I pointed Claude Code at my Obsidian vault, and it became the second brain I never had the discipline to build

The concept of a "second brain" has been around in the productivity space for years, thanks in part to Tiago Forte's book "Building a Second Brain". The idea is to put all of your digital life into one trusted system and let it manage and remember for you.

According to Dev.to, someone experimented with Claude Code, a tool that helps build a second brain, by initially splitting their skills into two files: a short SKILL.md and a reference.md with full original text and history. However, they later undid this split and rebuilt each skill as a single SKILL.md file, moving the history to a separate docs folder.

Opus 5.5, a model that works with Claude apps and Claude Code, has some new features. It can handle long, multi-part work better than its predecessor, Opus 5, and can run coding tasks for hours with little oversight if given a clear finish line. Additionally, Opus 5.5 always thinks before it replies and decides how much thinking to do, so users don't need to ask it to think carefully.

Brief written by urgent.news from XDA Developers, Dev.to, Hacker News Best, Hacker News — 4 reports on this story. Machine-written — may contain errors; check the original before relying on it.