get end node support in builder and drafts

tests/artifacts/test_draft_adapter.py

@@ -5,7 +5,7 @@ from pydantic import ValidationError
 from wf_artifacts.drafts import WorkflowDraft
 from wf_artifacts.drafts.api import compile_workflow_draft, validate_workflow_draft
 from wf_artifacts.drafts.adapter import build_workflow_from_draft
-from wf_core import ConditionNode, ForeachNode, NodeUse
+from wf_core import ConditionNode, EndNode, ForeachNode, NodeUse
 from wf_core.models.steps import InputValueBinding
 
 
@@ -213,6 +213,33 @@ def test_adapter_lowers_when_step_through_builder() -> None:
     ]
 
 
+def test_adapter_lowers_explicit_end_step() -> None:
+    draft = WorkflowDraft.model_validate(
+        {
+            "name": "end_example",
+            "input_schema": {},
+            "state_schema": {"fields": {}},
+            "output_schema": {},
+            "outcomes": ["ok", "error"],
+            "start": "echo",
+            "steps": {
+                "echo": {"use": "demo.echo"},
+                "end_error": {"end": {"outcome": "error"}},
+            },
+            "routes": {"echo": {"error": "end_error"}},
+        }
+    )
+
+    workflow = build_workflow_from_draft(draft)
+    terminal = workflow.nodes[1]
+
+    assert isinstance(terminal, EndNode)
+    assert terminal.id == "end_error"
+    assert terminal.outcome == "error"
+    assert workflow.outcomes == ["ok", "error"]
+    assert workflow.edges[0].to == "end_error"
+
+
 def test_adapter_lowers_choose_step_through_builder() -> None:
     draft = WorkflowDraft.model_validate(
         {

tests/artifacts/test_draft_models.py

@@ -7,6 +7,7 @@ from pydantic import ValidationError
 
 from wf_artifacts.drafts import (
     DraftChooseStep,
+    DraftEndStep,
     DraftForeachStep,
     DraftMatchStep,
     DraftUseStep,
@@ -135,6 +136,25 @@ def test_workflow_draft_accepts_when_step() -> None:
     assert isinstance(draft.steps["decide"], DraftWhenStep)
 
 
+def test_workflow_draft_accepts_explicit_end_step() -> None:
+    draft = WorkflowDraft.model_validate(
+        {
+            **_keyed_echo_draft(),
+            "outcomes": ["ok", "error"],
+            "steps": {
+                **_keyed_echo_draft()["steps"],
+                "end_error": {"end": {"outcome": "error"}},
+            },
+            "routes": {"echo": {"error": "end_error"}},
+        }
+    )
+
+    terminal = draft.steps["end_error"]
+
+    assert isinstance(terminal, DraftEndStep)
+    assert terminal.end.outcome == "error"
+
+
 def test_workflow_draft_accepts_choose_step() -> None:
     draft = WorkflowDraft.model_validate(
         {

tests/authoring/test_builder.py

@@ -14,7 +14,7 @@ from wf_authoring import (
     state,
     state_path,
 )
-from wf_core import END, RunStatus, WorkflowExecutionError
+from wf_core import END, EndNode, RunStatus, WorkflowExecutionError
 from wf_core.models.steps import InputPathBinding, InputValueBinding
 from wf_core.paths import GraphSourcePath, LocalPath, StatePath
 from wf_platform import CapabilityRef
@@ -455,6 +455,25 @@ def test_builder_rejects_mixed_canonical_and_deprecated_output_styles() -> None:
         )
 
 
+def test_builder_adds_explicit_end_node() -> None:
+    builder = WorkflowBuilder(
+        name="explicit_end",
+        input_schema={},
+        state_schema={"fields": {}},
+        output_schema={},
+        outcomes=["ok", "error"],
+    )
+
+    terminal = builder.end("error", id="end_error")
+
+    assert isinstance(terminal, EndNode)
+    assert terminal.id == "end_error"
+    assert terminal.outcome == "error"
+    assert builder.nodes[-1] is terminal
+    builder.set_entry_point(terminal)
+    assert builder.compile().outcomes == ["ok", "error"]
+
+
 class _StructuralKeyMap(Mapping[object, object]):
     def __getitem__(self, key: object) -> object:
         raise KeyError(key)