Blindfold: A Plugin That Prevents Claude Code from Reading Your .env Files

What Blindfold Does

Blindfold is a security plugin designed to prevent Claude Code from reading and exposing secrets from .env files. The tool addresses a documented issue where Claude Code reads .env files without explicit permission and can inadvertently commit secrets to repositories.

How It Works

Blindfold keeps actual secret values in your OS keychain rather than exposing them to Claude. Claude only sees placeholders like {{STRIPE_KEY}}. When a command needs the real value, a wrapper script injects it in a subprocess and scrubs it from the output before Claude reads it back.

The plugin includes hooks that block commands if Claude tries to read the keychain directly or use cat on your .env file, preventing the commands from executing.

The Problem It Solves

According to the source, Claude Code reads .env files when debugging and can commit real secret values to files like env.example. GitGuardian's 2026 report indicates Claude Code co-authored commits leak secrets at 2x the baseline rate, with 1.27 million AI-service secrets leaked on GitHub last year alone (an 81% increase from the previous year).

The issue is that once a secret enters Claude's context window, it becomes "fair game for every tool call, every suggestion, every commit for the rest of the conversation."

Installation

Two commands to install:

/plugin marketplace add thesaadmirza/blindfold
/plugin install blindfold@blindfold

Verification

The creator tested the plugin by storing a GitLab token through it and then asking Claude: "what are the last three characters of my token?" Claude had no idea because the actual value never entered the conversation context.