project workflow state -> output

src/wf_artifacts/drafts/adapter.py

@@ -21,9 +21,8 @@ from .models import (
 def build_workflow_from_draft(draft: WorkflowDraft) -> Workflow:
     """Adapt one typed draft through `WorkflowBuilder` into a core workflow.
 
-    Draft step `output` bindings become node-output-to-state writes. Final
-    workflow output projection stays in core runtime and uses output schema
-    property names as state keys.
+    Draft step `output` bindings become node-output-to-state writes. Draft
+    top-level `output` bindings become core root workflow output projection.
     """
     builder = WorkflowBuilder(
         name=draft.name,
@@ -39,7 +38,8 @@ def build_workflow_from_draft(draft: WorkflowDraft) -> Workflow:
     for source_id, routes in draft.routes.items():
         for outcome, target in routes.items():
             builder.connect(step_refs[source_id], outcome, target)
-    return builder.compile()
+    workflow = builder.compile()
+    return workflow.model_copy(update={"output": list(draft.output)})
 
 
 def _add_step(builder: WorkflowBuilder, step_id: str, step: DraftStep):

src/wf_artifacts/drafts/models.py

@@ -30,9 +30,8 @@ STEP_KIND_KEYS = frozenset(
 class DraftUseStep(BaseModel):
     """Draft step that calls one externally resolvable workflow capability.
 
-    `output` writes node-local output fields into workflow state. It does not
-    define final workflow output; core currently projects final output from
-    state keys whose names match `WorkflowDraft.output_schema.properties`.
+    `output` writes node-local output fields into workflow state. Root
+    workflow output bindings live on `WorkflowDraft.output`.
     """
 
     model_config = ConfigDict(extra="forbid", populate_by_name=True)
@@ -277,16 +276,16 @@ DraftStep = (
 class WorkflowDraft(BaseModel):
     """Patch-friendly JSON authoring document for one workflow graph.
 
-    There is intentionally no top-level output map in this draft shape. Final
-    workflow output is projected from state by matching output-schema property
-    names, so terminal steps should write required output fields to same-named
-    state paths.
+    Step `output` writes node results into state. Top-level `output` projects
+    final workflow output from graph paths. If top-level `output` is empty, core
+    falls back to same-name top-level state projection.
     """
 
     name: str
     input_schema: JsonObject
     state_schema: JsonObject
     output_schema: JsonObject
+    output: list[InputBinding] = Field(default_factory=list)
     start: str
     steps: dict[str, DraftStep]
     routes: dict[str, dict[str, str]] = Field(default_factory=dict)