feat: add neutral workflow config models

src/wf_config/__init__.py

@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from .models import (
+    ClientConfig,
+    FilesystemStoreConfig,
+    LocalTargetConfig,
+    RpcHttpTargetConfig,
+    RpcHttpTransportConfig,
+    ServerConfig,
+    StdlibSourceConfig,
+    WorkflowConfigFile,
+)
+
+__all__ = [
+    "ClientConfig",
+    "FilesystemStoreConfig",
+    "LocalTargetConfig",
+    "RpcHttpTargetConfig",
+    "RpcHttpTransportConfig",
+    "ServerConfig",
+    "StdlibSourceConfig",
+    "WorkflowConfigFile",
+]

src/wf_config/models.py

@@ -0,0 +1,95 @@
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Annotated, Literal
+
+from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator
+
+
+class WorkflowConfigModel(BaseModel):
+    """Base config model: reject typos so config mistakes fail fast."""
+
+    model_config = ConfigDict(extra="forbid")
+
+
+class LocalTargetConfig(WorkflowConfigModel):
+    kind: Literal["local"] = "local"
+
+
+class RpcHttpTargetConfig(WorkflowConfigModel):
+    kind: Literal["rpc_http"]
+    url: str
+    timeout_seconds: float = Field(default=30.0, gt=0)
+
+
+TargetConfig = Annotated[
+    LocalTargetConfig | RpcHttpTargetConfig,
+    Field(discriminator="kind"),
+]
+
+
+class ClientConfig(WorkflowConfigModel):
+    target: TargetConfig = Field(default_factory=LocalTargetConfig)
+
+
+class FilesystemStoreConfig(WorkflowConfigModel):
+    kind: Literal["filesystem"] = "filesystem"
+    root: Path = Path(".wf_store")
+
+
+StoreConfig = Annotated[
+    FilesystemStoreConfig,
+    Field(discriminator="kind"),
+]
+
+
+class RpcHttpTransportConfig(WorkflowConfigModel):
+    kind: Literal["rpc_http"]
+    host: str = "127.0.0.1"
+    port: int = Field(default=8765, ge=1, le=65535)
+    path: str = "/rpc"
+
+    @field_validator("path")
+    @classmethod
+    def validate_path(cls, value: str) -> str:
+        if not value.startswith("/"):
+            raise ValueError("transport path must start with '/'")
+        return value
+
+
+ServerTransportConfig = Annotated[
+    RpcHttpTransportConfig,
+    Field(discriminator="kind"),
+]
+
+
+class StdlibSourceConfig(WorkflowConfigModel):
+    kind: Literal["stdlib"]
+    id: str = Field(min_length=1)
+
+
+SourceConfig = Annotated[
+    StdlibSourceConfig,
+    Field(discriminator="kind"),
+]
+
+
+class ServerConfig(WorkflowConfigModel):
+    store: StoreConfig = Field(default_factory=FilesystemStoreConfig)
+    transports: list[ServerTransportConfig] = Field(default_factory=list)
+    sources: list[SourceConfig] = Field(default_factory=list)
+
+    @model_validator(mode="after")
+    def validate_unique_source_ids(self) -> ServerConfig:
+        seen: set[str] = set()
+        for source in self.sources:
+            if source.id in seen:
+                raise ValueError(f"duplicate source id {source.id!r}")
+            seen.add(source.id)
+        return self
+
+
+class WorkflowConfigFile(WorkflowConfigModel):
+    version: Literal[1] = 1
+    client: ClientConfig = Field(default_factory=ClientConfig)
+    server: ServerConfig = Field(default_factory=ServerConfig)