@byzantinelabs/mcp-server

Secure stdio bridge for the Byzantine Systolic MCP endpoint.

The package runs locally as a process-spawned MCP server and proxies tool calls to a remote Streamable HTTP MCP endpoint such as:

https://YOUR_DEPLOYMENT/api/mcp

Why this exists

This repo's MCP implementation lives in the web app as an HTTP endpoint. Many MCP clients still expect a local stdio process. This package bridges the two without copying GCP credentials or TPU control logic onto every user machine.

Usage

SYSTOLIC_MCP_API_KEY=YOUR_MCP_API_KEY \
npx -y @byzantinelabs/mcp-server --url https://YOUR_DEPLOYMENT/api/mcp

Example client config:

{
  "mcpServers": {
    "systolic": {
      "command": "npx",
      "args": ["-y", "@byzantinelabs/mcp-server", "--url", "https://YOUR_DEPLOYMENT/api/mcp"],
      "env": {
        "SYSTOLIC_MCP_API_KEY": "YOUR_MCP_API_KEY"
      }
    }
  }
}

Security defaults

• Refuses plain HTTP by default.
• Only allows HTTP when --allow-http is set and the host is loopback.
• Requires the API key to come from an environment variable, not a CLI flag.
• Rejects URLs with embedded credentials.
• Fails closed if the remote endpoint does not advertise MCP tool support.
• Proxies only MCP tool methods. It does not expose arbitrary shell or network access locally.

License

This package is proprietary. It is provided for download, installation, and use with authorized Byzantine Labs services only. See LICENSE.

Configuration

• --url or SYSTOLIC_MCP_URL: remote MCP endpoint URL.
• --api-key-env: environment variable name that contains the API key. Default: SYSTOLIC_MCP_API_KEY.
• --allow-http: allow http:// only for loopback development endpoints.

Publishing

This package name requires control of the npm scope @byzantinelabs.

Configure npm trusted publishing for the GitHub repository and this workflow path first:

• Repository: john7rho/byzantine-systolic
• Workflow filename: publish-mcp-server.yml

Once trusted publishing is configured in npm, publish by running the GitHub Actions workflow manually or locally with:

pnpm --filter @byzantinelabs/mcp-server publish --access public

Recommended local preflight:

pnpm --filter @byzantinelabs/mcp-server build
pnpm --filter @byzantinelabs/mcp-server smoke
pnpm --filter @byzantinelabs/mcp-server pack:dry-run