reducerspec

src/wf_mcp/broker/service/builtins.py

@@ -4,6 +4,7 @@ from typing import Any, Protocol
 
 from pydantic import BaseModel, Field
 
+from wf_core import ReducerSpec
 from wf_authoring import (
     NodeReturn,
     NodeSpec,
@@ -109,6 +110,25 @@ def builtin_specs() -> dict[str, NodeSpec[Any, Any]]:
     return {spec.name: spec for spec in qualified_specs}
 
 
+def builtin_reducers() -> dict[str, ReducerSpec]:
+    """Return built-in reducers owned by the workflow standard library."""
+    specs = (
+        ReducerSpec(
+            name="wf.std.replace",
+            description="Replace the current state value with the incoming value.",
+        ),
+        ReducerSpec(
+            name="wf.std.append",
+            description="Append one value or many values into a list-valued state path.",
+        ),
+        ReducerSpec(
+            name="wf.std.merge_object",
+            description="Shallow-merge object values at one exact state path.",
+        ),
+    )
+    return {spec.name: spec for spec in specs}
+
+
 def mcp_specs(service: ToolCaller) -> dict[str, NodeSpec[Any, Any]]:
     """Return service-bound MCP utility specs available to raw plans."""
 
@@ -138,7 +158,10 @@ def builtin_sources(service: ToolCaller) -> dict[str, CapabilitySource]:
         BUILTIN_CONNECTION_ID: CapabilitySource(
             id=BUILTIN_CONNECTION_ID,
             kind="system",
-            capabilities=CapabilityBuckets(node_specs=builtin_specs()),
+            capabilities=CapabilityBuckets(
+                node_specs=builtin_specs(),
+                reducers=builtin_reducers(),
+            ),
             visibility=SourceVisibility(
                 planner=True,
                 mcp_client=True,

src/wf_mcp/broker/service/capability_sources.py

@@ -4,6 +4,7 @@ from dataclasses import dataclass, field
 from typing import Any, Literal
 
 from wf_authoring import NodeSpec
+from wf_core import ReducerSpec
 
 SourceKind = Literal["system", "connection"]
 
@@ -27,6 +28,7 @@ class SourcePermissions:
 class CapabilityBuckets:
     tools: dict[str, Any] = field(default_factory=dict)
     node_specs: dict[str, NodeSpec[Any, Any]] = field(default_factory=dict)
+    reducers: dict[str, ReducerSpec] = field(default_factory=dict)
     prompts: dict[str, Any] = field(default_factory=dict)
     resources: dict[str, Any] = field(default_factory=dict)
 
@@ -60,6 +62,7 @@ class CapabilitySource:
             "description": self.description,
             "tool_count": len(self.capabilities.tools),
             "node_spec_count": len(self.capabilities.node_specs),
+            "reducer_count": len(self.capabilities.reducers),
             "prompt_count": len(self.capabilities.prompts),
             "resource_count": len(self.capabilities.resources),
         }
@@ -71,6 +74,7 @@ class CapabilitySource:
             "capabilities": {
                 "tools": sorted(self.capabilities.tools),
                 "node_specs": sorted(self.capabilities.node_specs),
+                "reducers": sorted(self.capabilities.reducers),
                 "prompts": sorted(self.capabilities.prompts),
                 "resources": sorted(self.capabilities.resources),
             },