capabilityref: less string matching more model

docs/workflow_artifacts.md

@@ -571,12 +571,11 @@ concrete source but leaves the saved artifact immutable. Concrete node names
 such as `demo.personal.echo_tool` remain supported for raw local plans and older
 artifacts.
 
-Implementation note: these references are currently parsed from strings with
-dot-separated source and capability names. That keeps the wire format simple but
-leaks path logic into runtime code. A future cleanup should introduce typed
-reference objects, such as `CapabilityRef(logical_source, capability_name)` and
-`BoundCapabilityRef(concrete_source, capability_name)`, and leave dot-joined
-strings as presentation and serialization only.
+Implementation note: source and capability names now have segment-backed
+platform refs: `SourceRef(parts=...)` and `CapabilityRef(source=..., name=...)`.
+Dot-joined names remain the wire/presentation format, but new runtime code
+should parse or format through those refs instead of rediscovering source/name
+boundaries with ad hoc string splits.
 
 The first implementation should prefer artifact validation and dependency
 diagnostics before attempting persistent nested resume.

src/wf_artifacts/factory.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 from collections.abc import Mapping
 
 from wf_core import ReducerRef, Workflow
+from wf_platform import CapabilityRef
 
 from .models import ArtifactKind, JsonObject, RequiredCapability, WorkflowArtifact
 from .references import normalize_plan_node_refs
@@ -101,14 +102,13 @@ def _required_reducers_from_plan(plan: JsonObject) -> dict[str, RequiredCapabili
                 reducer = ReducerRef.model_validate(reducer_payload)
             except ValueError:
                 continue
-        if "." not in reducer.name:
+        try:
+            reducer_ref = CapabilityRef.parse(reducer.name)
+        except ValueError:
             continue
-        if "." not in reducer.name:
-            continue
-        logical_source, _, capability_name = reducer.name.rpartition(".")
         requirements[reducer.name] = RequiredCapability(
-            logical_source=logical_source,
-            capability_name=capability_name,
+            logical_source=str(reducer_ref.source),
+            capability_name=reducer_ref.name,
             kind="reducer",
         )
     return requirements

src/wf_artifacts/references.py

@@ -3,6 +3,8 @@ from __future__ import annotations
 from collections.abc import Mapping
 from copy import deepcopy
 
+from wf_platform import CapabilityRef, SourceRef
+
 from .models import JsonObject, RequiredCapability
 
 
@@ -68,6 +70,8 @@ def logical_ref_for_concrete_ref(
         capability_name = concrete_ref[len(prefix) :]
         if not capability_name:
             continue
-        logical_ref = f"{logical_source}.{capability_name}"
+        logical_ref = str(
+            CapabilityRef(source=SourceRef.parse(logical_source), name=capability_name)
+        )
         return logical_ref, logical_source, capability_name, concrete_source
     return None

src/wf_mcp/workflow_surface/handlers.py

@@ -15,6 +15,7 @@ from wf_artifacts import (
     create_workflow_artifact_from_plan as build_workflow_artifact_from_plan,
     validate_deployment_dependencies,
 )
+from wf_platform import CapabilityRef
 from wf_authoring import build_async_registry
 from wf_core import RuntimeContext
 
@@ -316,21 +317,23 @@ def _available_sources(service: WfMcpService) -> list[AvailableSource]:
     sources: list[AvailableSource] = []
     for source in service.capability_sources.values():
         capabilities = {
-            spec.name.rsplit(".", maxsplit=1)[-1]: AvailableCapability(
-                name=spec.name.rsplit(".", maxsplit=1)[-1],
+            capability_name: AvailableCapability(
+                name=capability_name,
                 kind="node_spec",
                 input_schema_hash=None,
                 output_schema_hash=None,
             )
             for spec in source.capabilities.node_specs.values()
+            if (capability_name := _capability_name(spec.name)) is not None
         }
         capabilities.update(
             {
-                reducer.name.rsplit(".", maxsplit=1)[-1]: AvailableCapability(
-                    name=reducer.name.rsplit(".", maxsplit=1)[-1],
+                capability_name: AvailableCapability(
+                    name=capability_name,
                     kind="reducer",
                 )
                 for reducer in source.capabilities.reducers.values()
+                if (capability_name := _capability_name(reducer.name)) is not None
             }
         )
         sources.append(
@@ -343,6 +346,14 @@ def _available_sources(service: WfMcpService) -> list[AvailableSource]:
     return sources
 
 
+def _capability_name(qualified_name: str) -> str | None:
+    """Return the local name of one qualified capability ref if it is valid."""
+    try:
+        return CapabilityRef.parse(qualified_name).name
+    except ValueError:
+        return None
+
+
 def _artifact_capability_id(artifact: WorkflowArtifact) -> str:
     """Use the same stable name shape as workflow artifact catalog entries."""
     return f"workflow.{artifact.id}.v{artifact.version}"

src/wf_mcp/workflow_surface/runtime_dependencies.py

@@ -6,7 +6,7 @@ from typing import Any
 from wf_artifacts import RequiredCapability, WorkflowArtifact, WorkflowDeployment
 from wf_authoring import AsyncRegistryHandler, NodeSpec, build_async_registry
 from wf_core.runtime.ops.merges import ReducerDefinition
-from wf_platform import CapabilitySource
+from wf_platform import CapabilityRef, CapabilitySource
 
 
 @dataclass(frozen=True, slots=True)
@@ -67,11 +67,12 @@ def _resolve_node_spec(
         return node_name, concrete
 
     if deployment is not None:
-        logical_source, separator, capability_name = node_name.rpartition(".")
-        if separator:
-            bound_source_id = deployment.bindings.get(logical_source)
-            if bound_source_id is not None:
-                bound_name = f"{bound_source_id}.{capability_name}"
+        try:
+            bound_ref = CapabilityRef.parse(node_name).bind(deployment.bindings)
+        except ValueError:
+            bound_ref = None
+        if bound_ref is not None:
+            bound_name = str(bound_ref)
             concrete = _find_node_spec(bound_name, sources)
             if concrete is not None:
                 return bound_name, concrete
@@ -124,6 +125,10 @@ def _find_reducer_definition(
     capability_name: str,
 ) -> ReducerDefinition | None:
     for reducer_name, definition in source.capabilities.reducer_definitions.items():
-        if reducer_name.rsplit(".", maxsplit=1)[-1] == capability_name:
+        try:
+            reducer_ref = CapabilityRef.parse(reducer_name)
+        except ValueError:
+            continue
+        if reducer_ref.name == capability_name:
             return definition
     return None

src/wf_platform/__init__.py

@@ -1,3 +1,4 @@
+from .refs import CapabilityRef, SourceRef
 from .sources import (
     CapabilityBuckets,
     CapabilitySource,
@@ -14,6 +15,7 @@ from .sources import (
 __all__ = [
     "CapabilityBuckets",
     "CapabilitySource",
+    "CapabilityRef",
     "SourceCapabilityInventory",
     "SourceInventory",
     "SourceKind",
@@ -22,4 +24,5 @@ __all__ = [
     "SourceStatus",
     "SourceVisibility",
     "SourceVisibilitySnapshot",
+    "SourceRef",
 ]

src/wf_platform/refs.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+from collections.abc import Mapping
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True, slots=True)
+class SourceRef:
+    """Segment-backed source identifier with dotted-string wire formatting."""
+
+    parts: tuple[str, ...]
+
+    def __post_init__(self) -> None:
+        if not self.parts or any(not part for part in self.parts):
+            raise ValueError("source ref requires non-empty path segments")
+
+    @classmethod
+    def parse(cls, value: str) -> SourceRef:
+        """Parse one dotted source id into first-class path segments."""
+        return cls(tuple(value.split(".")))
+
+    def __str__(self) -> str:
+        return ".".join(self.parts)
+
+
+@dataclass(frozen=True, slots=True)
+class CapabilityRef:
+    """Segment-backed capability reference: one source plus one local name."""
+
+    source: SourceRef
+    name: str
+
+    def __post_init__(self) -> None:
+        if not self.name:
+            raise ValueError("capability ref requires a non-empty name")
+
+    @classmethod
+    def parse(cls, value: str) -> CapabilityRef:
+        """Parse `<source>.<capability>` while preserving source path segments."""
+        source_text, separator, name = value.rpartition(".")
+        if not separator or not source_text or not name:
+            raise ValueError("capability ref requires source and capability segments")
+        return cls(source=SourceRef.parse(source_text), name=name)
+
+    def bind(self, bindings: Mapping[str, str]) -> CapabilityRef:
+        """Replace a logical source with its concrete bound source when present."""
+        bound_source = bindings.get(str(self.source))
+        if bound_source is None:
+            return self
+        return CapabilityRef(source=SourceRef.parse(bound_source), name=self.name)
+
+    def __str__(self) -> str:
+        return f"{self.source}.{self.name}"

tests/platform/test_refs.py

@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+from wf_platform import CapabilityRef, SourceRef
+
+
+def test_source_ref_round_trips_segmented_names() -> None:
+    source = SourceRef.parse("demo.personal")
+
+    assert source.parts == ("demo", "personal")
+    assert str(source) == "demo.personal"
+
+
+def test_capability_ref_round_trips_segmented_names() -> None:
+    ref = CapabilityRef.parse("demo.personal.echo_tool")
+
+    assert ref.source.parts == ("demo", "personal")
+    assert ref.name == "echo_tool"
+    assert str(ref) == "demo.personal.echo_tool"
+
+
+def test_capability_ref_binds_logical_source_to_concrete_source() -> None:
+    ref = CapabilityRef.parse("demo.echo_tool")
+
+    bound = ref.bind({"demo": "demo.personal"})
+
+    assert str(bound) == "demo.personal.echo_tool"
+
+
+def test_capability_ref_rejects_missing_capability_name() -> None:
+    try:
+        CapabilityRef.parse("demo")
+    except ValueError as exc:
+        assert "source and capability" in str(exc)
+    else:
+        raise AssertionError("expected invalid capability ref to be rejected")