feat: add draft step capability helper

src/wf_transport_rpc_http/__init__.py

@@ -4,6 +4,7 @@ from .app import create_rpc_app
 from .client import RpcWorkflowApiClient
 from .errors import WorkflowRpcError
 from .models import (
+    AddStepFromCapabilityParams,
     AdminEmptyParams,
     CallCapabilityParams,
     CreateArtifactFromPlanParams,
@@ -43,6 +44,7 @@ from .models import (
 __all__ = [
     "CreateArtifactFromPlanParams",
     "CreateArtifactFromWorkspaceParams",
+    "AddStepFromCapabilityParams",
     "AdminEmptyParams",
     "CallCapabilityParams",
     "CreateDraftFromCapabilityParams",

src/wf_transport_rpc_http/client/drafts.py

@@ -181,6 +181,36 @@ class RpcDraftClientMixin:
             },
         )
 
+    async def add_step_from_capability(
+        self: RpcCaller,
+        *,
+        workspace_id: str,
+        revision: int,
+        step_id: str,
+        capability_name: str,
+        route_from_step: str | None = None,
+        route_from_outcome: str = "ok",
+        route_outcome: str = "ok",
+        route_to: str = "__end__",
+        input_map: dict[str, str] | None = None,
+        bind_outputs: dict[str, str] | None = None,
+    ) -> dict[str, Any]:
+        return await self._call(
+            "workflow.draft_workspaces.add_step_from_capability",
+            {
+                "workspace_id": workspace_id,
+                "revision": revision,
+                "step_id": step_id,
+                "capability_name": capability_name,
+                "route_from_step": route_from_step,
+                "route_from_outcome": route_from_outcome,
+                "route_outcome": route_outcome,
+                "route_to": route_to,
+                "input_map": input_map or {},
+                "bind_outputs": bind_outputs or {},
+            },
+        )
+
     async def validate_draft_workspace(
         self: RpcCaller,
         *,

src/wf_transport_rpc_http/methods/drafts.py

@@ -9,6 +9,7 @@ from wf_server import WorkflowServer
 from ..errors import WorkflowRpcError, raise_workflow_rpc_error
 from ..models import (
     AddStateFromOutputParams,
+    AddStepFromCapabilityParams,
     BindOutputToStateParams,
     CreateArtifactFromWorkspaceParams,
     CreateDraftFromCapabilityParams,
@@ -215,6 +216,29 @@ def register_methods(
         except (ValueError, KeyError, LookupError, FileNotFoundError) as exc:
             raise_workflow_rpc_error(exc)
 
+    @entrypoint.method(
+        name="workflow.draft_workspaces.add_step_from_capability",
+        errors=[WorkflowRpcError],
+    )
+    async def workflow_draft_workspaces_add_step_from_capability(
+        params: AddStepFromCapabilityParams = RpcParams(),
+    ) -> dict[str, Any]:
+        try:
+            return await server.api.add_step_from_capability(
+                workspace_id=params.workspace_id,
+                revision=params.revision,
+                step_id=params.step_id,
+                capability_name=params.capability_name,
+                route_from_step=params.route_from_step,
+                route_from_outcome=params.route_from_outcome,
+                route_outcome=params.route_outcome,
+                route_to=params.route_to,
+                input_map=params.input_map,
+                bind_outputs=params.bind_outputs,
+            )
+        except (ValueError, KeyError, LookupError, FileNotFoundError) as exc:
+            raise_workflow_rpc_error(exc)
+
     @entrypoint.method(
         name="workflow.draft_workspaces.validate", errors=[WorkflowRpcError]
     )

src/wf_transport_rpc_http/models.py

@@ -157,6 +157,19 @@ class BindOutputToStateParams(RpcParamsModel):
     state_path: str = Field(min_length=1)
 
 
+class AddStepFromCapabilityParams(RpcParamsModel):
+    workspace_id: str = Field(min_length=1)
+    revision: int = Field(ge=1)
+    step_id: str = Field(min_length=1)
+    capability_name: str = Field(min_length=1)
+    route_from_step: str | None = None
+    route_from_outcome: str = Field(default="ok", min_length=1)
+    route_outcome: str = Field(default="ok", min_length=1)
+    route_to: str = Field(default="__end__", min_length=1)
+    input_map: dict[str, str] = Field(default_factory=dict)
+    bind_outputs: dict[str, str] = Field(default_factory=dict)
+
+
 class ValidateDraftWorkspaceParams(RpcParamsModel):
     workspace_id: str = Field(min_length=1)