# scopeblind-mcp

Security proxy for stdio MCP servers. It logs tool calls in shadow mode and blocks unauthorized actions under local policies.

- MCP server · `type=mcp` · Claude Code, Codex, Cursor, GitHub Copilot, Windsurf (Devin Desktop), Cline, Zed, Gemini CLI · ★ 11
- Author: tomjwxf
- License: MIT · policy=link-only · description only; the file stays with the author
- Source: https://github.com/tomjwxf/scopeblind-gateway
- Updated: 2026-07-03
- HTML: https://affpapa.org/en/nevibecode/mcp/scopeblind-mcp

## What it does

The gateway runs as a transparent stdio proxy placed between an MCP client and the target server. It inspects incoming `tools/call` JSON-RPC requests. Other messages like `initialize` and notifications pass through without inspection. In the default shadow mode, it only logs decisions to `stderr` with a `[PROTECT_MCP]` tag.

Fine-grained control requires a JSON policy file. You can block dangerous tools outright, enforce rate limits like `5/hour`, and define tier requirements. Running `protect-mcp init` creates local Ed25519 signing keys. Once configured, the proxy saves signed receipts to `.protect-mcp-receipts.jsonl` and exposes them locally at `http://127.0.0.1:9876/receipts`.

By default, all traffic passes. The gateway enforces rules only when launched with the `--enforce` flag alongside a policy file. Standard CLI proxy sessions stay at `unknown` tier unless an integration sets admission state programmatically.

## Requirements
- Needs: Node.js (commands run via npx)

## Install

### Claude Code (native platform)

**Platform CLI**
```bash
claude mcp add scopeblind-mcp -- npx -y scopeblind-mcp
```

### Codex

**Platform CLI**
```bash
codex mcp add scopeblind-mcp -- npx -y scopeblind-mcp
```

### Cursor

**Config file**
File `.cursor/mcp.json`:
```json
{
    "mcpServers": {
        "scopeblind-mcp": {
            "command": "npx",
            "args": [
                "-y",
                "scopeblind-mcp"
            ]
        }
    }
}
```

### GitHub Copilot

**Config file**
File `.vscode/mcp.json`:
```json
{
    "servers": {
        "scopeblind-mcp": {
            "type": "stdio",
            "command": "npx",
            "args": [
                "-y",
                "scopeblind-mcp"
            ]
        }
    }
}
```

### Gemini CLI

**Platform CLI**
```bash
gemini mcp add scopeblind-mcp npx -y scopeblind-mcp
```

## When to use it
- log MCP tool invocations in background shadow mode
- block dangerous operations through policy rules
- enforce rate limits on expensive tool requests
- generate Ed25519 signed receipts for local auditing

## Example prompts
- Run protect-mcp init to generate a config template and Ed25519 signing keys.
- Export an audit bundle by running npx protect-mcp bundle --output audit.json.
- Check gateway stats and recent signed receipts with protect-mcp status.

## Similar
- [Vaara](https://affpapa.org/en/nevibecode/mcp/vaara.md) — MCP server · ★ 15
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- [GateCore Marketplace](https://affpapa.org/en/nevibecode/mcp/gatecore-marketplace.md) — MCP server
- [protect-mcp-setup](https://affpapa.org/en/nevibecode/skills/protect-mcp-setup.md) — skill · 6000 installs
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