MCP Sidecar MCP Server

What the code does

We read the source, 5 d ago · rules 995398eba69f

What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.

  execFileSync(binPath, process.argv.slice(2), { stdio: "inherit" });

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Connect this server

This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.

claude mcp add mcp-sidecar -- npx -y mcp-sidecar

{
  "mcpServers": {
    "mcp-sidecar": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-sidecar"
      ]
    }
  }
}

[mcp_servers.mcp-sidecar]
command = "npx"
args = ["-y", "mcp-sidecar"]

{
  "mcpServers": {
    "mcp-sidecar": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-sidecar"
      ]
    }
  }
}

{
  "servers": {
    "mcp-sidecar": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mcp-sidecar"
      ]
    }
  }
}

Optional settings from the registry entry, left out of the block above: SIDECAR_MAX_PROCESSES (Maximum number of concurrent managed processes (default: 10)), SIDECAR_BUFFER_SIZE (Output buffer size per stream in bytes (default: 1048576)), SIDECAR_KILL_TIMEOUT (Milliseconds to wait between graceful and forced termination (default: 5000)), SIDECAR_CLEANUP_AFTER (Seconds before exited processes are auto-removed. 0 disables cleanup (default: 1800)), SIDECAR_MAX_OUTPUT_SIZE (Global cap on bytes returned by the output tool. 0 means unlimited (default: 0)), SIDECAR_ALLOWED_EXECUTABLES (Comma-separated allowlist of executable names. When set, enables security mode with direct exec (no shell). Unset means security disabled), SIDECAR_BLOCKED_PATTERNS (Comma-separated regex patterns to reject in commands. Only applies when security is enabled), SIDECAR_AUDIT_LOG (Audit log destination. 'true' writes to cwd, 'temp' writes to OS temp dir, or a directory path. Unset disables audit logging).