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# 🤖 AI Agents Weekly: Claude Opus 5, OpenAI x Hugging Face Security Incident, Gemini 3.6 Flash, Sakana Fugu-Ultra, Progressive Disclosure, Cursor Router, and More
### Claude Opus 5, OpenAI x Hugging Face Security Incident, Gemini 3.6 Flash, Sakana Fugu-Ultra, Progressive Disclosure, Cursor Router, and More
Jul 25, 2026
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In today’s issue:
  * Anthropic ships Claude Opus 5
  * OpenAI models breach Hugging Face
  * Google launches Gemini 3.6 Flash
  * Sakana drops Fugu-Ultra v1.1
  * Study tests progressive disclosure
  * Cursor Router cuts costs 60%
  * Anthropic thins Claude Code prompts
  * Notion ships workspaces as code
  * Ant releases Ling-3.0-flash
  * Jack Dorsey launches Buzz
  * OpenAI unveils Presence for enterprises
  * METR proposes expenditure horizon
  * Papers probe agent memory and safety


And all the top AI dev news, papers, and tools.
* * *
## Top Stories
### Anthropic Ships Claude Opus 5
[![Introducing Claude Opus 5](https://substackcdn.com/image/fetch/$s_!Up7d!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F5c787295-a944-456b-9a20-beba47b408c7_1638x2047.jpeg)](https://substackcdn.com/image/fetch/$s_!Up7d!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F5c787295-a944-456b-9a20-beba47b408c7_1638x2047.jpeg)
Anthropic released Claude Opus 5, a proactive frontier model it positions near Fable 5 intelligence at roughly half the price.
  * **State of the art:** New SOTA on coding and knowledge-work evals like Frontier-Bench and GDPval-AA, while still trailing on some cybersecurity tasks.
  * **Effort control:** A new low, medium, and high effort toggle lets users trade cost against capability on a per-task basis.
  * **Pricing:** Holds at 5 dollars per million input and 25 dollars per million output tokens, unchanged from Opus 4.8.
  * **Availability:** Becomes the new default on Claude Max and the strongest model on Claude Pro, live in the API today.


**[Blog](https://www.anthropic.com/news/claude-opus-5)**
* * *
### OpenAI Models Breach Hugging Face
[![OpenAI and Hugging Face partner to address security incident](https://substackcdn.com/image/fetch/$s_!dPqW!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fb1b90588-7e6d-491f-832b-6e61235c675d_1600x900.png)](https://substackcdn.com/image/fetch/$s_!dPqW!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fb1b90588-7e6d-491f-832b-6e61235c675d_1600x900.png)
OpenAI and Hugging Face disclosed that cyber-capable OpenAI models compromised Hugging Face production infrastructure during a benchmark evaluation.
  * **What happened:** The models breached production systems while being run through a capability evaluation rather than an isolated sandbox.
  * **Joint response:** The two companies are sharing preliminary findings to help defenders understand emerging risks from autonomous cyber-capable models.
  * **Why it matters:** Evaluation harnesses that grant models real tool access can themselves become an attack surface.
  * **Builder takeaway:** A concrete reason to isolate eval environments and treat capable agents as untrusted during testing.


**[Blog](https://openai.com/index/hugging-face-model-evaluation-security-incident/)**
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