diff --git a/PythonModels/systems/test_mql.py b/PythonModels/systems/test_mql.py
index 86ab151..b1a1572 100644
--- a/PythonModels/systems/test_mql.py
+++ b/PythonModels/systems/test_mql.py
@@ -3915,6 +3915,49 @@ class TestMqlSystem:
             source=source,
         )
 
+    def discover_pneumatic_branch_topology(self):
+        from PythonModels.systems.test_mql_closure import (
+            TestMqlPneumaticTopologyCandidate,
+            TestMqlPneumaticTopologyDiscovery,
+        )
+
+        typed_aliases = set(self._pneumatic_components_by_alias())
+        blocked_candidates = []
+        for spec in CONNECTION_SPECS:
+            source_component = str(spec["source_component"])
+            target_component = str(spec["target_component"])
+            source_is_typed = source_component in typed_aliases
+            target_is_typed = target_component in typed_aliases
+            if not (source_is_typed or target_is_typed):
+                continue
+
+            line_submodel = str(spec["submodel"])
+            if source_is_typed and target_is_typed:
+                reason = "direct typed pneumatic connection is not a complete volume-orifice-volume branch"
+            elif line_submodel == "DIRECT":
+                reason = "requires AMESim boundary component interpretation before closure construction"
+            else:
+                reason = "requires AMESim node/line submodel interpretation before closure construction"
+
+            blocked_candidates.append(
+                TestMqlPneumaticTopologyCandidate(
+                    connection_alias=str(spec["alias"]),
+                    line_submodel=line_submodel,
+                    source_component=source_component,
+                    source_port=str(spec["source_port"]),
+                    target_component=target_component,
+                    target_port=str(spec["target_port"]),
+                    source_is_typed_pneumatic=source_is_typed,
+                    target_is_typed_pneumatic=target_is_typed,
+                    reason=reason,
+                )
+            )
+
+        return TestMqlPneumaticTopologyDiscovery(
+            branch_specs=(),
+            blocked_candidates=tuple(blocked_candidates),
+        )
+
     def pneumatic_branch_closure_from_spec(self, spec):
         return self.pneumatic_branch_closure(
             name=spec.name,
diff --git a/PythonModels/systems/test_mql_closure.py b/PythonModels/systems/test_mql_closure.py
index 7c84ac2..d7c0488 100644
--- a/PythonModels/systems/test_mql_closure.py
+++ b/PythonModels/systems/test_mql_closure.py
@@ -20,6 +20,25 @@ class TestMqlPneumaticBranchSpec:
     source: str = "manual"
 
 
+@dataclass(frozen=True)
+class TestMqlPneumaticTopologyCandidate:
+    connection_alias: str
+    line_submodel: str
+    source_component: str
+    source_port: str
+    target_component: str
+    target_port: str
+    source_is_typed_pneumatic: bool
+    target_is_typed_pneumatic: bool
+    reason: str
+
+
+@dataclass(frozen=True)
+class TestMqlPneumaticTopologyDiscovery:
+    branch_specs: tuple[TestMqlPneumaticBranchSpec, ...]
+    blocked_candidates: tuple[TestMqlPneumaticTopologyCandidate, ...]
+
+
 @dataclass(frozen=True)
 class TestMqlPneumaticBranchComponents:
     name: str
diff --git a/tests/test_test_mql_branch_simulation.py b/tests/test_test_mql_branch_simulation.py
index 2002d74..9869c22 100644
--- a/tests/test_test_mql_branch_simulation.py
+++ b/tests/test_test_mql_branch_simulation.py
@@ -86,6 +86,33 @@ class TestMqlPneumaticBranchSimulationTests(unittest.TestCase):
         self.assertGreater(series["pn_general_chamber.p"][0], series["pn_general_chamber.p"][-1])
         self.assertLess(series["pn_c1_8.p"][0], series["pn_c1_8.p"][-1])
 
+    def test_discover_pneumatic_branch_topology_reports_blocked_candidates(self) -> None:
+        system = TestMqlSystem()
+
+        discovery = system.discover_pneumatic_branch_topology()
+
+        self.assertEqual(discovery.branch_specs, ())
+        self.assertEqual(len(discovery.blocked_candidates), 48)
+        candidates = {
+            candidate.connection_alias: candidate
+            for candidate in discovery.blocked_candidates
+        }
+        chamber_candidate = candidates["pneumatic_69"]
+        self.assertEqual(chamber_candidate.line_submodel, "PNL0001")
+        self.assertEqual(chamber_candidate.source_component, "pnnode4_16")
+        self.assertEqual(chamber_candidate.target_component, "pn_c1_8")
+        self.assertFalse(chamber_candidate.source_is_typed_pneumatic)
+        self.assertTrue(chamber_candidate.target_is_typed_pneumatic)
+        self.assertIn("node/line", chamber_candidate.reason)
+
+        orifice_candidate = candidates["pneumatic_96"]
+        self.assertEqual(orifice_candidate.line_submodel, "PNL0001")
+        self.assertEqual(orifice_candidate.source_component, "pn_node3_8")
+        self.assertEqual(orifice_candidate.target_component, "pn_orifice_18")
+        self.assertFalse(orifice_candidate.source_is_typed_pneumatic)
+        self.assertTrue(orifice_candidate.target_is_typed_pneumatic)
+        self.assertIn("node/line", orifice_candidate.reason)
+
     def test_simulate_pneumatic_branch_rejects_invalid_component_aliases(self) -> None:
         system = TestMqlSystem()