Anthropic accidentally published Claude Code's full source code to npm

Anthropic, disclosed 31 Mar 2026. Leaky AI product Data exposed Medium

A packaging mistake shipped a complete source map inside a public Claude Code release on npm, exposing about 512,000 lines of the agent's code, including its permission system and unreleased features. Anthropic confirmed it was human error; the code was mirrored widely within hours.

Disclosed

31 Mar 2026

Organization

Anthropic

Vendor

Anthropic

Product

Claude Code

Type of AI

Coding assistant

How it happened

Leaky AI product: Accidental publication

Harm

Data exposed

Data involved

Source code

Reach

One organization

Severity

Medium

Model at fault

No

Status

Confirmed

Sources

1. https://thehackernews.com/2026/04/claude-code-tleaked-via-npm-packaging.html
2. https://venturebeat.com/technology/claude-codes-source-code-appears-to-have-leaked-heres-what-we-know
3. https://cybernews.com/security/anthropic-claude-code-source-leak/