costs and lower quality than predecessor despite lower per-token pricing Feature update
Fable 5 released and achieves top performance on CursorBench benchmark Model release
Anthropic redeployed Fable 5 AI model with enhanced safety restrictions following government export controls Feature update
- [AINews] Much ado about Open Weights
- Claude Opus 5: The System Card
- Introducing Claude Opus 5
- Meet the New Claude Opus 5: Frontier-Class Agentic Coding and Computer Use at Unchanged Opus Pricing
- Opus 5 costs a third of the price — and that’s actually the problem
- Cursor, Ramp, and Meta are all building model routers — but two have major model ambitions themselves
- Cursor Releases Cursor Router: A Request-Level Classifier Delivering Frontier Coding Quality at 30–50% Lower Cost
- China’s Low-Priced Z.ai Model Is Exposing Costly Coder Habits
- LWiAI Podcast #247 - Opus 4.8, MAI, Anthropic IPO, Minimax-M3
- I trust Claude for everything. This test made me rethink that.
- Kimi K3 tops Arena’s coding leaderboard — and it’s open-weight
- [AINews] Kimi K3 2.8T-A50B: the largest open model ever released; Opus 4.8-class at Sonnet 5 pricing
- Moonshot’s upcoming Kimi 3 is expected to close the gap with Anthropic’s Opus 4.8
- Restoration of Claude Fable 5, Gemini's Video Dev Engine, DeepSeek Speeds Up Speculative Decoding
- Introducing Claude Sonnet 5
- The Same TypeScript Costs 73% More Tokens on Claude Than GPT
- Anthropic extends Fable 5 again — and won’t talk about what developers found inside Cursor
- 6 months to live for open models
- Fable 5 Vs Opus 4.8: Outcomes-Based Assessments Are A Massive Warning For Frontier AI Labs
- Grok x Cursor
- Price per 1M tokens is meaningless
- Better Models: Worse Tools
- Fable 5 will default to Opus 4.8 for coding tasks
- Fable is Back: This Safeguard Has Some AI in It!
June 2026
Multiple AI labs release new model variants and agent capabilities Model release
Zhipu releases GLM-5.2 open-weight model achieving performance parity with frontier closed-source models Model release
Anthropic releases Claude Fable 5 model with improved benchmarks and new safety restrictions Model release
Anthropic releases Claude Opus 4.8 with improved agentic capabilities and dynamic workflows Model release
Relationships
Products & technology
- Anthropic develops this model · 15 sources
- Claude Opus 5 derived from this model · 1 source
- Fable 5 integrated with this model · 1 source
- Claude Honeycomb EAP integrated with this model · 1 source
- Princeton deploys this model · 1 source
Competition
- Faraday competes with this model · 1 source