refactor: add static source provider seam

src/wf_server/config.py

@@ -3,9 +3,9 @@ from __future__ import annotations
 from pathlib import Path
 
 from wf_config import FilesystemStoreConfig, PythonSourceConfig, WorkflowConfigFile
-from wf_platform import CapabilitySource
 
 from .context import WorkflowServer, build_local_static_workflow_server
+from .sources import WorkflowSourceProvider, collect_static_sources
 
 
 def _has_mcp_sources(config: WorkflowConfigFile) -> bool:
@@ -14,20 +14,20 @@ def _has_mcp_sources(config: WorkflowConfigFile) -> bool:
     )
 
 
-def _python_sources(config: WorkflowConfigFile) -> dict[str, CapabilitySource]:
-    from wf_sources_python import load_python_source
-
-    return {
-        source.id: load_python_source(
-            source_id=source.id,
-            path=source.path,
-            module=source.module,
-            registry=source.registry,
-            enabled=source.enabled,
-        )
+def _static_source_providers(
+    config: WorkflowConfigFile,
+) -> list[WorkflowSourceProvider]:
+    providers: list[WorkflowSourceProvider] = []
+    python_configs = [
+        source
         for source in config.server.sources
         if isinstance(source, PythonSourceConfig)
-    }
+    ]
+    if python_configs:
+        from wf_sources_python import PythonSourceProvider
+
+        providers.append(PythonSourceProvider(python_configs))
+    return providers
 
 
 def _build_mcp_workflow_server_from_workflow_config(
@@ -68,7 +68,7 @@ def build_workflow_server_from_workflow_config(
         raise ValueError("wf-rpc-server currently requires filesystem store")
     return build_local_static_workflow_server(
         store.root,
-        extra_sources=_python_sources(config),
+        extra_sources=collect_static_sources(_static_source_providers(config)),
     )
 
 

src/wf_server/sources.py

@@ -0,0 +1,48 @@
+from __future__ import annotations
+
+from collections.abc import Mapping, Sequence
+from dataclasses import dataclass
+from typing import Protocol
+
+from wf_platform import CapabilitySource
+
+
+class WorkflowSourceProvider(Protocol):
+    """Static source inventory provider for server composition.
+
+    This seam is intentionally narrow: providers return workflow-facing
+    `CapabilitySource` objects. Runtime pools, admin/apply hooks, and live
+    health checks remain separate provider-specific concerns.
+    """
+
+    def load_sources(self) -> Mapping[str, CapabilitySource]: ...
+
+
+@dataclass(frozen=True, slots=True)
+class StaticSourceProvider:
+    """Adapter for already-materialized capability sources."""
+
+    sources: Mapping[str, CapabilitySource]
+
+    def load_sources(self) -> Mapping[str, CapabilitySource]:
+        return dict(self.sources)
+
+
+def collect_static_sources(
+    providers: Sequence[WorkflowSourceProvider],
+) -> dict[str, CapabilitySource]:
+    """Merge static provider inventories while rejecting ambiguous source ids."""
+    collected: dict[str, CapabilitySource] = {}
+    for provider in providers:
+        for source_id, source in provider.load_sources().items():
+            if source_id in collected:
+                raise ValueError(f"duplicate workflow source ids: {[source_id]}")
+            collected[source_id] = source
+    return collected
+
+
+__all__ = [
+    "StaticSourceProvider",
+    "WorkflowSourceProvider",
+    "collect_static_sources",
+]