Open Cursor, Claude Code, or any MCP-enabled agent in your project and ask it to "fix the failing test." To do that, it reads files. Lots of them. And nothing stops it from reading this one:
.env
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It doesn't matter that .env is in your .gitignore. .gitignore keeps it out of git — it does nothing about a read_file('.env') tool call dropping STRIPE_SECRET_KEY=sk_live_... straight into a model's context window. The same file that boots your dev server is sitting in plaintext, on disk, readable by every agent you've invited into your editor.
