Breaking

'LOOPS.md' Spreads Online; Its Link to Karpathy Stays Unverified

July 1, 2026 at 19:15 EDT

AI Agents
Software Dev & Coding
Foundation Models

A configuration file dubbed "LOOPS.md" is circulating among AI developers, with users claiming it makes Claude "stop giving generic answers" and behave dramatically differently. But the claim that it is the exact file Andrej Karpathy actually uses remains unverified, with no official confirmation.

May 19, 2026 · Anthropic · Pre-training

Karpathy joins Anthropic — and one small file reshapes how Claude codes

After Andrej Karpathy joined Anthropic's pre-training team, a ~65-line coding-behavior file said to be his — "CLAUDE.md / LOOPS.md" — spread among developers, with many reporting Claude's responses "completely changed" just by adding it.

Community-measured error rate

One community measurement reported errors dropping after adding the file.

41%

without the file

→

11%

with CLAUDE.md

Column height ∝ error rate · unofficial community-shared derivative

~65

lines in the core file

guiding principles

persistent "system" file

The four principles

Think Before Coding

State assumptions, ask when ambiguous, surface trade-offs.

Simplicity First

Only the minimal requested code — no speculative features or config.

Surgical Changes

Edit only what the request touches; no unrelated refactoring.

Goal-Driven Execution

Define verifiable success criteria and iterate a verification loop.

The verification loop

Define success criteria

→

Make surgical change

→

Self-check / test

→

Iterate

What developers praise

"The first response completely changed"
Fewer generic answers; work followed their thinking
Better diff quality, less rework
More clarifying questions, self-sustaining test loops

The caveats

Overly cautious — confirms even trivial tasks
Verbose for advanced users
May need merging with project instructions
Unofficial derivative — not released by Anthropic

Continue reading

The rest of this article is for AI News Blitz readers. Choose an option below to keep reading.