[Evals API] [1/n] Initial API (#287)

* type system api

* datasets api

* fix

* datasetio api

* kill reward scoring

* scoring functions + evals

* move jobs, fix errors

llama_stack/apis/scoring_functions/__init__.py

@@ -0,0 +1,7 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from .scoring_functions import *  # noqa: F401 F403

llama_stack/apis/scoring_functions/scoring_functions.py

@@ -0,0 +1,88 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from typing import (
+    Any,
+    Dict,
+    List,
+    Literal,
+    Optional,
+    Protocol,
+    runtime_checkable,
+    Union,
+)
+
+from llama_models.schema_utils import json_schema_type, webmethod
+from pydantic import BaseModel, Field
+from typing_extensions import Annotated
+
+from llama_stack.apis.common.type_system import ParamType
+
+
+@json_schema_type
+class Parameter(BaseModel):
+    name: str
+    type: ParamType
+    description: Optional[str] = None
+
+
+# Perhaps more structure can be imposed on these functions. Maybe they could be associated
+# with standard metrics so they can be rolled up?
+
+
+@json_schema_type
+class CommonDef(BaseModel):
+    name: str
+    description: Optional[str] = None
+    metadata: Dict[str, Any] = Field(
+        default_factory=dict,
+        description="Any additional metadata for this definition",
+    )
+    # Hack: same with memory_banks for union defs
+    provider_id: str = ""
+
+
+@json_schema_type
+class DeterministicFunctionDef(CommonDef):
+    type: Literal["deterministic"] = "deterministic"
+    parameters: List[Parameter] = Field(
+        description="List of parameters for the deterministic function",
+    )
+    return_type: ParamType = Field(
+        description="The return type of the deterministic function",
+    )
+    # We can optionally add information here to support packaging of code, etc.
+
+
+@json_schema_type
+class LLMJudgeFunctionDef(CommonDef):
+    type: Literal["judge"] = "judge"
+    model: str = Field(
+        description="The LLM model to use for the judge function",
+    )
+
+
+ScoringFunctionDef = Annotated[
+    Union[DeterministicFunctionDef, LLMJudgeFunctionDef], Field(discriminator="type")
+]
+
+ScoringFunctionDefWithProvider = ScoringFunctionDef
+
+
+@runtime_checkable
+class ScoringFunctions(Protocol):
+    @webmethod(route="/scoring_functions/list", method="GET")
+    async def list_scoring_functions(self) -> List[ScoringFunctionDefWithProvider]: ...
+
+    @webmethod(route="/scoring_functions/get", method="GET")
+    async def get_scoring_function(
+        self, name: str
+    ) -> Optional[ScoringFunctionDefWithProvider]: ...
+
+    @webmethod(route="/scoring_functions/register", method="POST")
+    async def register_scoring_function(
+        self, function: ScoringFunctionDefWithProvider
+    ) -> None: ...