Anthropic Launches Claude 5.1, Cuts Cache Fees 75%, Boosts Compliance: what are the key facts?

On September 1, Anthropic released the Fable and Mythos 5.1 models, with the latter restricted to audited institutions.

Anthropic Launches Claude 5.1, Cuts Cache Fees 75%, Boosts Compliance: what are the key facts?

Fable 5.1 significantly outperformed its predecessor and competitor GPT-5.6 in coding and scientific benchmarks.

Anthropic Launches Claude 5.1, Cuts Cache Fees 75%, Boosts Compliance: what are the key facts?

Cache read fees were reduced by 75%, lowering costs for typical workloads by approximately 25% to 45%.

Anthropic Launches Claude 5.1, Cuts Cache Fees 75%, Boosts Compliance: what are the key facts?

The company introduced Enterprise Frontier Safeguards (EFS), allowing customers to fully control data via their own cloud infrastructure.

Anthropic Launches Claude 5.1, Cuts Cache Fees 75%, Boosts Compliance: what are the key facts?

In response to the EU AI Act, new model outputs now include invisible watermarks by default to meet transparency requirements.

Physix Frontier · News Briefing Card (enbrief · Sep 2, 2026)

Anthropic Launches Claude 5.1, Cuts Cache Fees 75%, Boosts Compliance

KEY FACTS

On September 1, Anthropic released the Fable and Mythos 5.1 models, with the latter restricted to audited institutions.
Fable 5.1 significantly outperformed its predecessor and competitor GPT-5.6 in coding and scientific benchmarks.
Cache read fees were reduced by 75%, lowering costs for typical workloads by approximately 25% to 45%.
The company introduced Enterprise Frontier Safeguards (EFS), allowing customers to fully control data via their own cloud infrastructure.
In response to the EU AI Act, new model outputs now include invisible watermarks by default to meet transparency requirements.

KEY DATA

75%Cache Read Reduction

55.8%Terminal-Bench 4.0 Score

$10/millionInput Token Price

PHYSIX OBSERVATION

Anthropic is shifting from a pure performance chase to building an enterprise moat defined by high availability and strict compliance. The steep cut in cache costs directly addresses pain points in agentic applications, while EFS solutions and EU watermarking mechanisms precisely target major clients' anxieties regarding data sovereignty and regulation. This strategy of deeply coupling technical iteration with geopolitical compliance aims to accelerate dominance in the global enterprise market by lowering barriers and eliminating concerns.

Source: enbrief original report ↗