Anthropic and Google push new models

Anthropic and Google used back-to-back announcements this week to push new model releases deeper into coding, agentic workflows and cybersecurity. Anthropic said on September 1 that Claude Fable 5.1 is generally available, while Claude Mythos 5.1 is limited to trusted-access programs for selected U.S. organizations. Google said on September 2 that it is launching Gemini 3.8 Flash and Gemini 3.8 Flash Cyber as its latest fast-turnaround additions to the Gemini lineup. Together, the releases show model vendors still shipping at a rapid pace while drawing sharper lines around access, safeguards and task-specific packaging. ### Why did Anthropic split the launch between Fable 5.1 and Mythos 5.1? Anthropic said Claude Fable 5.1 and Claude Mythos 5.1 are “the same model” with different levels of safeguards. The company said Fable 5.1 is generally available, while Mythos 5.1 is reserved for trusted access programs and is designed to support work in cybersecurity and the life sciences. The Anthropic release said Fable 5.1 can now be used to identify software vulnerabilities in source code, while its biology safeguards intervene on benign requests 85% less often than the safeguards launched with Fable 5. (anthropic.com) The company said Fable 5.1 still blocks penetration testing, exploit generation and binary-based vulnerability scanning, and routes some dual-use biology and chemistry questions to other Claude models. ### What changed on price and access in Anthropic’s release? Anthropic said Fable 5.1 includes changes on price, data retention and safeguards. Third-party coverage citing Anthropic’s product pages said input and output prices remain $10 per million input tokens and $50 per million output tokens, while cache reads fall to $0.25 per million tokens, a 75% reduction from Fable 5. (anthropic.com) Tbreak reported that Anthropic estimates the lower cache-read price cuts typical token-billed workloads by about 25% and highly agentic work by up to about 45%. Anthropic’s Fable page says Fable 5.1 is available to Pro, Max, Team and Enterprise users and through the Claude Platform, Amazon Web Services, Google Cloud and Microsoft Foundry. ### What is Google packaging into Gemini 3.8 Flash and 3.8 Flash Cyber? (anthropic.com) Google said Gemini 3.8 Flash is built for “agentic workflows,” while Gemini 3.8 Flash Cyber is aimed at cybersecurity use cases. The company described 3.8 Flash Cyber as its “most advanced cyber model” and paired it with a system called CodeMender in its Fairwind Program for trusted partners. (tbreak.com) Google said the new models continue its Flash-series push on efficiency and quality for scaled workflows. In the launch post, the company said Gemini 3.8 Flash is its third Flash release in six weeks, underscoring the cadence at which Google is updating the family. ### Why are both companies talking so much about workflows instead of just model intelligence? (blog.google) Google’s launch post framed Gemini 3.8 Flash around agentic workflows rather than a broad consumer release. Anthropic’s announcement similarly emphasized coding, knowledge work, safeguards and operational features such as pricing and retention. (blog.google) Those details point users toward the surrounding system rather than just the base model. Anthropic is differentiating between open and restricted access through safeguards and deployment rules, while Google is pairing a model with a named cyber program and harness. That suggests buyers evaluating these releases will also be comparing routing, retrieval, testing and workflow controls — an inference based on how both companies described where and how the models are meant to be used. (blog.google) ### Where do these releases go next? Anthropic said Mythos 5.1 is currently available only through trusted access programs, with expansion tied to those controlled channels. Google said Gemini 3.8 Flash Cyber is being offered through Fairwind, its program for trusted partners using cyber defense tools. Anthropic’s Fable 5.1 is already listed across Claude plans, the Claude API and major cloud channels, while Google’s September 2 post positions 3.8 Flash and 3.8 Flash Cyber as the latest entries in a release cycle that has produced three Flash launches in six weeks. (anthropic.com 1) (anthropic.com 2)