feat(agent): add streaming groundwork for future TUI

Preserve the provider and agent-loop streaming primitives plus the CLI experiment scaffolding so this work can be resumed later without blocking urgent bug fixes on main.

Made-with: Cursor
This commit is contained in:
Xubin Ren
2026-03-22 02:38:34 +00:00
committed by Xubin Ren
parent 5fd66cae5c
commit e79b9f4a83
5 changed files with 268 additions and 90 deletions

View File

@@ -3,6 +3,7 @@
import asyncio
import json
from abc import ABC, abstractmethod
from collections.abc import Awaitable, Callable
from dataclasses import dataclass, field
from typing import Any
@@ -223,6 +224,90 @@ class LLMProvider(ABC):
except Exception as exc:
return LLMResponse(content=f"Error calling LLM: {exc}", finish_reason="error")
async def chat_stream(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None = None,
model: str | None = None,
max_tokens: int = 4096,
temperature: float = 0.7,
reasoning_effort: str | None = None,
tool_choice: str | dict[str, Any] | None = None,
on_content_delta: Callable[[str], Awaitable[None]] | None = None,
) -> LLMResponse:
"""Stream a chat completion, calling *on_content_delta* for each text chunk.
Returns the same ``LLMResponse`` as :meth:`chat`. The default
implementation falls back to a non-streaming call and delivers the
full content as a single delta. Providers that support native
streaming should override this method.
"""
response = await self.chat(
messages=messages, tools=tools, model=model,
max_tokens=max_tokens, temperature=temperature,
reasoning_effort=reasoning_effort, tool_choice=tool_choice,
)
if on_content_delta and response.content:
await on_content_delta(response.content)
return response
async def _safe_chat_stream(self, **kwargs: Any) -> LLMResponse:
"""Call chat_stream() and convert unexpected exceptions to error responses."""
try:
return await self.chat_stream(**kwargs)
except asyncio.CancelledError:
raise
except Exception as exc:
return LLMResponse(content=f"Error calling LLM: {exc}", finish_reason="error")
async def chat_stream_with_retry(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None = None,
model: str | None = None,
max_tokens: object = _SENTINEL,
temperature: object = _SENTINEL,
reasoning_effort: object = _SENTINEL,
tool_choice: str | dict[str, Any] | None = None,
on_content_delta: Callable[[str], Awaitable[None]] | None = None,
) -> LLMResponse:
"""Call chat_stream() with retry on transient provider failures."""
if max_tokens is self._SENTINEL:
max_tokens = self.generation.max_tokens
if temperature is self._SENTINEL:
temperature = self.generation.temperature
if reasoning_effort is self._SENTINEL:
reasoning_effort = self.generation.reasoning_effort
kw: dict[str, Any] = dict(
messages=messages, tools=tools, model=model,
max_tokens=max_tokens, temperature=temperature,
reasoning_effort=reasoning_effort, tool_choice=tool_choice,
on_content_delta=on_content_delta,
)
for attempt, delay in enumerate(self._CHAT_RETRY_DELAYS, start=1):
response = await self._safe_chat_stream(**kw)
if response.finish_reason != "error":
return response
if not self._is_transient_error(response.content):
stripped = self._strip_image_content(messages)
if stripped is not None:
logger.warning("Non-transient LLM error with image content, retrying without images")
return await self._safe_chat_stream(**{**kw, "messages": stripped})
return response
logger.warning(
"LLM transient error (attempt {}/{}), retrying in {}s: {}",
attempt, len(self._CHAT_RETRY_DELAYS), delay,
(response.content or "")[:120].lower(),
)
await asyncio.sleep(delay)
return await self._safe_chat_stream(**kw)
async def chat_with_retry(
self,
messages: list[dict[str, Any]],

View File

@@ -4,6 +4,7 @@ import hashlib
import os
import secrets
import string
from collections.abc import Awaitable, Callable
from typing import Any
import json_repair
@@ -223,6 +224,64 @@ class LiteLLMProvider(LLMProvider):
clean["tool_call_id"] = map_id(clean["tool_call_id"])
return sanitized
def _build_chat_kwargs(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None,
model: str | None,
max_tokens: int,
temperature: float,
reasoning_effort: str | None,
tool_choice: str | dict[str, Any] | None,
) -> tuple[dict[str, Any], str]:
"""Build the kwargs dict for ``acompletion``.
Returns ``(kwargs, original_model)`` so callers can reuse the
original model string for downstream logic.
"""
original_model = model or self.default_model
resolved = self._resolve_model(original_model)
extra_msg_keys = self._extra_msg_keys(original_model, resolved)
if self._supports_cache_control(original_model):
messages, tools = self._apply_cache_control(messages, tools)
max_tokens = max(1, max_tokens)
kwargs: dict[str, Any] = {
"model": resolved,
"messages": self._sanitize_messages(
self._sanitize_empty_content(messages), extra_keys=extra_msg_keys,
),
"max_tokens": max_tokens,
"temperature": temperature,
}
if self._gateway:
kwargs.update(self._gateway.litellm_kwargs)
self._apply_model_overrides(resolved, kwargs)
if self._langsmith_enabled:
kwargs.setdefault("callbacks", []).append("langsmith")
if self.api_key:
kwargs["api_key"] = self.api_key
if self.api_base:
kwargs["api_base"] = self.api_base
if self.extra_headers:
kwargs["extra_headers"] = self.extra_headers
if reasoning_effort:
kwargs["reasoning_effort"] = reasoning_effort
kwargs["drop_params"] = True
if tools:
kwargs["tools"] = tools
kwargs["tool_choice"] = tool_choice or "auto"
return kwargs, original_model
async def chat(
self,
messages: list[dict[str, Any]],
@@ -233,71 +292,54 @@ class LiteLLMProvider(LLMProvider):
reasoning_effort: str | None = None,
tool_choice: str | dict[str, Any] | None = None,
) -> LLMResponse:
"""
Send a chat completion request via LiteLLM.
Args:
messages: List of message dicts with 'role' and 'content'.
tools: Optional list of tool definitions in OpenAI format.
model: Model identifier (e.g., 'anthropic/claude-sonnet-4-5').
max_tokens: Maximum tokens in response.
temperature: Sampling temperature.
Returns:
LLMResponse with content and/or tool calls.
"""
original_model = model or self.default_model
model = self._resolve_model(original_model)
extra_msg_keys = self._extra_msg_keys(original_model, model)
if self._supports_cache_control(original_model):
messages, tools = self._apply_cache_control(messages, tools)
# Clamp max_tokens to at least 1 — negative or zero values cause
# LiteLLM to reject the request with "max_tokens must be at least 1".
max_tokens = max(1, max_tokens)
kwargs: dict[str, Any] = {
"model": model,
"messages": self._sanitize_messages(self._sanitize_empty_content(messages), extra_keys=extra_msg_keys),
"max_tokens": max_tokens,
"temperature": temperature,
}
if self._gateway:
kwargs.update(self._gateway.litellm_kwargs)
# Apply model-specific overrides (e.g. kimi-k2.5 temperature)
self._apply_model_overrides(model, kwargs)
if self._langsmith_enabled:
kwargs.setdefault("callbacks", []).append("langsmith")
# Pass api_key directly — more reliable than env vars alone
if self.api_key:
kwargs["api_key"] = self.api_key
# Pass api_base for custom endpoints
if self.api_base:
kwargs["api_base"] = self.api_base
# Pass extra headers (e.g. APP-Code for AiHubMix)
if self.extra_headers:
kwargs["extra_headers"] = self.extra_headers
if reasoning_effort:
kwargs["reasoning_effort"] = reasoning_effort
kwargs["drop_params"] = True
if tools:
kwargs["tools"] = tools
kwargs["tool_choice"] = tool_choice or "auto"
"""Send a chat completion request via LiteLLM."""
kwargs, _ = self._build_chat_kwargs(
messages, tools, model, max_tokens, temperature,
reasoning_effort, tool_choice,
)
try:
response = await acompletion(**kwargs)
return self._parse_response(response)
except Exception as e:
# Return error as content for graceful handling
return LLMResponse(
content=f"Error calling LLM: {str(e)}",
finish_reason="error",
)
async def chat_stream(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None = None,
model: str | None = None,
max_tokens: int = 4096,
temperature: float = 0.7,
reasoning_effort: str | None = None,
tool_choice: str | dict[str, Any] | None = None,
on_content_delta: Callable[[str], Awaitable[None]] | None = None,
) -> LLMResponse:
"""Stream a chat completion via LiteLLM, forwarding text deltas."""
kwargs, _ = self._build_chat_kwargs(
messages, tools, model, max_tokens, temperature,
reasoning_effort, tool_choice,
)
kwargs["stream"] = True
try:
stream = await acompletion(**kwargs)
chunks: list[Any] = []
async for chunk in stream:
chunks.append(chunk)
if on_content_delta:
delta = chunk.choices[0].delta if chunk.choices else None
text = getattr(delta, "content", None) if delta else None
if text:
await on_content_delta(text)
full_response = litellm.stream_chunk_builder(
chunks, messages=kwargs["messages"],
)
return self._parse_response(full_response)
except Exception as e:
return LLMResponse(
content=f"Error calling LLM: {str(e)}",
finish_reason="error",