Codex Backend Architectural Immunity — Capability Consumption, Symmetric Env, and NotImplementedError Arch Tests

src/autoskillit/skills_extended/resolve-review/SKILL.md

@@ -468,6 +468,8 @@ classified `REJECT` with `category: "arch_violation"`.
 | Boot step symmetry | `test_boot_step_symmetry.py` | Both boot functions must call all required boot steps in the right order |
 | BackendCapabilities consumed | `test_capability_consumption.py` | Every `BackendCapabilities` field must have a production consumer — unused capability fields are prohibited |
 | BackendCapabilities documented | `test_capability_docstrings.py` | `BackendCapabilities` class and every field must have docstrings |
+| Env var symmetry | `test_env_symmetry.py` | `build_skill_session_cmd` and `build_food_truck_cmd` must both set required base env vars; `AGENT_BACKEND_ENV_VAR` must appear in food_truck |
+| No NotImplementedError in backends | `test_no_not_implemented.py` | Registered backend classes must not raise `NotImplementedError` — `CodingAgentBackend` is a Protocol, not an ABC |
 | Channel B timeout floor | `test_channel_b_timeout_guard.py` | Channel B calls with `timeout` below `TimeoutTier.CHANNEL_B` minimum |
 | Clone network timeouts | `test_clone_timeouts.py` | `subprocess.run()` with git network subcommands (clone/fetch/pull/push/ls-remote) in `clone.py` without `timeout=` |
 | Dispatch timeout resolver | `test_dispatch_timeout_guard.py` | `_run_dispatch` using hardcoded timeout instead of `resolve_dispatch_timeout()` |

tests/arch/CLAUDE.md

@@ -23,6 +23,7 @@ AST enforcement, sub-package layer contracts, and architectural invariant tests.
 | `test_backend_protocol_completeness.py` | Protocol completeness tests for CodingAgentBackend command builders |
 | `test_audit_feature_gates_skill.py` | Structural integrity tests for the audit-feature-gates skill |
 | `test_eval_agent_skill.py` | Structural integrity tests for the eval-agent skill |
+| `test_env_symmetry.py` | Architectural invariant: skill and food-truck builders must set the same required base env vars |
 | `test_boot_step_symmetry.py` | AST guard: both boot functions (_fleet_auto_gate_boot, _food_truck_auto_gate_boot) must call sweep_stale_dispatch_labels |
 | `test_bundled_recipes_split.py` | Enforcement: test_bundled_recipes.py split structure guard |
 | `test_cascade_map_guard.py` | REQ-GUARD-001..003, 005: CI guard validating cascade maps against AST-derived reverse import graph |
@@ -54,6 +55,7 @@ AST enforcement, sub-package layer contracts, and architectural invariant tests.
 | `test_no_error_dict_return.py` | AST guard: load_and_validate must not return dicts with 'error' key — errors flow via exceptions |
 | `test_flush_no_rid_guard.py` | AST guard: no requestId truthiness guard in flush_session_log turn extraction loop |
 | `test_no_inline_jsonl_request_id_dedup.py` | AST guard: no inline requestId dedup in session_log.py or tool_sequence_analysis.py |
+| `test_no_not_implemented.py` | Architectural invariant: no registered backend may raise NotImplementedError |
 | `test_resolve_turn_id_guard.py` | AST guard: no direct .get("requestId") calls outside _resolve_turn_id() in tool_sequence_analysis.py |
 | `test_protocol_names.py` | T5-T6: Protocol naming and DefaultSkillResolver export smoke tests |
 | `test_provider_profile_contract.py` | Tier 3 contract: _resolve_provider_profile must never return step_name as profile |

tests/arch/test_env_symmetry.py

@@ -0,0 +1,68 @@
+"""Architectural invariant: skill and food-truck builders must set the same required base env vars."""  # noqa: E501
+
+from pathlib import Path
+
+import pytest
+
+pytestmark = [pytest.mark.layer("arch"), pytest.mark.small]
+
+_REQUIRED_IN_BOTH: frozenset[str] = frozenset(
+    {
+        "AUTOSKILLIT_HEADLESS",
+        "AUTOSKILLIT_SESSION_TYPE",
+        "MAX_MCP_OUTPUT_TOKENS",
+    }
+)
+
+
+@pytest.fixture(autouse=True)
+def _clean_env(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("AUTOSKILLIT_CAMPAIGN_ID", raising=False)
+    monkeypatch.delenv("AUTOSKILLIT_KITCHEN_SESSION_ID", raising=False)
+    monkeypatch.delenv("AUTOSKILLIT_AGENT_BACKEND", raising=False)
+
+
+def test_skill_and_food_truck_share_required_env_vars() -> None:
+    """build_skill_session_cmd and build_food_truck_cmd must both set the required base env vars."""  # noqa: E501
+    from autoskillit.core.types._type_plugin_source import DirectInstall
+    from autoskillit.execution.backends import BACKEND_REGISTRY
+
+    assert BACKEND_REGISTRY, "BACKEND_REGISTRY is empty — test provides no coverage"
+    for name, cls in BACKEND_REGISTRY.items():
+        backend = cls()
+        skill_spec = backend.build_skill_session_cmd(
+            "/autoskillit:investigate", "/repo", completion_marker="DONE"
+        )
+        food_truck_spec = backend.build_food_truck_cmd(
+            orchestrator_prompt="test prompt",
+            plugin_source=DirectInstall(plugin_dir=Path("/plugins")),
+            cwd="/repo",
+            completion_marker="DONE",
+        )
+        for var in _REQUIRED_IN_BOTH:
+            assert var in skill_spec.env, f"{name}: {var} missing from build_skill_session_cmd env"
+            assert var in food_truck_spec.env, (
+                f"{name}: {var} missing from build_food_truck_cmd env"
+            )
+
+
+def test_agent_backend_env_var_in_food_truck(monkeypatch: pytest.MonkeyPatch) -> None:
+    """AUTOSKILLIT_AGENT_BACKEND must appear in build_food_truck_cmd env for every backend."""
+    from autoskillit.core.types._type_plugin_source import DirectInstall
+    from autoskillit.execution.backends import BACKEND_REGISTRY
+
+    # Ensure clean environment - remove any residual AGENT_BACKEND_ENV_VAR from host
+    monkeypatch.delenv("AUTOSKILLIT_AGENT_BACKEND", raising=False)
+
+    assert BACKEND_REGISTRY, "BACKEND_REGISTRY is empty — test provides no coverage"
+    for name, cls in BACKEND_REGISTRY.items():
+        backend = cls()
+        food_truck_spec = backend.build_food_truck_cmd(
+            orchestrator_prompt="test prompt",
+            plugin_source=DirectInstall(plugin_dir=Path("/plugins")),
+            cwd="/repo",
+            completion_marker="DONE",
+        )
+        assert "AUTOSKILLIT_AGENT_BACKEND" in food_truck_spec.env, (
+            f"{name}: AUTOSKILLIT_AGENT_BACKEND missing from build_food_truck_cmd env"
+        )

tests/arch/test_no_not_implemented.py

@@ -0,0 +1,37 @@
+"""Architectural invariant: no registered backend may raise NotImplementedError."""
+
+import ast
+import inspect
+
+import pytest
+
+pytestmark = [pytest.mark.layer("arch"), pytest.mark.small]
+
+
+def test_no_not_implemented_error_in_registered_backends() -> None:
+    """No method on any BACKEND_REGISTRY class should raise NotImplementedError.
+
+    CodingAgentBackend is a typing.Protocol, not an ABC — there are no legitimate
+    abstract stubs. Any raise NotImplementedError in a registered backend is a bug.
+    """
+    from autoskillit.execution.backends import BACKEND_REGISTRY
+
+    violations: list[str] = []
+    for name, cls in BACKEND_REGISTRY.items():
+        source = inspect.getsource(cls)
+        tree = ast.parse(source)
+        for node in ast.walk(tree):
+            if not isinstance(node, ast.Raise):
+                continue
+            exc = node.exc
+            if (
+                isinstance(exc, ast.Call)
+                and isinstance(exc.func, ast.Name)
+                and exc.func.id == "NotImplementedError"
+            ) or (isinstance(exc, ast.Name) and exc.id == "NotImplementedError"):
+                violations.append(f"{name}:{node.lineno}")
+
+    assert not violations, (
+        f"Registered backends must not raise NotImplementedError "
+        f"(CodingAgentBackend is a Protocol, not an ABC): {violations}"
+    )

tests/server/test_server_init_gate.py

@@ -66,6 +66,26 @@ async def test_redisable_subsets_hides_kitchen_core(self) -> None:
 
         mock_ctx.disable_components.assert_called_once_with(tags={"kitchen-core"})
 
+    @pytest.mark.anyio
+    async def test_tool_list_changes_after_enable_within_session(self) -> None:
+        """Tool list visible to a client changes when kitchen tags are enabled mid-session."""  # noqa: E501
+        from fastmcp.client import Client
+
+        from autoskillit.pipeline.gate import GATED_TOOLS
+        from autoskillit.server import mcp
+
+        async with Client(mcp) as client:
+            tools_before = {t.name for t in await client.list_tools()}
+            assert not (tools_before & GATED_TOOLS), "Kitchen tools should be hidden before enable"
+
+            mcp.enable(tags={"kitchen"})
+
+            tools_after = {t.name for t in await client.list_tools()}
+            new_tools = tools_after - tools_before
+            assert new_tools & GATED_TOOLS, (
+                "Enabling kitchen tags should make kitchen-gated tools visible"
+            )
+
 
 class TestGatedToolAccess:
     """Prompt-gated tool access: tools disabled by default, user-only activation."""