zn-gate for Claude Code

Install the zn-gate plugin for Claude Code: it blocks reads of .env files with real values, scrubs secrets from tool output and blocks secrets pasted into prompts.

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You need Node.js 18 or later, Git and Claude Code 2.1.295 or later. Paste each line in a terminal and press Enter after each one:

claude plugin marketplace add usezn/zn
claude plugin install zn-gate@usezn

Then start a new Claude Code session.

Already ran zn hooks install claude-code before? Run zn hooks uninstall claude-code first, otherwise both sets of hooks run.

What you get

  • Claude Code is blocked from reading .env files with real values and credential files.
  • Secrets in what its tools return are replaced with markers or redacted before the model sees them.
  • A secret pasted into a prompt is blocked.
  • Claude can check untrusted text for prompt injection.

Not covered: Claude Code sessions in the cloud, Cowork and chat.

If the zn hook cannot run (for example, node is missing), tool calls run unchecked and prompts are blocked.

Keep your .env values in the vault

The agent cannot read .env files with real values. Move the values into zn-gate's encrypted vault, and the file keeps markers such as __ZN_STRIPE_KEY__:

npx -y zn-gate unlock            # creates the vault the first time
npx -y zn-gate env shadow .env

After this your own app also reads the markers: start it with zn-gate's run command once you allow it. env shadow tells you how to undo it. More: the vault.

Check that it works

In a new terminal, run npx -y zn-gate check. It should show OK for Claude Code. What the output means.

On Windows PowerShell, if npm or npx says "running scripts is disabled on this system", use npx.cmd instead of npx: see Install.