feat: exempt BoundaryAction blocks from G-002 signature completeness check

packages/gds-framework/gds/compiler/compile.py

@@ -208,6 +208,7 @@ def _default_block_compiler(block: AtomicBlock) -> BlockIR:
     """Default block compiler — extracts name and interface slots."""
     return BlockIR(
         name=block.name,
+        block_type=getattr(block, "kind", ""),
         signature=(
             _ports_to_sig(block.interface.forward_in),
             _ports_to_sig(block.interface.forward_out),

packages/gds-framework/gds/verification/generic_checks.py

@@ -65,13 +65,23 @@ def check_g001_domain_codomain_matching(system: SystemIR) -> list[Finding]:
 def check_g002_signature_completeness(system: SystemIR) -> list[Finding]:
     """G-002: Every block must have at least one non-empty input slot
     and at least one non-empty output slot.
+
+    BoundaryAction blocks (block_type == "boundary") are exempt from the
+    input requirement — they have no inputs by design, since they model
+    exogenous signals entering the system from outside.
     """
     findings = []
     for block in system.blocks:
         fwd_in, fwd_out, bwd_in, bwd_out = block.signature
         has_input = bool(fwd_in) or bool(bwd_in)
         has_output = bool(fwd_out) or bool(bwd_out)
-        has_required = has_input and has_output
+
+        # BoundaryAction blocks have no inputs by design — only check outputs
+        is_boundary = block.block_type == "boundary"
+        if is_boundary:
+            has_required = has_output
+        else:
+            has_required = has_input and has_output
 
         missing = []
         if not has_input:

packages/gds-framework/tests/test_verification.py

@@ -82,6 +82,57 @@ def test_missing_output_flags(self):
         failed = [f for f in findings if not f.passed]
         assert len(failed) >= 1
 
+    def test_boundary_action_no_inputs_passes(self):
+        """BoundaryAction blocks have no inputs by design — G-002 should pass."""
+        sys = SystemIR(
+            name="Test",
+            blocks=[
+                BlockIR(
+                    name="Sensor",
+                    block_type="boundary",
+                    signature=("", "Temperature", "", ""),
+                ),
+            ],
+            wirings=[],
+        )
+        findings = check_g002_signature_completeness(sys)
+        assert len(findings) == 1
+        assert findings[0].passed
+
+    def test_boundary_action_no_outputs_still_fails(self):
+        """BoundaryAction with no outputs should still fail G-002."""
+        sys = SystemIR(
+            name="Test",
+            blocks=[
+                BlockIR(
+                    name="BadBoundary",
+                    block_type="boundary",
+                    signature=("", "", "", ""),
+                ),
+            ],
+            wirings=[],
+        )
+        findings = check_g002_signature_completeness(sys)
+        assert len(findings) == 1
+        assert not findings[0].passed
+
+    def test_non_boundary_no_inputs_still_fails(self):
+        """Non-boundary blocks without inputs should still fail G-002."""
+        sys = SystemIR(
+            name="Test",
+            blocks=[
+                BlockIR(
+                    name="Orphan",
+                    block_type="policy",
+                    signature=("", "Signal", "", ""),
+                ),
+            ],
+            wirings=[],
+        )
+        findings = check_g002_signature_completeness(sys)
+        assert len(findings) == 1
+        assert not findings[0].passed
+
 
 # ── G-003: Direction consistency ─────────────────────────────