unofficially add wf.std as source

examples/mcp_tool_workflow.py

@@ -55,11 +55,19 @@ async def run_example() -> dict[str, object]:
                 "node": "fixture.personal.echo_tool",
                 "in_map": {"input.text": "text"},
                 "out_map": {"echoed": "state.echoed"},
-            }
+            },
+            {
+                "id": "raise_mcp_error",
+                "type": "node",
+                "node": "wf.std.runtime_error",
+                "in_map": {"input.text": "message"},
+                "out_map": {},
+            },
         ],
         edges=[
             {"from": "echo", "outcome": "ok", "to": END},
-            {"from": "echo", "outcome": "error", "to": END}, # workaround for now; i need wf_authoring.ops::runtime_error
+            {"from": "echo", "outcome": "error", "to": "raise_mcp_error"},
+            {"from": "raise_mcp_error", "outcome": "ok", "to": END},
         ],
     )
 

src/wf_authoring/nodes/decorator.py

@@ -101,6 +101,8 @@ def node(
                 description=description or fn.description,
                 is_async=is_async if is_async is not None else fn.is_async,
                 accepts_context=fn.accepts_context,
+                input_schema_contract=fn.input_schema_contract,
+                output_schema_contract=fn.output_schema_contract,
             )
 
         inferred_input_model: type[BaseModel] | None = input_model

src/wf_authoring/nodes/spec.py

@@ -61,7 +61,9 @@ class NodeSpec(Generic[InputT, OutputT]):
     is_async: bool = False
     accepts_context: bool = True
     input_schema_contract: dict[str, Any] | None = None
+    "enforced schema, if None use input_model"
     output_schema_contract: dict[str, Any] | None = None
+    "enforced schema, if None use output_model"
 
     def __call__(
         self,

src/wf_mcp/broker/service/builtins.py

@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from typing import Any
+
+from wf_authoring import NodeSpec, node, runtime_error
+
+from .specs import qualify_spec
+
+BUILTIN_CONNECTION_ID = "wf.std"
+"""Internal source id for workflow standard-library node specs."""
+
+
+def builtin_specs() -> dict[str, NodeSpec[Any, Any]]:
+    """Return built-in NodeSpecs available to raw broker workflow plans."""
+    specs = [
+        node(
+            runtime_error,
+            name="runtime_error",
+            description="Fail the current workflow branch with a runtime error.",
+        )
+    ]
+    qualified_specs = [qualify_spec(BUILTIN_CONNECTION_ID, spec) for spec in specs]
+    return {spec.name: spec for spec in qualified_specs}

src/wf_mcp/broker/service/core.py

@@ -23,6 +23,7 @@ from ..catalog import CombinedCatalog, snapshot_from_specs
 from ..discovery import discover_connection_capabilities, specs_from_discovered_tools
 from ..events import McpEvent, make_event
 from .adapters import require_adapter
+from .builtins import BUILTIN_CONNECTION_ID, builtin_specs
 from .specs import get_qualified_spec, qualify_spec
 
 
@@ -36,6 +37,12 @@ class WfMcpService:
         default_factory=dict
     )
     events: list[McpEvent] = field(default_factory=list)
+    include_builtin_specs: bool = True
+
+    def __post_init__(self) -> None:
+        """Install broker-local standard-library specs when enabled."""
+        if self.include_builtin_specs:
+            self.specs_by_connection.setdefault(BUILTIN_CONNECTION_ID, builtin_specs())
 
     def register_connection(self, connection: ConnectionConfig) -> None:
         parse_connection_id(connection.id)

tests/fixtures/mcp_echo_server.py

@@ -8,9 +8,11 @@ from pydantic import Field
 
 server = FastMCP("echo-fixture")
 
+
 class EchoToolResult(TypedDict):
     echoed: str
 
+
 @server.tool(title="Echo tool")
 async def echo_tool(
     text: Annotated[str, Field(description="Text to echo")],

tests/rewrite/models.py

@@ -67,7 +67,7 @@ class Context(TypedDict):  # dataclass support? no. i mean langgraph doesnt.
 ### what about us? how should we handle context?
 #
 # in the future if wed like, we could handle context. This could be useful for lda.chat!
-# i want lda.chat to be/have a meta-agent. So i could spin up ideas! a 
+# i want lda.chat to be/have a meta-agent. So i could spin up ideas! a
 
 
 class ContextInput(BaseModel):

tests/wf_mcp/test_service.py

@@ -34,6 +34,22 @@ def test_service_builds_namespaced_catalog() -> None:
     ]
 
 
+def test_service_installs_builtin_stdlib_specs_by_default() -> None:
+    service = WfMcpService(store=FileStore(local_temp_root() / "builtin_store"))
+
+    assert "wf.std" in service.specs_by_connection
+    assert "wf.std.runtime_error" in service.specs_by_connection["wf.std"]
+
+
+def test_service_can_disable_builtin_stdlib_specs() -> None:
+    service = WfMcpService(
+        store=FileStore(local_temp_root() / "no_builtin_store"),
+        include_builtin_specs=False,
+    )
+
+    assert "wf.std" not in service.specs_by_connection
+
+
 def test_service_compiles_and_runs_raw_plan() -> None:
     service = WfMcpService(store=FileStore(local_temp_root() / "run_store"))
     service.register_connection(