yang rui c814943215
feat(extensions): grant bounded host model invocation (#5796)
* feat(extensions): grant bounded host model invocation

* fix(extensions): retain model budgets and isolate schema validation

* fix(extensions): normalize provider-origin model cancellation

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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
2026-09-25 15:24:09 +08:00

71 lines
2.1 KiB
Python

"""Provider-neutral, non-streaming text model calls granted by the host."""
from __future__ import annotations
from collections.abc import Mapping, Sequence
from dataclasses import dataclass
from typing import Literal, Protocol
class ModelInvocationError(RuntimeError):
"""Normalized host error; contains no provider exception or credentials."""
class ModelInvocationUnavailable(ModelInvocationError):
"""The capability has stopped or its configured model is unavailable."""
class ModelInvocationUnauthorized(ModelInvocationError):
"""The requested logical role is not granted to this installation."""
class ModelInvocationFailed(ModelInvocationError):
"""The invocation failed, exceeded a host limit or timed out."""
class ModelOutputValidationError(ModelInvocationFailed):
"""Provider output could not be parsed or validated against the schema."""
@dataclass(frozen=True)
class ModelMessage:
role: Literal["system", "user", "assistant"]
content: str
@dataclass(frozen=True)
class ModelInvocationRequest:
messages: Sequence[ModelMessage]
model_role: str | None = None
purpose: str | None = None
response_schema: Mapping[str, object] | None = None
timeout_seconds: float | None = None
def __post_init__(self) -> None:
object.__setattr__(self, "messages", tuple(self.messages))
@dataclass(frozen=True)
class ModelUsage:
input_tokens: int | None = None
output_tokens: int | None = None
total_tokens: int | None = None
@dataclass(frozen=True)
class ModelInvocationResult:
content: str
structured_output: Mapping[str, object] | None = None
resolved_model: str | None = None
usage: ModelUsage | None = None
class ModelInvoker(Protocol):
async def invoke(self, request: ModelInvocationRequest) -> ModelInvocationResult:
"""Invoke once; schema requests succeed only with validated object data.
Caller cancellation propagates as asyncio.CancelledError. A timeout
(including time waiting for host capacity) raises ModelInvocationFailed.
"""
raise ModelInvocationUnavailable("Model invocation is not supported by this host")