Claude formalizes Fermat's Last Theorem while Fable 5.1 cuts costs to the bone.

From the editor

Two themes dominate today. First, capability: a machine-checked proof of Fermat's Last Theorem is not a party trick. It signals that AI is now a serious peer in formal mathematics, not just a coding assistant. Second, economics: Fable 5.1's 75% caching cut, the Spotify Method achieving 90% token savings, and cheaper agentic workflows all point to a deliberate race to the cost floor. Anthropic is compressing the price of intelligence while simultaneously expanding what that intelligence can do. Both trends compound.

TL;DR

Claude formally proves Fermat's Last Theorem in Lean, a genuine mathematical milestone.
Fable 5.1 cuts caching costs 75%; community finds another 90% savings on top.
Astra reasoning without chain of thought raises real questions about how frontier models think.

8 curated itemsscroll for the brief

Releases

What shipped · 4 items

Anthropic's AI formalizes Fermat's Last Theorem in Lean

Anthropic's AI produced a machine-checked formal proof of Fermat's Last Theorem in Lean, five times the size of Mathlib. A landmark result for AI-assisted mathematics.

dev.to

Claude Fable 5.1 Is Here: 75% Cheaper Caching, Insane Agent Benchmarks

Claude Fable 5.1 slashes context caching costs by 75% and posts impressive agent benchmark scores. Worth watching token consumption when running long agentic workflows.

dev.to

v2.1.267

Claude Code v2.1.267 ships bug fixes covering settings, mobile experience, workflow, and security improvements.

Claude Code

inspector: 2.6.0

MCP Inspector 2.6.0 adds OAuth support, a skills extension, and various bug fixes for developers building on the Model Context Protocol.

MCP

Tools

Worth a look · 1 item

show LW: programmatic internet research, scry.io

Scry.io lets AI agents query 500TB of internet data using a SQL-like interface, making large-scale programmatic web research practical without custom scrapers.

LessWrong

Tips

Actionable craft · 1 item

Cut your Claude Code cost by 90% using the Spotify Method

A community-shared technique using what is dubbed the Spotify Method to reduce Claude Code token spend by up to 90% through smarter plugin and caching strategies.

r/ClaudeAI

Reading

Long-form signal · 1 item

Astra can do a concerning amount with no chain of thought

New analysis shows Astra performs 8.6x better than competing models on tasks requiring no chain of thought, suggesting it may be using fundamentally different cognitive mechanisms rather than explicit step-by-step reasoning.

LessWrong

Discussions

Where it heats up · 1 item

Cut your Claude Code cost by 90% using the Spotify Method

Reddit thread where developers share a cost-cutting technique for Claude Code, reportedly achieving up to 90% token savings using a method borrowed from Spotify's plugin infrastructure.

r/ClaudeAI

Always at hand

Reference links you keep open