feat: complete draft step model parity

src/wf_artifacts/drafts/__init__.py

@@ -14,6 +14,7 @@ from .models import (
     DraftJoinStep,
     DraftMatchCase,
     DraftMatchStep,
+    DraftSubgraphStep,
     DraftUseStep,
     DraftWhenStep,
     WorkflowDraft,
@@ -29,6 +30,7 @@ __all__ = [
     "DraftJoinStep",
     "DraftMatchCase",
     "DraftMatchStep",
+    "DraftSubgraphStep",
     "DraftWhenStep",
     "DraftUseStep",
     "WorkflowDraft",

src/wf_artifacts/drafts/adapter.py

@@ -1,8 +1,10 @@
 from __future__ import annotations
 
+from typing import Any
+
 from wf_authoring import WorkflowBuilder
 from wf_authoring.dsl import PathExpr
-from wf_core import JoinNode, Workflow
+from wf_core import JoinNode, SubgraphNode, Workflow
 from wf_core.paths import GraphSourcePath
 
 from .models import (
@@ -13,6 +15,7 @@ from .models import (
     DraftJoinStep,
     DraftMatchStep,
     DraftStep,
+    DraftSubgraphStep,
     DraftUseStep,
     DraftWhenStep,
     WorkflowDraft,
@@ -63,12 +66,23 @@ def _add_step(builder: WorkflowBuilder, step_id: str, step: DraftStep):
             concurrent=step.foreach.concurrent,
         )
     if isinstance(step, DraftInterruptStep):
+        interrupt_kwargs: dict[str, Any] = {
+            "id": step_id,
+            "kind": step.interrupt.kind,
+            "request": step.interrupt.request,
+            "resume": step.interrupt.resume,
+            "outcomes": step.interrupt.outcomes,
+        }
+        if step.interrupt.request_schema is not None:
+            interrupt_kwargs["request_schema"] = step.interrupt.request_schema.model_dump(
+                mode="json", exclude_none=True
+            )
+        if step.interrupt.resume_schema is not None:
+            interrupt_kwargs["resume_schema"] = step.interrupt.resume_schema.model_dump(
+                mode="json", exclude_none=True
+            )
         return builder.interrupt(
-            id=step_id,
-            kind=step.interrupt.kind,
-            request=step.interrupt.request,
-            resume=step.interrupt.resume,
-            outcomes=step.interrupt.outcomes,
+            **interrupt_kwargs,
         )
     if isinstance(step, DraftJoinStep):
         node = JoinNode(id=step_id, type="join")
@@ -96,4 +110,12 @@ def _add_step(builder: WorkflowBuilder, step_id: str, step: DraftStep):
             id=step_id,
             default=step.match.default,
         ).entry
+    if isinstance(step, DraftSubgraphStep):
+        node = SubgraphNode(
+            id=step_id,
+            type="subgraph",
+            **step.subgraph.model_dump(),
+        )
+        builder.nodes.append(node)
+        return node
     raise TypeError(f"unsupported draft step {type(step)!r}")

src/wf_artifacts/drafts/models.py

@@ -2,15 +2,17 @@ from __future__ import annotations
 
 from typing import Any, Literal
 
-from pydantic import BaseModel, ConfigDict, Field, model_validator
+from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator
 
 from wf_core.models.conditions import Condition
+from wf_core.models.schemas import SchemaRef
 from wf_core.models.steps import (
     ForeachConcurrentPolicy,
     ForeachItemErrorPolicy,
     InputBinding,
     OutputBinding,
 )
+from wf_core.models.workflow_refs import WorkflowRef
 from wf_core.paths import GraphSourcePath
 
 JsonObject = dict[str, Any]
@@ -24,6 +26,7 @@ STEP_KIND_KEYS = frozenset(
         "when",
         "choose",
         "match",
+        "subgraph",
     }
 )
 
@@ -153,8 +156,18 @@ class DraftInterruptPayload(BaseModel):
     kind: str
     request: list[InputBinding] = Field(default_factory=list)
     resume: list[OutputBinding] = Field(default_factory=list)
+    request_schema: SchemaRef | None = None
+    resume_schema: SchemaRef | None = None
     outcomes: list[str] = Field(default_factory=lambda: ["submitted"])
 
+    @field_validator("request_schema", "resume_schema")
+    @classmethod
+    def _require_object_schema(cls, value: SchemaRef | None) -> SchemaRef | None:
+        """Keep explicit interrupt contracts distinct from untyped interrupts."""
+        if value is not None and value.type != "object":
+            raise ValueError("interrupt schema must describe a JSON object")
+        return value
+
     @model_validator(mode="before")
     @classmethod
     def _coerce_legacy_maps(cls, data: object) -> object:
@@ -184,6 +197,30 @@ class DraftInterruptStep(BaseModel):
     interrupt: DraftInterruptPayload
 
 
+class DraftSubgraphPayload(BaseModel):
+    """Declarative boundary contract for a referenced child workflow."""
+
+    model_config = ConfigDict(extra="forbid")
+
+    workflow: WorkflowRef
+    desc: str | None = None
+    input_schema: SchemaRef = Field(default_factory=lambda: SchemaRef(type="object"))
+    output_schema: SchemaRef = Field(
+        default_factory=lambda: SchemaRef(type="object")
+    )
+    input: list[InputBinding] = Field(default_factory=list)
+    output: list[OutputBinding] = Field(default_factory=list)
+    outcomes: list[str] = Field(default_factory=lambda: ["ok"], min_length=1)
+
+
+class DraftSubgraphStep(BaseModel):
+    """Draft step that lowers to a native `SubgraphNode` boundary."""
+
+    model_config = ConfigDict(extra="forbid")
+
+    subgraph: DraftSubgraphPayload
+
+
 class DraftJoinStep(BaseModel):
     """Draft step that emits the current core join node."""
 
@@ -292,6 +329,7 @@ DraftStep = (
     | DraftWhenStep
     | DraftChooseStep
     | DraftMatchStep
+    | DraftSubgraphStep
 )