diff --git a/EvoScientist/EvoScientist.py b/EvoScientist/EvoScientist.py
index 40cb366..7c4bb51 100644
--- a/EvoScientist/EvoScientist.py
+++ b/EvoScientist/EvoScientist.py
@@ -274,11 +274,16 @@ def _load_mcp_tools_cached(on_progress=None) -> dict[str, list]:
 
 def _configured_system_prompt(cfg) -> str:
     memory_controls = MemoryControls.from_config(cfg)
+    # In dangerous mode the agent works on the real filesystem; give it the real
+    # cwd so it can use absolute paths instead of the virtual `/` workspace root.
+    real_cwd = str(_paths_mod.resolve_virtual_path("/")) if cfg.dangerous_mode else None
     return get_system_prompt(
         enable_observation_memory=memory_controls.observations_enabled,
         enable_observation_writes=memory_controls.observation_tool_enabled(
             MemoryObservationTarget.AGENT
         ),
+        dangerous=cfg.dangerous_mode,
+        cwd=real_cwd,
     )
 
 
@@ -600,10 +605,13 @@ def _get_default_backend():
     user_skills_dir = str(_paths_mod.USER_SKILLS_DIR)
     global_skills_dir = str(_paths_mod.GLOBAL_SKILLS_DIR)
 
+    # Dangerous mode opens the workspace (`/`) route to the real filesystem;
+    # the /skills/ and /memories/ routes stay confined (virtual_mode=True).
     ws_backend = CustomSandboxBackend(
         root_dir=workspace_dir,
         virtual_mode=True,
         timeout=cfg.sandbox_execute_timeout,
+        dangerous=cfg.dangerous_mode,
     )
     sk_backend = MergedSkillsBackend(
         primary_dir=user_skills_dir,
@@ -919,6 +927,7 @@ def create_cli_agent(
         root_dir=workspace_dir,
         virtual_mode=True,
         timeout=cfg.sandbox_execute_timeout,
+        dangerous=cfg.dangerous_mode,
     )
     sk_backend = MergedSkillsBackend(
         primary_dir=_usr_skills_dir,
diff --git a/EvoScientist/backends.py b/EvoScientist/backends.py
index 2125bc5..b17acde 100644
--- a/EvoScientist/backends.py
+++ b/EvoScientist/backends.py
@@ -43,10 +43,14 @@ _SYSTEM_PATH_PREFIXES = (
     "/root/",
 )
 
-# Dangerous patterns that could escape the workspace
-BLOCKED_PATTERNS = [
+# Path-confinement patterns: keep the agent inside the workspace. These are
+# bypassed in dangerous mode (real-filesystem access).
+_PATH_PATTERNS = [
     r"~/",  # home directory
     r"\bcd\s+/",  # cd to absolute path
+]
+# Destructive patterns: catastrophic regardless of mode — always enforced.
+_DESTRUCTIVE_PATTERNS = [
     r"\brm\s+-rf\s+/",  # rm -rf with absolute path
 ]
 
@@ -499,6 +503,8 @@ def _extract_all_paths(
 def validate_command(
     command: str,
     allow_prefixes: tuple[str, ...] = (),
+    *,
+    dangerous: bool = False,
 ) -> str | None:
     """
     Validate a shell command for safety.
@@ -507,20 +513,35 @@ def validate_command(
         command: Shell command string.
         allow_prefixes: Absolute path prefixes exempt from the system-path
             block list (matching rules in ``_is_under_allowed_prefix``).
+        dangerous: When True (real-filesystem mode), skip the path-confinement
+            checks (``..`` traversal, ``~/``/``cd /`` patterns, absolute system
+            paths). Privileged commands (:data:`BLOCKED_COMMANDS`) and
+            catastrophic patterns (:data:`_DESTRUCTIVE_PATTERNS`) are still
+            enforced.
 
     Returns:
         None if command is safe, error message string if blocked.
     """
-    # Check for '..' path traversal as a path component
-    if _has_traversal_component(command):
-        return (
-            "Command blocked: contains '..' path traversal. "
-            "All commands must operate within the workspace directory. "
-            "Use relative paths (e.g., './file.py') instead."
-        )
+    # Path-confinement checks — skipped in dangerous mode.
+    if not dangerous:
+        # Check for '..' path traversal as a path component
+        if _has_traversal_component(command):
+            return (
+                "Command blocked: contains '..' path traversal. "
+                "All commands must operate within the workspace directory. "
+                "Use relative paths (e.g., './file.py') instead."
+            )
 
-    # Check for dangerous patterns
-    for pattern in BLOCKED_PATTERNS:
+        for pattern in _PATH_PATTERNS:
+            if re.search(pattern, command):
+                return (
+                    f"Command blocked: contains forbidden pattern '{pattern}'. "
+                    f"All commands must operate within the workspace directory. "
+                    f"Use relative paths (e.g., './file.py') instead."
+                )
+
+    # Catastrophic patterns (e.g. `rm -rf /`) — always enforced.
+    for pattern in _DESTRUCTIVE_PATTERNS:
         if re.search(pattern, command):
             return (
                 f"Command blocked: contains forbidden pattern '{pattern}'. "
@@ -528,7 +549,7 @@ def validate_command(
                 f"Use relative paths (e.g., './file.py') instead."
             )
 
-    # Check for dangerous commands (pipeline-aware)
+    # Check for dangerous commands (pipeline-aware) — always enforced.
     for base_cmd in _split_shell_commands(command):
         if base_cmd in BLOCKED_COMMANDS:
             return (
@@ -536,16 +557,17 @@ def validate_command(
                 f"Only standard development commands are permitted."
             )
 
-    # Check for absolute system paths (including inside quoted strings).
-    # This catches attacks like: python -c "os.remove('/Users/foo/file')"
-    escaped_paths = _extract_all_paths(command, allow_prefixes=allow_prefixes)
-    if escaped_paths:
-        path_sample = escaped_paths[0]
-        return (
-            f"Command blocked: contains absolute system path '{path_sample}'. "
-            f"All file operations must use relative paths within the workspace. "
-            f"Use relative paths (e.g., './file.py') instead."
-        )
+    # Absolute-system-path check — skipped in dangerous mode.
+    # Catches attacks like: python -c "os.remove('/Users/foo/file')"
+    if not dangerous:
+        escaped_paths = _extract_all_paths(command, allow_prefixes=allow_prefixes)
+        if escaped_paths:
+            path_sample = escaped_paths[0]
+            return (
+                f"Command blocked: contains absolute system path '{path_sample}'. "
+                f"All file operations must use relative paths within the workspace. "
+                f"Use relative paths (e.g., './file.py') instead."
+            )
 
     return None
 
@@ -828,7 +850,7 @@ class MergedSkillsBackend(BackendProtocol):
 
 
 def prepare_sandbox_command(
-    command: str, cwd: str | Path, *, virtual_mode: bool = True
+    command: str, cwd: str | Path, *, virtual_mode: bool = True, dangerous: bool = False
 ) -> tuple[str, str | None]:
     """Normalize workspace paths in ``command`` and validate it for the sandbox.
 
@@ -849,10 +871,13 @@ def prepare_sandbox_command(
     # Replace literal workspace-root absolute paths with ./ after SSH masking so
     # remote paths that happen to contain the local cwd are preserved, and before
     # validation so local workspace paths are sanitized before the system-path
-    # check fires.
-    ws = cwd_str + "/"
-    if ws in command:
-        command = command.replace(ws, "./")
+    # check fires. Skipped in dangerous mode: there is no virtual workspace, the
+    # agent uses real absolute paths, and rewriting would corrupt any argument
+    # (echo text, grep/git pattern) that merely contains the cwd string.
+    if not dangerous:
+        ws = cwd_str + "/"
+        if ws in command:
+            command = command.replace(ws, "./")
     if virtual_mode:
         command = convert_virtual_paths_in_command(
             command=command,
@@ -866,7 +891,9 @@ def prepare_sandbox_command(
         str(paths.MEMORIES_DIR),
         str(_BUILTIN_SKILLS_DIR),
     )
-    error = validate_command(command, allow_prefixes=allow_prefixes)
+    error = validate_command(
+        command, allow_prefixes=allow_prefixes, dangerous=dangerous
+    )
     if error:
         return command, error
     return _restore_spans(command, ssh_replacements), None
@@ -893,6 +920,7 @@ class CustomSandboxBackend(LocalShellBackend):
         max_output_bytes: int = 100_000,
         env: dict[str, str] | None = None,
         inherit_env: bool = True,
+        dangerous: bool = False,
     ):
         """
         Initialize custom sandbox backend.
@@ -904,7 +932,16 @@ class CustomSandboxBackend(LocalShellBackend):
             max_output_bytes: Max output size before truncation (default 100KB)
             env: Extra environment variables for subprocess
             inherit_env: Whether to inherit parent process env (default True)
+            dangerous: Real-filesystem mode — the agent operates on real absolute
+                paths anywhere on disk (no workspace confinement). Forces
+                ``virtual_mode=False`` and relaxes path validation while keeping
+                the privileged-command blocklist. Defaults to False.
         """
+        self._dangerous = dangerous
+        if dangerous:
+            # Real paths require the legacy (non-virtual) resolution path so the
+            # parent backend returns absolute paths as-is.
+            virtual_mode = False
         super().__init__(
             root_dir=root_dir,
             virtual_mode=virtual_mode,
@@ -927,7 +964,13 @@ class CustomSandboxBackend(LocalShellBackend):
           2. /<ws_name>/file.py            → /file.py
           3. /Users/name/.../<ws_name>/f   → /f  (strip at LAST <ws_name>/)
           4. /Users/name/file.py           → /file.py (keep basename)
+
+        In dangerous (real-filesystem) mode, skip all rewriting and let the
+        parent resolve real absolute paths as-is.
         """
+        if self._dangerous:
+            return super()._resolve_path(key)
+
         cwd_str = str(self.cwd).rstrip("/")
         ws_name = Path(cwd_str).name  # e.g. "workspace", "my-project"
 
@@ -976,7 +1019,7 @@ class CustomSandboxBackend(LocalShellBackend):
         Then delegates to LocalShellBackend.execute() for actual execution.
         """
         command, error = prepare_sandbox_command(
-            command, self.cwd, virtual_mode=self.virtual_mode
+            command, self.cwd, virtual_mode=self.virtual_mode, dangerous=self._dangerous
         )
         if error:
             return ExecuteResponse(output=error, exit_code=1, truncated=False)
@@ -988,7 +1031,10 @@ class CustomSandboxBackend(LocalShellBackend):
         if response.exit_code == 124:
             cmd_words = command.split()
             grep_hint = cmd_words[0] if cmd_words else "process"
-            bg_cmd = f'{command} > /output.log 2>&1 & echo "PID: $!"'
+            # In dangerous mode `/` is the host root; use a workspace-relative
+            # log path so the suggested command doesn't fail or write to `/`.
+            output_log = "./output.log" if self._dangerous else "/output.log"
+            bg_cmd = f'{command} > {output_log} 2>&1 & echo "PID: $!"'
             response = ExecuteResponse(
                 output=(
                     f"{response.output}\n\n"
@@ -998,7 +1044,7 @@ class CustomSandboxBackend(LocalShellBackend):
                     f"  2. Runs indefinitely? Run it in the background and keep the PID:\n"
                     f"       {bg_cmd}\n"
                     f"     Check: ps -p <PID>  (or: ps aux | grep {grep_hint})  ·  "
-                    f"Read: cat /output.log  ·  Stop: kill <PID>"
+                    f"Read: cat {output_log}  ·  Stop: kill <PID>"
                 ),
                 exit_code=response.exit_code,
                 truncated=response.truncated,
diff --git a/EvoScientist/cli/_constants.py b/EvoScientist/cli/_constants.py
index 37501fa..b72bf9d 100644
--- a/EvoScientist/cli/_constants.py
+++ b/EvoScientist/cli/_constants.py
@@ -11,6 +11,13 @@ def _agent_name() -> str:
     return AGENT_NAME
 
 
+# Dangerous-mode warning banner — shared by Rich CLI, Textual TUI, and serve so
+# the wording never drifts. Label is rendered white-on-red, message in red.
+DANGEROUS_BANNER_LABEL = "DANGEROUS MODE"
+DANGEROUS_BANNER_MESSAGE = (
+    "Real-filesystem access • the agent can read/write/delete anywhere."
+)
+
 WELCOME_SLOGANS = [
     "Ready for vibe research? What do you want cooking?",
     "Science doesn't sleep. Neither do your sub-agents.",
diff --git a/EvoScientist/cli/commands.py b/EvoScientist/cli/commands.py
index d277d21..3dae5c8 100644
--- a/EvoScientist/cli/commands.py
+++ b/EvoScientist/cli/commands.py
@@ -1322,6 +1322,11 @@ def serve(
         "--ask-user",
         help="Enable agent to ask clarifying questions about your research preferences",
     ),
+    dangerous: bool = typer.Option(
+        False,
+        "--dangerous",
+        help="DANGEROUS: real-filesystem access (no workspace confinement); implies --auto-approve",
+    ),
     debug: bool = typer.Option(
         False,
         "--debug",
@@ -1344,6 +1349,8 @@ def serve(
         cli_overrides["enable_ask_user"] = False
     elif ask_user:
         cli_overrides["enable_ask_user"] = True
+    if dangerous:
+        cli_overrides["dangerous_mode"] = True
     if debug:
         cli_overrides["log_level"] = "DEBUG"
         cli_overrides["channel_debug_tracing"] = True
@@ -1390,6 +1397,13 @@ def serve(
     # async sub-agents inherit the CLI's workspace via EVOSCIENTIST_WORKSPACE_DIR).
     _ensure_async_subagent_server(config, workspace_dir=ws)
 
+    if config.dangerous_mode:
+        from ._constants import DANGEROUS_BANNER_LABEL, DANGEROUS_BANNER_MESSAGE
+
+        console.print(
+            f"[bold white on red] ⚠ {DANGEROUS_BANNER_LABEL} [/bold white on red] "
+            f"[bold red]{DANGEROUS_BANNER_MESSAGE}[/bold red]"
+        )
     console.print("[dim]Loading agent...[/dim]")
     agent = _load_agent(workspace_dir=ws, config=config)
     from ..sessions import generate_thread_id
@@ -1964,6 +1978,11 @@ def _main_callback(
         "--ask-user",
         help="Enable agent to ask clarifying questions about your research preferences",
     ),
+    dangerous: bool = typer.Option(
+        False,
+        "--dangerous",
+        help="DANGEROUS: real-filesystem access (no workspace confinement); implies --auto-approve",
+    ),
     auth_mode: str | None = typer.Option(
         None,
         "--auth-mode",
@@ -2001,6 +2020,8 @@ def _main_callback(
         cli_overrides["enable_ask_user"] = False
     elif ask_user:
         cli_overrides["enable_ask_user"] = True
+    if dangerous:
+        cli_overrides["dangerous_mode"] = True
     if auth_mode:
         if auth_mode not in ("api_key", "oauth"):
             raise typer.BadParameter("--auth-mode must be 'api_key' or 'oauth'")
diff --git a/EvoScientist/cli/interactive.py b/EvoScientist/cli/interactive.py
index f8bc1a4..860db78 100644
--- a/EvoScientist/cli/interactive.py
+++ b/EvoScientist/cli/interactive.py
@@ -44,7 +44,14 @@ from ..sessions import (
 from ..stream.console import console
 from ..stream.display import _fix_markdown_heading_spacing
 from ._agent_loader import BackgroundAgentLoader, MCPProgressTracker
-from ._constants import LOGO_GRADIENT, LOGO_LINES, WELCOME_SLOGANS, build_metadata
+from ._constants import (
+    DANGEROUS_BANNER_LABEL,
+    DANGEROUS_BANNER_MESSAGE,
+    LOGO_GRADIENT,
+    LOGO_LINES,
+    WELCOME_SLOGANS,
+    build_metadata,
+)
 from .agent import _create_session_workspace, _load_agent, _shorten_path
 from .channel import (
     ChannelMessage,
@@ -141,6 +148,22 @@ def print_banner(
     info.append(" \u2022 Ctrl+C ", style="#ffe082")
     info.append("interrupt", style="#ffe082 bold")
     console.print(info)
+    print_dangerous_warning()
+
+
+def print_dangerous_warning() -> None:
+    """Print an unmissable warning when dangerous (real-filesystem) mode is on."""
+    try:
+        from ..config import get_effective_config
+
+        if not get_effective_config().dangerous_mode:
+            return
+    except Exception:
+        return
+    warn = Text()
+    warn.append(f"\n  \u26a0 {DANGEROUS_BANNER_LABEL}", style="bold white on red")
+    warn.append(f"  {DANGEROUS_BANNER_MESSAGE}", style="bold red")
+    console.print(warn)
 
 
 # =============================================================================
diff --git a/EvoScientist/cli/tui_interactive.py b/EvoScientist/cli/tui_interactive.py
index ba50809..8ccddb3 100644
--- a/EvoScientist/cli/tui_interactive.py
+++ b/EvoScientist/cli/tui_interactive.py
@@ -36,7 +36,14 @@ from ..sessions import (
 from ..stream.events import stream_agent_events
 from ..stream.state import ResearchPhase, StreamState
 from ._agent_loader import BackgroundAgentLoader, MCPProgressTracker
-from ._constants import LOGO_GRADIENT, LOGO_LINES, WELCOME_SLOGANS, build_metadata
+from ._constants import (
+    DANGEROUS_BANNER_LABEL,
+    DANGEROUS_BANNER_MESSAGE,
+    LOGO_GRADIENT,
+    LOGO_LINES,
+    WELCOME_SLOGANS,
+    build_metadata,
+)
 from .channel import (
     ChannelMessage,
     _auto_start_channel,
@@ -139,6 +146,16 @@ def _build_welcome_banner(
     info.append("@ files", style="#ffe082 bold")
     info.append(" \u2022 Ctrl+C ", style="#ffe082")
     info.append("interrupt", style="#ffe082 bold")
+    try:
+        from ..config import get_effective_config
+
+        if get_effective_config().dangerous_mode:
+            info.append(
+                f"\n  \u26a0 {DANGEROUS_BANNER_LABEL}", style="bold white on red"
+            )
+            info.append(f"  {DANGEROUS_BANNER_MESSAGE}", style="bold red")
+    except Exception:
+        pass
     banner.append_text(info)
 
     slogan = Text(f"\n  {random.choice(WELCOME_SLOGANS)}", style="dim italic")
diff --git a/EvoScientist/config/settings.py b/EvoScientist/config/settings.py
index 1d5b589..9ca2dba 100644
--- a/EvoScientist/config/settings.py
+++ b/EvoScientist/config/settings.py
@@ -332,6 +332,11 @@ class EvoScientistConfig:
     auto_mode: bool = False  # Run unattended: imply auto_approve and disable ask_user
     shell_allow_list: str = ""  # Comma-separated shell command prefixes to auto-approve
 
+    # Dangerous mode: real-filesystem access (no workspace confinement). The agent
+    # operates on real absolute paths anywhere on disk; the privileged-command
+    # blocklist (sudo/chmod/dd/...) still applies. Implies auto_approve.
+    dangerous_mode: bool = False
+
     # Agent features
     enable_ask_user: bool = True  # Enable ask_user tool for agent-initiated questions
 
@@ -386,6 +391,12 @@ class EvoScientistConfig:
             )
             self.sandbox_execute_timeout = 300
 
+        # Dangerous mode implies auto_approve regardless of source (CLI, env,
+        # config file). Mirrors how auto_mode implies auto_approve — done here so
+        # the coupling holds even when dangerous_mode is set via `config set`.
+        if self.dangerous_mode:
+            self.auto_approve = True
+
         try:
             writer = MemoryObservationWriter(
                 str(self.memory_observation_writer).strip().lower()
@@ -636,6 +647,7 @@ _ENV_MAPPINGS = {
     "openrouter_anthropic_prompt_cache": (
         "EVOSCIENTIST_OPENROUTER_ANTHROPIC_PROMPT_CACHE"
     ),
+    "dangerous_mode": "EVOSCIENTIST_DANGEROUS_MODE",
     "channel_debug_tracing": "EVOSCIENTIST_CHANNEL_DEBUG_TRACING",
     "ccproxy_port": "EVOSCIENTIST_CCPROXY_PORT",
     "use_responses_api": "EVOSCIENTIST_USE_RESPONSES_API",
@@ -761,6 +773,16 @@ def apply_config_to_env(config: EvoScientistConfig) -> None:
         "EVOSCIENTIST_OPENROUTER_ANTHROPIC_PROMPT_CACHE"
     ):
         os.environ["EVOSCIENTIST_OPENROUTER_ANTHROPIC_PROMPT_CACHE"] = "true"
+    # Round-trip dangerous_mode to env so it survives a fresh get_effective_config()
+    # (warning banner, run_in_background) and is inherited by the langgraph dev
+    # subprocess — otherwise a --dangerous CLI flag (not persisted to file/env)
+    # is invisible to those consumers while the backend is already unconfined.
+    # Bidirectional: clear it when off so a re-apply with a lower config (or a
+    # stale value) can't leave the process stuck in dangerous mode.
+    if config.dangerous_mode:
+        os.environ["EVOSCIENTIST_DANGEROUS_MODE"] = "true"
+    else:
+        os.environ.pop("EVOSCIENTIST_DANGEROUS_MODE", None)
     if config.use_responses_api and not os.environ.get(
         "EVOSCIENTIST_USE_RESPONSES_API"
     ):
diff --git a/EvoScientist/deploy/server.py b/EvoScientist/deploy/server.py
index 1c9a862..07a246a 100644
--- a/EvoScientist/deploy/server.py
+++ b/EvoScientist/deploy/server.py
@@ -144,6 +144,16 @@ def deploy(
             border_style="cyan",
         )
     )
+    if config.dangerous_mode:
+        from ..cli._constants import (
+            DANGEROUS_BANNER_LABEL,
+            DANGEROUS_BANNER_MESSAGE,
+        )
+
+        console.print(
+            f"[bold white on red] ⚠ {DANGEROUS_BANNER_LABEL} [/bold white on red] "
+            f"[bold red]{DANGEROUS_BANNER_MESSAGE}[/bold red]"
+        )
 
     # 6. ccproxy lifecycle (only if any provider uses OAuth)
     _ccproxy_proc = None
diff --git a/EvoScientist/middleware/background.py b/EvoScientist/middleware/background.py
index 9fda1ab..d1c6ee6 100644
--- a/EvoScientist/middleware/background.py
+++ b/EvoScientist/middleware/background.py
@@ -75,9 +75,19 @@ def run_in_background(
         name: Optional short label to recognize the process later.
     """
     cwd = str(paths.resolve_virtual_path("/"))
+    # Honor dangerous mode so background commands match `execute`'s policy
+    # (real-filesystem access, no virtual-path rewriting). Read the env flag that
+    # apply_config_to_env round-trips at startup (and the subprocess inherits) —
+    # cheaper than reloading the full config from disk on every launch, and uses
+    # the same truthy parsing as every other bool env flag.
+    from ..llm.models import _env_flag_enabled
+
+    dangerous = _env_flag_enabled("EVOSCIENTIST_DANGEROUS_MODE")
     # Same path-rewriting + validation as execute (shared helper) so virtual paths
     # resolve to the workspace and the command can't bypass the sandbox checks.
-    command, error = prepare_sandbox_command(command, cwd)
+    command, error = prepare_sandbox_command(
+        command, cwd, virtual_mode=not dangerous, dangerous=dangerous
+    )
     if error:
         return error
     tid = _origin_thread_id(runtime)
@@ -85,9 +95,16 @@ def run_in_background(
         command, cwd, name, origin_thread_id=tid, on_exit=lambda p: _notify_done(p, tid)
     )
     label = f" (name={name!r})" if name else ""
+    # In dangerous mode `/` is the real root, so advertise the real log path;
+    # in virtual mode `/.bg_processes/...` correctly maps to the workspace.
+    log_path = (
+        f"{cwd}/.bg_processes/{process_id}.log"
+        if dangerous
+        else f"/.bg_processes/{process_id}.log"
+    )
     return (
         f"Started background process {process_id}{label}. "
-        f"Output -> /.bg_processes/{process_id}.log. "
+        f"Output -> {log_path}. "
         f"Poll with check_process('{process_id}'), stop with stop_process('{process_id}')."
     )
 
diff --git a/EvoScientist/prompts.py b/EvoScientist/prompts.py
index 4283f0f..f427f83 100644
--- a/EvoScientist/prompts.py
+++ b/EvoScientist/prompts.py
@@ -268,13 +268,11 @@ WRITING_GUIDELINES = """# Writing Guidelines
 # cfg.sandbox_execute_timeout (CustomSandboxBackend); this number is just the
 # documented default, and the per-command `timeout` override is the mechanism
 # that matters to the agent.
-SHELL_GUIDELINES = """# Shell Execution Guidelines
 
-When using the `execute` tool for shell commands:
-
-**Sandbox limits**: Commands default to a 300s timeout (a deployment may override this default) and 100 KB output. For a known long command (e.g. a download), pass `timeout` (up to 3600s): `execute(command="wget ...", timeout=600)`. For unbounded tasks, use background execution (below).
-
-**Short commands** (< 30 seconds): Run directly
+# Mode-independent core of the shell guidelines. ``{log_path}`` is the manual-
+# background redirect target: virtual ``/output.log`` (sandbox) or real
+# ``./output.log`` (dangerous mode, where ``/`` is the host root).
+_SHELL_GUIDELINES_CORE = """**Short commands** (< 30 seconds): Run directly
 ```bash
 python script.py
 pip install pandas
@@ -284,14 +282,48 @@ pip install pandas
 
 If you must background manually instead, you MUST redirect output to a file (otherwise the call blocks) and capture the PID:
 ```bash
-python long_task.py > /output.log 2>&1 &
-echo "PID: $!"          # check: ps -p <PID>   ·   stop: kill <PID>   ·   read: cat /output.log
+python long_task.py > {log_path} 2>&1 &
+echo "PID: $!"          # check: ps -p <PID>   ·   stop: kill <PID>   ·   read: cat {log_path}
 ```
 
 **Before heavy compute**: Estimate runtime. If likely > 5 minutes, use background execution from the start. If GPU memory is uncertain, start with a small test run (1 epoch, small batch) before the full run.
 
-This prevents blocking the conversation during long operations.
-"""
+This prevents blocking the conversation during long operations."""
+
+# Sandbox (default) header: virtual `/` workspace.
+_SHELL_GUIDELINES_SANDBOX_HEADER = """# Shell Execution Guidelines
+
+When using the `execute` tool for shell commands:
+
+**Sandbox limits**: Commands default to a 300s timeout (a deployment may override this default) and 100 KB output. For a known long command (e.g. a download), pass `timeout` (up to 3600s): `execute(command="wget ...", timeout=600)`. For unbounded tasks, use background execution (below)."""
+
+# Dangerous header: real filesystem, no virtual `/`. ``{cwd}`` = real working dir.
+_SHELL_GUIDELINES_DANGEROUS_HEADER = """# Shell Execution Guidelines (DANGEROUS MODE)
+
+You operate on the **host filesystem with real absolute paths** — there is no virtual workspace sandbox. Your current working directory is `{cwd}`. Use real absolute paths (e.g. `/Users/you/Documents/file.txt`) or paths relative to the cwd; `..` and `~` work normally. Run `pwd` any time you are unsure where you are.
+
+⚠ You can read, write, move, copy, and delete files **anywhere on this machine**. There is no workspace confinement and no approval prompt. Be deliberate: double-check destination paths before writing or deleting, and never operate on a path you have not confirmed.
+
+When using the `execute` tool for shell commands:
+
+**Limits**: Commands default to a 300s timeout (a deployment may override this default) and 100 KB output. For a known long command (e.g. a download), pass `timeout` (up to 3600s): `execute(command="wget ...", timeout=600)`. For unbounded tasks, use background execution (below)."""
+
+_SHELL_GUIDELINES_DANGEROUS_FOOTER = """
+
+**Still blocked even here**: privileged/system commands (`sudo`, `chmod`, `chown`, `mkfs`, `dd`, `shutdown`, `reboot`) and `rm -rf /` are rejected regardless of mode."""
+
+
+def _build_shell_guidelines(*, dangerous: bool = False, cwd: str | None = None) -> str:
+    """Assemble the shell guidelines from the shared core + per-mode header/footer."""
+    if dangerous:
+        header = _SHELL_GUIDELINES_DANGEROUS_HEADER.format(cwd=cwd or ".")
+        body = _SHELL_GUIDELINES_CORE.format(log_path="./output.log")
+        return f"{header}\n\n{body}{_SHELL_GUIDELINES_DANGEROUS_FOOTER}\n"
+    body = _SHELL_GUIDELINES_CORE.format(log_path="/output.log")
+    return f"{_SHELL_GUIDELINES_SANDBOX_HEADER}\n\n{body}\n"
+
+
+SHELL_GUIDELINES = _build_shell_guidelines()
 
 # =============================================================================
 # Sub-agent delegation strategy
@@ -392,6 +424,8 @@ def get_system_prompt(
     *,
     enable_observation_memory: bool = True,
     enable_observation_writes: bool = True,
+    dangerous: bool = False,
+    cwd: str | None = None,
 ) -> str:
     """Generate the complete static system prompt.
 
@@ -401,7 +435,7 @@ def get_system_prompt(
     2. :data:`EXPERIMENT_WORKFLOW`
     3. :data:`REPORT_TEMPLATE`
     4. :data:`WRITING_GUIDELINES`
-    5. :data:`SHELL_GUIDELINES`
+    5. :data:`SHELL_GUIDELINES` (or :data:`SHELL_GUIDELINES_DANGEROUS`)
     6. :data:`DELEGATION_STRATEGY`
     7. :data:`ASYNC_NOTIFICATIONS`
 
@@ -410,6 +444,12 @@ def get_system_prompt(
     similar per-turn values are not baked into this prompt. Memory-related
     workflow sections can vary with the configured memory controls.
 
+    Args:
+        dangerous: When True, use the real-filesystem shell guidance
+            (no virtual workspace) instead of the sandboxed default.
+        cwd: Real absolute working directory shown to the agent in
+            dangerous mode. Falls back to ``.`` when not provided.
+
     Returns:
         Combined static system prompt string.
     """
@@ -417,12 +457,17 @@ def get_system_prompt(
         enable_observation_memory=enable_observation_memory,
         enable_observation_writes=enable_observation_writes,
     )
+    shell_guidelines = (
+        _build_shell_guidelines(dangerous=True, cwd=cwd)
+        if dangerous
+        else SHELL_GUIDELINES
+    )
     sections = [
         EVOSCIENTIST_IDENTITY,
         workflow,
         REPORT_TEMPLATE,
         WRITING_GUIDELINES,
-        SHELL_GUIDELINES,
+        shell_guidelines,
         DELEGATION_STRATEGY,
         ASYNC_NOTIFICATIONS,
     ]
diff --git a/tests/test_backends.py b/tests/test_backends.py
index 01ac359..e49f9ed 100644
--- a/tests/test_backends.py
+++ b/tests/test_backends.py
@@ -12,6 +12,7 @@ from EvoScientist.backends import (
     CustomSandboxBackend,
     MergedSkillsBackend,
     convert_virtual_paths_in_command,
+    prepare_sandbox_command,
     validate_command,
 )
 
@@ -78,6 +79,34 @@ class TestValidateCommand:
         assert "/home/username/project" in result
 
 
+class TestValidateCommandDangerous:
+    """dangerous=True drops path confinement but keeps the command blocklist."""
+
+    def test_absolute_path_allowed(self):
+        assert validate_command("cat /etc/passwd", dangerous=True) is None
+
+    def test_traversal_allowed(self):
+        assert validate_command("cat ../../x", dangerous=True) is None
+
+    def test_home_tilde_allowed(self):
+        assert validate_command("cat ~/secrets.txt", dangerous=True) is None
+
+    def test_cd_absolute_allowed(self):
+        assert validate_command("cd /etc && ls", dangerous=True) is None
+
+    def test_sudo_still_blocked(self):
+        assert validate_command("sudo rm x", dangerous=True) is not None
+
+    def test_chmod_still_blocked(self):
+        assert validate_command("chmod 777 /tmp/x", dangerous=True) is not None
+
+    def test_dd_still_blocked(self):
+        assert validate_command("dd if=/dev/zero of=/x", dangerous=True) is not None
+
+    def test_rm_rf_root_still_blocked(self):
+        assert validate_command("rm -rf /", dangerous=True) is not None
+
+
 # === convert_virtual_paths_in_command ===
 
 
@@ -729,6 +758,55 @@ class TestResolvePath:
         assert backend._resolve_path(tmp_workspace) == backend._resolve_path("/")
 
 
+class TestResolvePathDangerous:
+    """Dangerous mode passes real absolute paths through unmangled."""
+
+    def test_absolute_path_unmangled(self, tmp_workspace):
+        backend = CustomSandboxBackend(root_dir=tmp_workspace, dangerous=True)
+        # OS-appropriate absolute path (drive-anchored on Windows) outside the ws.
+        target = Path(Path(tmp_workspace).anchor, "etc", "hosts")
+        resolved = Path(backend._resolve_path(str(target)))
+        # Dangerous mode must NOT confine/mangle it into the workspace.
+        assert Path(tmp_workspace) not in resolved.parents
+        assert resolved == target
+
+    def test_outside_workspace_not_confined(self, tmp_path):
+        ws = tmp_path / "ws"
+        ws.mkdir()
+        outside = tmp_path / "elsewhere" / "data.csv"
+        backend = CustomSandboxBackend(root_dir=str(ws), dangerous=True)
+        resolved = Path(backend._resolve_path(str(outside)))
+        assert resolved == outside  # real path, not pulled into the workspace
+
+    def test_dangerous_forces_virtual_mode_off(self, tmp_workspace):
+        backend = CustomSandboxBackend(
+            root_dir=tmp_workspace, virtual_mode=True, dangerous=True
+        )
+        assert backend.virtual_mode is False
+
+    def test_dangerous_skips_cwd_literal_rewrite(self, tmp_workspace):
+        """In dangerous mode the cwd->'./' rewrite must NOT mangle real args.
+
+        Regression: a non-path argument that merely contains the cwd string
+        (echo text, grep/git pattern) was being corrupted to './'.
+        """
+        cmd = f'echo "backup of {tmp_workspace}/data"'
+        prepared, error = prepare_sandbox_command(
+            cmd, tmp_workspace, virtual_mode=False, dangerous=True
+        )
+        assert error is None
+        assert prepared == cmd  # unchanged — no './' substitution
+
+    def test_non_dangerous_still_rewrites_cwd_literal(self, tmp_workspace):
+        """Default mode keeps the workspace-literal -> './' rewrite."""
+        cmd = f"cat {tmp_workspace}/file.txt"
+        prepared, error = prepare_sandbox_command(
+            cmd, tmp_workspace, virtual_mode=True, dangerous=False
+        )
+        assert error is None
+        assert prepared == "cat ./file.txt"
+
+
 # === CustomSandboxBackend.id ===
 
 
@@ -1352,6 +1430,17 @@ class TestExecuteTimeoutRecovery:
         assert cmd in resp.output
         assert "> /output.log 2>&1 &" in resp.output
 
+    def test_timeout_recovery_uses_relative_log_in_dangerous(self, tmp_workspace):
+        """Dangerous mode: recovery hint must not point the log at the host root."""
+        backend = CustomSandboxBackend(
+            root_dir=tmp_workspace, timeout=1, dangerous=True
+        )
+        resp = backend.execute(_sleep_cmd(10))
+        assert resp.exit_code == 124
+        assert "> ./output.log 2>&1 &" in resp.output
+        assert "cat ./output.log" in resp.output
+        assert "> /output.log" not in resp.output
+
     def test_timeout_recovery_captures_pid_and_offers_timeout(self, tmp_workspace):
         backend = CustomSandboxBackend(root_dir=tmp_workspace, timeout=1)
         resp = backend.execute(_sleep_cmd(10))
diff --git a/tests/test_background_middleware.py b/tests/test_background_middleware.py
index bb86217..38b55b6 100644
--- a/tests/test_background_middleware.py
+++ b/tests/test_background_middleware.py
@@ -109,6 +109,51 @@ def test_run_applies_virtual_path_rewriting(tmp_path, monkeypatch):
     assert captured["command"] == "python ./train.py"
 
 
+def _force_dangerous(monkeypatch, value=True):
+    """Make run_in_background see dangerous mode via the env flag it reads.
+
+    monkeypatch.setenv tracks the change and restores it on teardown, so this
+    cannot leak EVOSCIENTIST_DANGEROUS_MODE into other tests.
+    """
+    monkeypatch.setenv("EVOSCIENTIST_DANGEROUS_MODE", "true" if value else "false")
+
+
+def test_run_dangerous_allows_real_path_no_rewrite(tmp_path, monkeypatch):
+    """In dangerous mode, background commands keep real absolute paths (parity with execute)."""
+    monkeypatch.setattr("EvoScientist.paths.resolve_virtual_path", lambda _vp: tmp_path)
+    _force_dangerous(monkeypatch)
+    captured = {}
+
+    def _spy(command, cwd, name=None, *, origin_thread_id=None, on_exit=None):
+        captured["command"] = command
+        return "pidX"
+
+    monkeypatch.setattr(bg, "launch", _spy)
+    # Absolute path + traversal would be BLOCKED in normal mode; allowed here.
+    out = run_in_background.invoke({"command": "cat /etc/hosts && cat ../x"})
+    assert "blocked" not in out.lower()
+    assert captured["command"] == "cat /etc/hosts && cat ../x"  # no ./ rewrite
+    # Advertised log path is the real path, not the virtual /.bg_processes/.
+    assert f"{tmp_path}/.bg_processes/" in out
+    assert "Output -> /.bg_processes/" not in out
+
+
+def test_run_dangerous_still_blocks_privileged_command(tmp_path, monkeypatch):
+    """Dangerous mode must NOT relax the privileged-command blocklist."""
+    monkeypatch.setattr("EvoScientist.paths.resolve_virtual_path", lambda _vp: tmp_path)
+    _force_dangerous(monkeypatch)
+    launched = {"called": False}
+
+    def _spy(*args, **kwargs):
+        launched["called"] = True
+        return "should-not-happen"
+
+    monkeypatch.setattr(bg, "launch", _spy)
+    out = run_in_background.invoke({"command": "sudo rm x"})
+    assert launched["called"] is False
+    assert "blocked" in out.lower()
+
+
 def test_run_enqueues_completion_notification(tmp_path, monkeypatch):
     """A finished background process enqueues a shell completion notification."""
     from EvoScientist.cli import async_notifier
diff --git a/tests/test_cli_deploy.py b/tests/test_cli_deploy.py
index 7b18508..c0fbfb4 100644
--- a/tests/test_cli_deploy.py
+++ b/tests/test_cli_deploy.py
@@ -29,6 +29,7 @@ def _make_config(
     log_level: str = "warning",
     langgraph_dev_jobs_per_worker: int = 10,
     langgraph_dev_file_persistence: bool = True,
+    dangerous_mode: bool = False,
 ):
     return SimpleNamespace(
         default_workdir=default_workdir,
@@ -38,6 +39,7 @@ def _make_config(
         log_level=log_level,
         langgraph_dev_jobs_per_worker=langgraph_dev_jobs_per_worker,
         langgraph_dev_file_persistence=langgraph_dev_file_persistence,
+        dangerous_mode=dangerous_mode,
     )
 
 
diff --git a/tests/test_cli_serve.py b/tests/test_cli_serve.py
index 3cdd0aa..4eb7642 100644
--- a/tests/test_cli_serve.py
+++ b/tests/test_cli_serve.py
@@ -18,6 +18,7 @@ def _make_config(
     auto_approve: bool = False,
     auto_mode: bool = False,
     enable_ask_user: bool = True,
+    dangerous_mode: bool = False,
 ):
     return SimpleNamespace(
         channel_enabled="telegram",
@@ -28,6 +29,7 @@ def _make_config(
         auto_approve=auto_approve,
         auto_mode=auto_mode,
         enable_ask_user=enable_ask_user,
+        dangerous_mode=dangerous_mode,
         enable_async_subagents=False,
         memory_profile_enabled=True,
         memory_observations_enabled=True,
@@ -50,6 +52,7 @@ def _run_serve_once(
     auto_approve: bool = False,
     auto_mode: bool = False,
     ask_user: bool = False,
+    dangerous: bool = False,
 ):
     import EvoScientist.config as config_mod
 
@@ -108,6 +111,7 @@ def _run_serve_once(
         auto_approve=auto_approve,
         auto_mode=auto_mode,
         ask_user=ask_user,
+        dangerous=dangerous,
     )
     return order, captured
 
@@ -246,3 +250,17 @@ def test_serve_auto_mode_implies_auto_approve_and_disables_ask_user(
         "auto_approve": True,
         "enable_ask_user": False,
     }
+
+
+def test_serve_dangerous_sets_dangerous_mode(monkeypatch, tmp_path):
+    ws = str((tmp_path / "ws").resolve())
+    config = _make_config(default_workdir=ws)
+
+    _, captured = _run_serve_once(
+        monkeypatch,
+        config,
+        workdir=ws,
+        dangerous=True,
+    )
+
+    assert captured["cli_overrides"] == {"dangerous_mode": True}
diff --git a/tests/test_config.py b/tests/test_config.py
index d95b543..92f1427 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -28,6 +28,24 @@ from EvoScientist.config import (
 # =============================================================================
 
 
+@pytest.fixture(autouse=True)
+def _restore_dangerous_env():
+    """Snapshot/restore EVOSCIENTIST_DANGEROUS_MODE around every test.
+
+    apply_config_to_env writes this var via direct ``os.environ`` assignment, and
+    monkeypatch's ``delenv`` of an originally-absent key records no undo — so
+    without this, a test that turns dangerous mode on would leak the env var into
+    later tests (an order-dependent landmine, e.g. under pytest-randomly).
+    """
+    _sentinel = object()
+    _prev = os.environ.get("EVOSCIENTIST_DANGEROUS_MODE", _sentinel)
+    yield
+    if _prev is _sentinel:
+        os.environ.pop("EVOSCIENTIST_DANGEROUS_MODE", None)
+    else:
+        os.environ["EVOSCIENTIST_DANGEROUS_MODE"] = _prev
+
+
 @pytest.fixture
 def temp_config_dir(tmp_path, monkeypatch):
     """Use a temporary directory for config during tests."""
@@ -53,6 +71,7 @@ def temp_config_dir(tmp_path, monkeypatch):
         "EVOSCIENTIST_AUXILIARY_MODEL",
         "EVOSCIENTIST_AUXILIARY_PROVIDER",
         "EVOSCIENTIST_OPENROUTER_ANTHROPIC_PROMPT_CACHE",
+        "EVOSCIENTIST_DANGEROUS_MODE",
     ]:
         monkeypatch.delenv(key, raising=False)
     return config_dir
@@ -75,6 +94,7 @@ def clean_env(monkeypatch):
         "EVOSCIENTIST_AUXILIARY_MODEL",
         "EVOSCIENTIST_AUXILIARY_PROVIDER",
         "EVOSCIENTIST_OPENROUTER_ANTHROPIC_PROMPT_CACHE",
+        "EVOSCIENTIST_DANGEROUS_MODE",
     ]:
         monkeypatch.delenv(key, raising=False)
 
@@ -144,6 +164,18 @@ class TestEvoScientistConfig:
         assert config.model == "gpt-4o"
         assert config.default_mode == "run"
 
+    def test_dangerous_mode_default(self):
+        """dangerous_mode defaults off and does not force auto_approve."""
+        config = EvoScientistConfig()
+        assert config.dangerous_mode is False
+        assert config.auto_approve is False
+
+    def test_dangerous_mode_implies_auto_approve(self):
+        """Enabling dangerous_mode forces auto_approve via __post_init__."""
+        config = EvoScientistConfig(dangerous_mode=True)
+        assert config.dangerous_mode is True
+        assert config.auto_approve is True
+
 
 # =============================================================================
 # Test config path functions
@@ -612,6 +644,44 @@ class TestApplyConfigToEnv:
             "true"
         )
 
+    def test_dangerous_mode_round_trips_to_env(self, clean_env, monkeypatch):
+        """dangerous_mode set via CLI override must survive a fresh re-read.
+
+        Regression: a --dangerous CLI flag is never persisted to file/env, so a
+        fresh get_effective_config() (warning banner, run_in_background, the
+        langgraph dev subprocess) would read it back as False while the backend
+        is already unconfined. apply_config_to_env round-trips it to env.
+        """
+        from EvoScientist.config import get_effective_config
+
+        monkeypatch.delenv("EVOSCIENTIST_DANGEROUS_MODE", raising=False)
+        cfg = get_effective_config({"dangerous_mode": True})
+        assert cfg.dangerous_mode is True
+
+        apply_config_to_env(cfg)
+        assert os.environ.get("EVOSCIENTIST_DANGEROUS_MODE") == "true"
+        # The fresh, no-override read now agrees with the backend.
+        assert get_effective_config().dangerous_mode is True
+
+    def test_dangerous_mode_not_applied_when_off(self, clean_env, monkeypatch):
+        """dangerous_mode=False must not write the env var."""
+        monkeypatch.delenv("EVOSCIENTIST_DANGEROUS_MODE", raising=False)
+        apply_config_to_env(EvoScientistConfig())
+        assert os.environ.get("EVOSCIENTIST_DANGEROUS_MODE") is None
+
+    def test_dangerous_mode_off_clears_stale_env(self, clean_env, monkeypatch):
+        """Re-applying a non-dangerous config clears a previously-set env var.
+
+        Regression: the round-trip used to be set-only, so once dangerous mode
+        was applied in a process it could never be lowered — leaking unconfined
+        access into later non-dangerous reads.
+        """
+        monkeypatch.delenv("EVOSCIENTIST_DANGEROUS_MODE", raising=False)
+        apply_config_to_env(EvoScientistConfig(dangerous_mode=True))
+        assert os.environ.get("EVOSCIENTIST_DANGEROUS_MODE") == "true"
+        apply_config_to_env(EvoScientistConfig())  # dangerous off
+        assert os.environ.get("EVOSCIENTIST_DANGEROUS_MODE") is None
+
     def test_ollama_base_url_applied(self, clean_env, monkeypatch):
         """Test that ollama_base_url is applied to OLLAMA_BASE_URL env var."""
         monkeypatch.delenv("OLLAMA_BASE_URL", raising=False)
diff --git a/tests/test_prompts.py b/tests/test_prompts.py
index bfdff46..49f98b3 100644
--- a/tests/test_prompts.py
+++ b/tests/test_prompts.py
@@ -182,3 +182,24 @@ class TestShellGuidelines:
         """SHELL_GUIDELINES content should live ONLY in its own constant."""
         # Sentinel phrase unique to SHELL_GUIDELINES
         assert "Sandbox limits" not in EXPERIMENT_WORKFLOW
+
+
+class TestDangerousShellGuidelines:
+    def test_default_uses_virtual_paths(self):
+        result = get_system_prompt()
+        assert "> /output.log" in result
+        assert "DANGEROUS MODE" not in result
+
+    def test_dangerous_swaps_guidelines(self):
+        result = get_system_prompt(dangerous=True, cwd="/Users/me/ws/demo")
+        assert "DANGEROUS MODE" in result
+        assert "/Users/me/ws/demo" in result
+        # virtual-path example is gone
+        assert "> /output.log" not in result
+        # privileged-command blocklist still advertised
+        assert "sudo" in result
+        assert "rm -rf /" in result
+
+    def test_dangerous_without_cwd_falls_back(self):
+        result = get_system_prompt(dangerous=True)
+        assert "DANGEROUS MODE" in result