From 8eaab1297199cca331ff48793b410d7707030e0b Mon Sep 17 00:00:00 2001
From: CREDO23 <bakerathierry@gmail.com>
Date: Thu, 14 May 2026 17:40:12 +0200
Subject: [PATCH] multi_agent_chat/permissions: restructure slice + simplify
 factory

---
 .../middleware/shared/permissions/__init__.py | 19 ++--
 .../{interrupt => ask}/__init__.py            |  0
 .../shared/permissions/ask/decision.py        | 73 +++++++++++++++
 .../shared/permissions/ask/edit/__init__.py   | 10 ++
 .../shared/permissions/ask/edit/merge.py      | 22 +++++
 .../shared/permissions/ask/payload.py         | 79 ++++++++++++++++
 .../permissions/{interrupt => ask}/request.py | 21 +++--
 .../middleware/shared/permissions/decision.py | 91 -------------------
 .../permissions/interrupt/edit/__init__.py    |  6 --
 .../permissions/interrupt/edit/extract.py     | 34 -------
 .../permissions/interrupt/edit/merge.py       | 25 -----
 .../shared/permissions/interrupt/payload.py   | 43 ---------
 .../shared/permissions/middleware/core.py     | 16 ++--
 .../permissions/middleware/evaluation.py      |  2 +-
 .../shared/permissions/middleware/factory.py  | 68 ++++++++++++++
 .../{ => middleware}/pattern_resolver.py      |  0
 .../{ => middleware}/runtime_promote.py       |  0
 .../middleware/subagent/middleware_stack.py   | 21 ++++-
 18 files changed, 299 insertions(+), 231 deletions(-)
 rename surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/{interrupt => ask}/__init__.py (100%)
 create mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/decision.py
 create mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/edit/__init__.py
 create mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/edit/merge.py
 create mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/payload.py
 rename surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/{interrupt => ask}/request.py (54%)
 delete mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/decision.py
 delete mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/__init__.py
 delete mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/extract.py
 delete mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/merge.py
 delete mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/payload.py
 create mode 100644 surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/factory.py
 rename surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/{ => middleware}/pattern_resolver.py (100%)
 rename surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/{ => middleware}/runtime_promote.py (100%)

diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/__init__.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/__init__.py
index 95f62d3f1..c25c2b281 100644
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/__init__.py
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/__init__.py
@@ -1,16 +1,11 @@
-"""Pattern-based allow/deny/ask middleware with HITL fallback.
+"""Pattern-based allow/deny/ask middleware with HITL fallback (vertical slice).
 
-Public surface: :class:`PermissionMiddleware` plus
-:func:`normalize_permission_decision` for the streaming layer and the
-:data:`PatternResolver` type for callers that register per-tool resolvers.
+Public surface (one entry point only — every other symbol is an internal of
+the rule engine and stays inside ``middleware/``, ``ask/``, or ``deny.py``):
+
+- :func:`build_permission_mw` — construction recipe shared by every stack.
 """
 
-from .decision import normalize_permission_decision
-from .middleware import PermissionMiddleware
-from .pattern_resolver import PatternResolver
+from .middleware.factory import build_permission_mw
 
-__all__ = [
-    "PatternResolver",
-    "PermissionMiddleware",
-    "normalize_permission_decision",
-]
+__all__ = ["build_permission_mw"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/__init__.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/__init__.py
similarity index 100%
rename from surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/__init__.py
rename to surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/__init__.py
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/decision.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/decision.py
new file mode 100644
index 000000000..0fcad2ca0
--- /dev/null
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/decision.py
@@ -0,0 +1,73 @@
+"""Translate the unified langchain HITL envelope into permission-domain semantics.
+
+``PermissionMiddleware`` works with the canonical shape
+``{decision_type: "once" | "always" | "reject", feedback?: str, edited_args?: dict}``.
+The wire envelope arriving from langgraph already lives in the LC HITL shape
+(parsed once in :mod:`hitl_wire.decision`); this module performs the small
+domain mapping (``approve|edit`` → ``once``, ``always`` → ``always``,
+anything else → ``reject``) without re-implementing the envelope walk.
+
+Failing closed: any unrecognised decision becomes ``reject`` (with a warning)
+so the middleware never proceeds on ambiguous input.
+"""
+
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+from app.agents.multi_agent_chat.subagents.shared.hitl.wire import (
+    LC_DECISION_APPROVE,
+    LC_DECISION_EDIT,
+    LC_DECISION_REJECT,
+    SURFSENSE_DECISION_ALWAYS,
+    parse_lc_envelope,
+)
+
+logger = logging.getLogger(__name__)
+
+
+# ``approve`` and ``edit`` both mean "let this call go through this once". The
+# legacy SurfSense bare-scalar values (``once`` / ``always`` / ``reject``)
+# pass through unchanged so historical resume payloads still work.
+_LC_TO_PERMISSION: dict[str, str] = {
+    LC_DECISION_APPROVE: "once",
+    LC_DECISION_EDIT: "once",
+    SURFSENSE_DECISION_ALWAYS: "always",
+    LC_DECISION_REJECT: "reject",
+    "once": "once",
+    "always": "always",
+    "reject": "reject",
+}
+
+
+def normalize_permission_decision(envelope: Any) -> dict[str, Any]:
+    """Project the user's reply into the canonical permission decision shape.
+
+    Args:
+        envelope: The raw resume value from langgraph (LC HITL envelope, a
+            bare scalar string, or a pre-canonical dict).
+
+    Returns:
+        ``{"decision_type": "once"|"always"|"reject"}`` plus optional
+        ``feedback`` (``reject`` with a user message) and ``edited_args``
+        (``edit`` reply with non-empty arg overrides).
+    """
+    parsed = parse_lc_envelope(envelope)
+    mapped = _LC_TO_PERMISSION.get(parsed.decision_type)
+    if mapped is None:
+        logger.warning(
+            "Unknown permission decision %r; treating as reject",
+            parsed.decision_type,
+        )
+        mapped = "reject"
+
+    out: dict[str, Any] = {"decision_type": mapped}
+    if parsed.message:
+        out["feedback"] = parsed.message
+    if parsed.edited_args:
+        out["edited_args"] = parsed.edited_args
+    return out
+
+
+__all__ = ["normalize_permission_decision"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/edit/__init__.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/edit/__init__.py
new file mode 100644
index 000000000..2921cbe70
--- /dev/null
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/edit/__init__.py
@@ -0,0 +1,10 @@
+"""Apply ``edit`` permission decisions to tool calls.
+
+Edited-arg extraction now lives in :mod:`hitl_wire.decision` (single parser
+for all approval paths); this module owns the merge step that produces a
+fresh tool-call dict for the orchestrator.
+"""
+
+from .merge import merge_edited_args
+
+__all__ = ["merge_edited_args"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/edit/merge.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/edit/merge.py
new file mode 100644
index 000000000..21474ad52
--- /dev/null
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/edit/merge.py
@@ -0,0 +1,22 @@
+"""Apply edited args to a tool call (shallow merge, no mutation).
+
+Edited values override originals; keys absent from ``edited_args`` keep
+their original values, so partial edits are safe. Returns a NEW tool-call
+dict so the caller can swap it into ``AIMessage.tool_calls`` without
+aliasing the live message object.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+
+def merge_edited_args(
+    tool_call: dict[str, Any], edited_args: dict[str, Any]
+) -> dict[str, Any]:
+    original_args = tool_call.get("args") or {}
+    merged_args = {**original_args, **edited_args}
+    return {**tool_call, "args": merged_args}
+
+
+__all__ = ["merge_edited_args"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/payload.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/payload.py
new file mode 100644
index 000000000..270a3888d
--- /dev/null
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/payload.py
@@ -0,0 +1,79 @@
+"""Build the permission-ask interrupt payload (LC HITL wire + SurfSense context).
+
+The FE's PermissionCard renders from:
+
+- Standard langchain fields (``action_requests``, ``review_configs``) — drive
+  the action chrome and the parallel-HITL routing layer (``task_tool``,
+  ``resume_routing``) that batches concurrent approvals.
+- ``interrupt_type="permission_ask"`` — selects the permission card variant.
+- ``context.patterns`` / ``context.rules`` — explain *why* the ask fired.
+- ``context.always`` — the patterns the user can promote to a permanent
+  allow rule with a single ``"always"`` reply.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+from app.agents.multi_agent_chat.subagents.shared.hitl.wire import (
+    LC_DECISION_APPROVE,
+    LC_DECISION_EDIT,
+    LC_DECISION_REJECT,
+    SURFSENSE_DECISION_ALWAYS,
+    build_lc_hitl_payload,
+)
+from app.agents.new_chat.permissions import Rule
+
+PERMISSION_ASK_INTERRUPT_TYPE = "permission_ask"
+
+# The full palette a permission card may surface: approve once, edit-then-
+# approve, reject, or "always" to promote the matched pattern.
+_PERMISSION_ASK_DECISIONS: list[str] = [
+    LC_DECISION_APPROVE,
+    LC_DECISION_REJECT,
+    LC_DECISION_EDIT,
+    SURFSENSE_DECISION_ALWAYS,
+]
+
+
+def build_permission_ask_payload(
+    *,
+    tool_name: str,
+    args: dict[str, Any],
+    patterns: list[str],
+    rules: list[Rule],
+) -> dict[str, Any]:
+    """Build the permission-ask interrupt payload.
+
+    Args:
+        tool_name: The tool whose call is being reviewed.
+        args: The tool call arguments shown in the card.
+        patterns: Wildcard patterns the call matched (drives ``always``).
+        rules: Matched ruleset entries surfaced for explainability.
+
+    Returns:
+        A dict suitable for ``langgraph.types.interrupt(...)`` carrying both
+        the LC HITL standard fields and SurfSense-specific context.
+    """
+    context: dict[str, Any] = {
+        "patterns": patterns,
+        "rules": [
+            {
+                "permission": r.permission,
+                "pattern": r.pattern,
+                "action": r.action,
+            }
+            for r in rules
+        ],
+        "always": patterns,
+    }
+    return build_lc_hitl_payload(
+        tool_name=tool_name,
+        args=args,
+        allowed_decisions=_PERMISSION_ASK_DECISIONS,
+        interrupt_type=PERMISSION_ASK_INTERRUPT_TYPE,
+        context=context,
+    )
+
+
+__all__ = ["PERMISSION_ASK_INTERRUPT_TYPE", "build_permission_ask_payload"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/request.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/request.py
similarity index 54%
rename from surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/request.py
rename to surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/request.py
index abd2871b8..42e47ef98 100644
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/request.py
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/ask/request.py
@@ -1,12 +1,12 @@
-"""Request a permission decision from the user (side-effectful entry point).
+"""Side-effectful entry point: pause the graph and return the permission decision.
 
-Wraps :func:`langgraph.types.interrupt` with the OTel spans that the
-SurfSense dashboard expects, then normalises the resume value through
-:func:`decision.normalize_permission_decision`.
+Wraps :func:`langgraph.types.interrupt` with the OTel spans the SurfSense
+dashboard expects, then projects the resume value through
+:func:`normalize_permission_decision` so the middleware downstream only
+sees the canonical permission-domain shape.
 
-When ``emit_interrupt`` is ``False`` the call short-circuits to
-``reject``; this is used by non-interactive deployments where ``ask`` must
-not block.
+When ``emit_interrupt`` is ``False`` the call short-circuits to ``reject``;
+this is used by non-interactive deployments where ``ask`` must not block.
 """
 
 from __future__ import annotations
@@ -18,8 +18,8 @@ from langgraph.types import interrupt
 from app.agents.new_chat.permissions import Rule
 from app.observability import otel as ot
 
-from ..decision import normalize_permission_decision
-from .payload import build_permission_ask_payload
+from .decision import normalize_permission_decision
+from .payload import PERMISSION_ASK_INTERRUPT_TYPE, build_permission_ask_payload
 
 
 def request_permission_decision(
@@ -30,6 +30,7 @@ def request_permission_decision(
     rules: list[Rule],
     emit_interrupt: bool,
 ) -> dict[str, Any]:
+    """Pause for an ``ask`` decision; return the canonical permission decision dict."""
     if not emit_interrupt:
         return {"decision_type": "reject"}
 
@@ -43,7 +44,7 @@ def request_permission_decision(
             pattern=patterns[0] if patterns else None,
             extra={"permission.patterns": list(patterns)},
         ),
-        ot.interrupt_span(interrupt_type="permission_ask"),
+        ot.interrupt_span(interrupt_type=PERMISSION_ASK_INTERRUPT_TYPE),
     ):
         decision = interrupt(payload)
     return normalize_permission_decision(decision)
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/decision.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/decision.py
deleted file mode 100644
index bb8f9ea25..000000000
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/decision.py
+++ /dev/null
@@ -1,91 +0,0 @@
-"""Coerce inbound permission decisions to a canonical dict shape.
-
-Two wire formats are accepted:
-- SurfSense legacy: ``{"decision_type": "once"|"always"|"reject", "feedback"?}``.
-- LangChain HITL envelope: ``{"decisions": [{"type": "approve"|"edit"|"reject", ...}]}``.
-
-The middleware downstream only inspects the canonical shape returned here,
-so adding a new envelope means changing this module alone.
-
-The middleware fails closed: any unrecognised payload becomes ``reject``
-(with a warning) so the agent never proceeds on ambiguous input.
-
-When the reply is an ``edit``, the result keeps ``decision_type="once"``
-(the call still goes through) and adds an ``edited_args`` key holding the
-user-modified ``args`` dict. The orchestrator merges those into the
-``tool_call`` before keeping it; see :mod:`interrupt.edit.merge`.
-"""
-
-from __future__ import annotations
-
-import logging
-from typing import Any
-
-from .interrupt.edit import extract_edited_args
-
-logger = logging.getLogger(__name__)
-
-
-# ``edit`` collapses to ``once``; any ``edited_args`` ride on the result.
-_LC_TYPE_TO_PERMISSION_DECISION: dict[str, str] = {
-    "approve": "once",
-    "reject": "reject",
-    "edit": "once",
-}
-
-
-def normalize_permission_decision(decision: Any) -> dict[str, Any]:
-    """Return ``{"decision_type": ..., "feedback"?: str, "edited_args"?: dict}``."""
-    if isinstance(decision, str):
-        return {"decision_type": decision}
-    if not isinstance(decision, dict):
-        logger.warning(
-            "Unrecognized permission resume value (%s); treating as reject",
-            type(decision).__name__,
-        )
-        return {"decision_type": "reject"}
-
-    if decision.get("decision_type"):
-        return decision
-
-    payload: dict[str, Any] = decision
-    decisions = decision.get("decisions")
-    if isinstance(decisions, list) and decisions:
-        first = decisions[0]
-        if isinstance(first, dict):
-            payload = first
-
-    raw_type = payload.get("type") or payload.get("decision_type")
-    if not raw_type:
-        logger.warning(
-            "Permission resume missing decision type (keys=%s); treating as reject",
-            list(payload.keys()),
-        )
-        return {"decision_type": "reject"}
-
-    raw_type = str(raw_type).lower()
-    mapped = _LC_TYPE_TO_PERMISSION_DECISION.get(raw_type)
-    if mapped is None:
-        # Tolerate legacy values arriving without ``decision_type`` wrapping.
-        if raw_type in {"once", "always", "reject"}:
-            mapped = raw_type
-        else:
-            logger.warning(
-                "Unknown permission decision type %r; treating as reject", raw_type
-            )
-            mapped = "reject"
-
-    out: dict[str, Any] = {"decision_type": mapped}
-    feedback = payload.get("feedback") or payload.get("message")
-    if isinstance(feedback, str) and feedback.strip():
-        out["feedback"] = feedback
-
-    if raw_type == "edit":
-        edited = extract_edited_args(payload)
-        if edited:
-            out["edited_args"] = edited
-
-    return out
-
-
-__all__ = ["normalize_permission_decision"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/__init__.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/__init__.py
deleted file mode 100644
index 993bc50b9..000000000
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/__init__.py
+++ /dev/null
@@ -1,6 +0,0 @@
-"""Apply ``edit`` permission decisions to tool calls (extract + merge)."""
-
-from .extract import extract_edited_args
-from .merge import merge_edited_args
-
-__all__ = ["extract_edited_args", "merge_edited_args"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/extract.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/extract.py
deleted file mode 100644
index 85d365ece..000000000
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/extract.py
+++ /dev/null
@@ -1,34 +0,0 @@
-"""Extract edited args from a permission decision payload.
-
-Two shapes are accepted (mirrors :func:`app.agents.new_chat.tools.hitl._parse_decision`):
-
-- LangChain HITL envelope: ``{"edited_action": {"args": {...}}}``.
-- Legacy flat shape: ``{"args": {...}}``.
-
-Returns ``None`` when no edited args are present. The orchestrator decides
-whether to merge them (see :mod:`interrupt.edit.merge`); this module is pure parsing.
-"""
-
-from __future__ import annotations
-
-from typing import Any
-
-
-def extract_edited_args(decision_payload: dict[str, Any] | None) -> dict[str, Any] | None:
-    if not isinstance(decision_payload, dict):
-        return None
-
-    edited_action = decision_payload.get("edited_action")
-    if isinstance(edited_action, dict):
-        edited_args = edited_action.get("args")
-        if isinstance(edited_args, dict):
-            return edited_args
-
-    flat_args = decision_payload.get("args")
-    if isinstance(flat_args, dict):
-        return flat_args
-
-    return None
-
-
-__all__ = ["extract_edited_args"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/merge.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/merge.py
deleted file mode 100644
index 6632c677c..000000000
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/edit/merge.py
+++ /dev/null
@@ -1,25 +0,0 @@
-"""Apply edited args to a tool call.
-
-Semantics match :func:`app.agents.new_chat.tools.hitl.request_approval`'s
-``final_params = {**params, **edited_params}`` — shallow merge, edited
-values override originals. Keys absent from ``edited_args`` keep their
-original values, so partial edits are safe.
-
-Returns a NEW ``tool_call`` dict (the input is not mutated) so the caller
-can swap it into the ``AIMessage.tool_calls`` list without aliasing.
-"""
-
-from __future__ import annotations
-
-from typing import Any
-
-
-def merge_edited_args(
-    tool_call: dict[str, Any], edited_args: dict[str, Any]
-) -> dict[str, Any]:
-    original_args = tool_call.get("args") or {}
-    merged_args = {**original_args, **edited_args}
-    return {**tool_call, "args": merged_args}
-
-
-__all__ = ["merge_edited_args"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/payload.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/payload.py
deleted file mode 100644
index d5de1c209..000000000
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/interrupt/payload.py
+++ /dev/null
@@ -1,43 +0,0 @@
-"""Build the ``permission_ask`` interrupt payload (pure data).
-
-The frontend's streaming layer keys off ``type`` and renders the approval
-card from ``action`` (the tool call being reviewed) and ``context``
-(the matched rules and patterns that prompted the ask). ``context.always``
-lists the patterns the user can promote to a permanent allow rule with a
-single ``"always"`` reply.
-"""
-
-from __future__ import annotations
-
-from typing import Any
-
-from app.agents.new_chat.permissions import Rule
-
-
-def build_permission_ask_payload(
-    *,
-    tool_name: str,
-    args: dict[str, Any],
-    patterns: list[str],
-    rules: list[Rule],
-) -> dict[str, Any]:
-    return {
-        "type": "permission_ask",
-        # ``params`` (not ``args``) is what SurfSense's streaming normalizer forwards.
-        "action": {"tool": tool_name, "params": args or {}},
-        "context": {
-            "patterns": patterns,
-            "rules": [
-                {
-                    "permission": r.permission,
-                    "pattern": r.pattern,
-                    "action": r.action,
-                }
-                for r in rules
-            ],
-            "always": patterns,
-        },
-    }
-
-
-__all__ = ["build_permission_ask_payload"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/core.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/core.py
index d2370889c..a8bb24143 100644
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/core.py
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/core.py
@@ -5,10 +5,10 @@ LangChain's :class:`HumanInTheLoopMiddleware` only supports a static
 allow/deny/ask, no glob patterns, no per-space/per-thread overrides, and
 no auto-deny synthesis.
 
-This middleware layers OpenCode's wildcard-ruleset model on top of
-SurfSense's ``interrupt({type, action, context})`` payload shape (see
-:mod:`app.agents.new_chat.tools.hitl`) so the frontend keeps working
-unchanged.
+This middleware layers OpenCode's wildcard-ruleset model on top of the
+unified langchain HITL wire format (see :mod:`hitl_wire`), so it sits
+beside ``HumanInTheLoopMiddleware`` and self-gated approvals on a single
+parallel-HITL routing layer in ``task_tool`` + ``resume_routing``.
 
 Per-tool-call flow inside :meth:`_process`:
 
@@ -47,13 +47,13 @@ from langgraph.runtime import Runtime
 from app.agents.new_chat.errors import CorrectedError, RejectedError
 from app.agents.new_chat.permissions import Ruleset
 
+from ..ask.edit import merge_edited_args
+from ..ask.request import request_permission_decision
 from ..deny import build_deny_message
-from ..interrupt.edit import merge_edited_args
-from ..interrupt.request import request_permission_decision
-from ..pattern_resolver import PatternResolver
-from ..runtime_promote import persist_always
 from .evaluation import evaluate_tool_call
+from .pattern_resolver import PatternResolver
 from .ruleset_view import all_rulesets
+from .runtime_promote import persist_always
 
 logger = logging.getLogger(__name__)
 
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/evaluation.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/evaluation.py
index 6777aa093..51531c4eb 100644
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/evaluation.py
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/evaluation.py
@@ -24,7 +24,7 @@ from app.agents.new_chat.permissions import (
     evaluate_many,
 )
 
-from ..pattern_resolver import PatternResolver, default_pattern_resolver
+from .pattern_resolver import PatternResolver, default_pattern_resolver
 
 logger = logging.getLogger(__name__)
 
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/factory.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/factory.py
new file mode 100644
index 000000000..4b760ec6f
--- /dev/null
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/factory.py
@@ -0,0 +1,68 @@
+"""Construction recipe for :class:`PermissionMiddleware` shared across stacks.
+
+Single source of truth used by both the main-agent stack and every subagent
+stack. Rule layers are evaluated earliest-to-latest (last match wins,
+matching OpenCode's ``permission/index.ts`` evaluation order):
+
+1. ``surfsense_defaults`` — single ``allow */*`` rule. Connector tools
+   already self-gate via :func:`request_approval`, so the rule engine only
+   needs to *deny* what the user has explicitly forbidden; the default
+   ``ask`` fallback would otherwise double-prompt every safe read-only
+   call.
+2. ``extra_rulesets`` — caller-supplied policies. The KB subagent contributes
+   its destructive-FS ``ask`` rules here; connectors will follow once
+   they migrate off ``interrupt_on``.
+
+Connector deny synthesis from ``new_chat._synthesize_connector_deny_rules``
+is intentionally NOT replicated: the multi-agent orchestrator already
+excludes entire subagents whose required connectors are missing
+(``SUBAGENT_TO_REQUIRED_CONNECTOR_MAP``), so the per-tool deny pass is
+redundant here.
+"""
+
+from __future__ import annotations
+
+from app.agents.new_chat.feature_flags import AgentFeatureFlags
+from app.agents.new_chat.permissions import Rule, Ruleset
+
+from .core import PermissionMiddleware
+
+_SURFSENSE_DEFAULTS = Ruleset(
+    rules=[Rule(permission="*", pattern="*", action="allow")],
+    origin="surfsense_defaults",
+)
+
+
+def build_permission_mw(
+    *,
+    flags: AgentFeatureFlags,
+    extra_rulesets: list[Ruleset] | None = None,
+) -> PermissionMiddleware | None:
+    """Return a configured :class:`PermissionMiddleware` or ``None`` when no work is needed.
+
+    Args:
+        flags: Feature toggles. ``enable_permission`` switches the engine on;
+            ``disable_new_agent_stack`` overrides everything for safety.
+        extra_rulesets: Caller-supplied rulesets layered after the defaults.
+            Subagents pass their own policy here so each subagent owns its
+            rules without aliasing a shared engine. Presence of any extra
+            ruleset forces the middleware on regardless of
+            ``enable_permission`` — an explicit ``ask`` rule always asks.
+
+    Returns:
+        ``None`` when the engine has no rules to enforce
+        (``enable_permission=False`` and no extras); a configured middleware
+        otherwise.
+    """
+    permission_enabled = flags.enable_permission and not flags.disable_new_agent_stack
+    has_extras = bool(extra_rulesets)
+    if not (permission_enabled or has_extras):
+        return None
+
+    rulesets: list[Ruleset] = [_SURFSENSE_DEFAULTS]
+    if extra_rulesets:
+        rulesets.extend(extra_rulesets)
+    return PermissionMiddleware(rulesets=rulesets)
+
+
+__all__ = ["build_permission_mw"]
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/pattern_resolver.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/pattern_resolver.py
similarity index 100%
rename from surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/pattern_resolver.py
rename to surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/pattern_resolver.py
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/runtime_promote.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/runtime_promote.py
similarity index 100%
rename from surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/runtime_promote.py
rename to surfsense_backend/app/agents/multi_agent_chat/middleware/shared/permissions/middleware/runtime_promote.py
diff --git a/surfsense_backend/app/agents/multi_agent_chat/middleware/subagent/middleware_stack.py b/surfsense_backend/app/agents/multi_agent_chat/middleware/subagent/middleware_stack.py
index 9889e629a..aa6211fcc 100644
--- a/surfsense_backend/app/agents/multi_agent_chat/middleware/subagent/middleware_stack.py
+++ b/surfsense_backend/app/agents/multi_agent_chat/middleware/subagent/middleware_stack.py
@@ -3,7 +3,8 @@
 Mirrors ``middleware/stack.py`` (the orchestrator's middleware stack) but
 exposes its contents as a dict keyed by purpose so specialists can pick
 the entries they need and decide ordering. The default consumer
-(``pack_subagent``) prepends every non-``None`` value in insertion order.
+(:func:`pack_subagent`) prepends every non-``None`` value in insertion
+order, so ``None`` slots are silently skipped.
 
 Registry subagents never touch the SurfSense filesystem — that capability
 belongs to ``knowledge_base`` — so no FS middleware is exposed here.
@@ -13,6 +14,9 @@ from __future__ import annotations
 
 from typing import Any
 
+from app.agents.new_chat.feature_flags import AgentFeatureFlags
+
+from ..shared.permissions import build_permission_mw
 from ..shared.resilience import ResilienceMiddlewares
 from ..shared.todos import build_todos_mw
 
@@ -20,9 +24,24 @@ from ..shared.todos import build_todos_mw
 def build_subagent_middleware_stack(
     *,
     resilience: ResilienceMiddlewares,
+    flags: AgentFeatureFlags | None = None,
 ) -> dict[str, Any]:
+    """Assemble the dict of middlewares prepended to every subagent's stack.
+
+    Args:
+        resilience: Pre-built retry / fallback / call-limit middlewares
+            (shared with the orchestrator stack to keep behaviour symmetric).
+        flags: Feature flags driving optional layers. ``None`` disables the
+            permission layer (used in tests that only need todos+resilience).
+
+    Returns:
+        Insertion-ordered dict; ``None`` values are tolerated and dropped by
+        the consumer so callers can flip slots on/off without reshaping.
+    """
+    permission = build_permission_mw(flags=flags) if flags is not None else None
     return {
         "todos": build_todos_mw(),
+        "permission": permission,
         "retry": resilience.retry,
         "fallback": resilience.fallback,
         "model_call_limit": resilience.model_call_limit,