Umbriel MCP

{
  "version": "1.14.0",
  "transport": "stdio",
  "identifier": "umbriel",
  "runtimeHint": "bunx",
  "registryType": "npm",
  "environmentVariables": [
    {
      "name": "UMBRIEL_PROFILE",
      "format": "string",
      "default": "safe",
      "description": "Capability profile: 'readonly' (inspect/read only), 'safe' (read + input + window — default), or 'full' (also os + fs tools)."
    },
    {
      "name": "UMBRIEL_OS",
      "format": "string",
      "description": "Set to '1' to allow the 'os' tools (launch_app/run_program/open_path, kill_process, manage_process, control_service, set_env, registry_get/registry_list/registry_set) AND the 'fs' tools (read_file/write_file/list_dir/stat_path/make_dir/copy_file/move_file/delete_file) regardless of profile."
    },
    {
      "name": "UMBRIEL_ALLOW",
      "format": "string",
      "description": "Comma-separated tool names or categories to additionally allow on top of the profile."
    },
    {
      "name": "UMBRIEL_DENY",
      "format": "string",
      "description": "Comma-separated tool names or categories to deny, overriding the profile and UMBRIEL_ALLOW."
    },
    {
      "name": "UMBRIEL_CURSOR",
      "format": "string",
      "description": "Set to 'never' to forbid the real-cursor fallback entirely (strictly cursor-free). By default clicks/drags are cursor-free but fall back to the real hardware cursor when no cursor-free path exists."
    },
    {
      "name": "UMBRIEL_FS_ROOT",
      "format": "string",
      "description": "Sandbox root directory that the fs-category file tools (read_file/write_file/list_dir/stat_path/make_dir/copy_file/move_file/delete_file) are confined to when fs tools are enabled; open_path's path argument is honored too."
    },
    {
      "name": "UMBRIEL_TRACE",
      "format": "string",
      "description": "File path to journal every mutating tool call as JSON Lines (tool, category, masked args, ok, observation); secret-bearing args and values are redacted. Unset = no trace."
    },
    {
      "name": "UMBRIEL_FFI_TRACE",
      "format": "string",
      "description": "File path to a flush-before-call diagnostic journal of every COM vcall (slot, this-pointer, arg count). Each line is written and flushed to the OS BEFORE the native call, so after an uncatchable crash the last line names the faulting call. Has per-call overhead; unset = off. For debugging native faults only."
    },
    {
      "name": "UMBRIEL_AUDIT",
      "format": "string",
      "description": "Controls the default-on stderr audit of mutating tool calls. 'off' is the explicit opt-out (reported at startup); 'verbose' also audits reads."
    },
    {
      "name": "UMBRIEL_REDACT",
      "format": "string",
      "description": "Credential masking (default on). 'off' opts out; a regex value overrides the built-in secret shapes masked in clipboard/env/registry reads and the trace journal."
    }
  ]
}