Files
strix/strix/llm/llm.py
T
0xallam 56526cbf90 fix(agent): fix agent loop hanging and simplify LLM module
- Fix agent loop getting stuck by adding hard stop mechanism
- Add _force_stop flag for immediate task cancellation across threads
- Use thread-safe loop.call_soon_threadsafe for cross-thread cancellation
- Remove request_queue.py (eliminated threading/queue complexity causing hangs)
- Simplify llm.py: direct acompletion calls, cleaner streaming
- Reduce retry wait times to prevent long hangs during retries
- Make timeouts configurable (llm_max_retries, memory_compressor_timeout, sandbox_execution_timeout)
- Keep essential token tracking (input/output/cached tokens, cost, requests)
- Maintain Anthropic prompt caching for system messages
2026-01-14 18:54:45 -08:00

317 lines
11 KiB
Python

import asyncio
from collections.abc import AsyncIterator
from dataclasses import dataclass
from typing import Any
import litellm
from jinja2 import Environment, FileSystemLoader, select_autoescape
from litellm import acompletion, completion_cost, stream_chunk_builder, supports_reasoning
from litellm.utils import supports_prompt_caching, supports_vision
from strix.config import Config
from strix.llm.config import LLMConfig
from strix.llm.memory_compressor import MemoryCompressor
from strix.llm.utils import (
_truncate_to_first_function,
fix_incomplete_tool_call,
parse_tool_invocations,
)
from strix.skills import load_skills
from strix.tools import get_tools_prompt
from strix.utils.resource_paths import get_strix_resource_path
litellm.drop_params = True
litellm.modify_params = True
class LLMRequestFailedError(Exception):
def __init__(self, message: str, details: str | None = None):
super().__init__(message)
self.message = message
self.details = details
@dataclass
class LLMResponse:
content: str
tool_invocations: list[dict[str, Any]] | None = None
thinking_blocks: list[dict[str, Any]] | None = None
@dataclass
class RequestStats:
input_tokens: int = 0
output_tokens: int = 0
cached_tokens: int = 0
cost: float = 0.0
requests: int = 0
def to_dict(self) -> dict[str, int | float]:
return {
"input_tokens": self.input_tokens,
"output_tokens": self.output_tokens,
"cached_tokens": self.cached_tokens,
"cost": round(self.cost, 4),
"requests": self.requests,
}
class LLM:
def __init__(self, config: LLMConfig, agent_name: str | None = None):
self.config = config
self.agent_name = agent_name
self.agent_id: str | None = None
self._total_stats = RequestStats()
self.memory_compressor = MemoryCompressor(model_name=config.model_name)
self.system_prompt = self._load_system_prompt(agent_name)
reasoning = Config.get("strix_reasoning_effort")
if reasoning:
self._reasoning_effort = reasoning
elif config.scan_mode == "quick":
self._reasoning_effort = "medium"
else:
self._reasoning_effort = "high"
def _load_system_prompt(self, agent_name: str | None) -> str:
if not agent_name:
return ""
try:
prompt_dir = get_strix_resource_path("agents", agent_name)
skills_dir = get_strix_resource_path("skills")
env = Environment(
loader=FileSystemLoader([prompt_dir, skills_dir]),
autoescape=select_autoescape(enabled_extensions=(), default_for_string=False),
)
skills_to_load = [
*list(self.config.skills or []),
f"scan_modes/{self.config.scan_mode}",
]
skill_content = load_skills(skills_to_load, env)
env.globals["get_skill"] = lambda name: skill_content.get(name, "")
result = env.get_template("system_prompt.jinja").render(
get_tools_prompt=get_tools_prompt,
loaded_skill_names=list(skill_content.keys()),
**skill_content,
)
return str(result)
except Exception: # noqa: BLE001
return ""
def set_agent_identity(self, agent_name: str | None, agent_id: str | None) -> None:
if agent_name:
self.agent_name = agent_name
if agent_id:
self.agent_id = agent_id
async def generate(
self, conversation_history: list[dict[str, Any]]
) -> AsyncIterator[LLMResponse]:
messages = self._prepare_messages(conversation_history)
max_retries = int(Config.get("strix_llm_max_retries") or "5")
for attempt in range(max_retries + 1):
try:
async for response in self._stream(messages):
yield response
return # noqa: TRY300
except Exception as e: # noqa: BLE001
if attempt >= max_retries or not self._should_retry(e):
self._raise_error(e)
wait = min(10, 2 * (2**attempt))
await asyncio.sleep(wait)
async def _stream(self, messages: list[dict[str, Any]]) -> AsyncIterator[LLMResponse]:
accumulated = ""
chunks: list[Any] = []
self._total_stats.requests += 1
response = await acompletion(**self._build_completion_args(messages), stream=True)
async for chunk in response:
chunks.append(chunk)
delta = self._get_chunk_content(chunk)
if delta:
accumulated += delta
if "</function>" in accumulated:
accumulated = accumulated[
: accumulated.find("</function>") + len("</function>")
]
yield LLMResponse(content=accumulated)
if chunks:
self._update_usage_stats(stream_chunk_builder(chunks))
accumulated = fix_incomplete_tool_call(_truncate_to_first_function(accumulated))
yield LLMResponse(
content=accumulated,
tool_invocations=parse_tool_invocations(accumulated),
thinking_blocks=self._extract_thinking(chunks),
)
def _prepare_messages(self, conversation_history: list[dict[str, Any]]) -> list[dict[str, Any]]:
messages = [{"role": "system", "content": self.system_prompt}]
if self.agent_name:
messages.append(
{
"role": "user",
"content": (
f"\n\n<agent_identity>\n"
f"<meta>Internal metadata: do not echo or reference.</meta>\n"
f"<agent_name>{self.agent_name}</agent_name>\n"
f"<agent_id>{self.agent_id}</agent_id>\n"
f"</agent_identity>\n\n"
),
}
)
compressed = list(self.memory_compressor.compress_history(conversation_history))
conversation_history.clear()
conversation_history.extend(compressed)
messages.extend(compressed)
if self._is_anthropic() and self.config.enable_prompt_caching:
messages = self._add_cache_control(messages)
return messages
def _build_completion_args(self, messages: list[dict[str, Any]]) -> dict[str, Any]:
if not self._supports_vision():
messages = self._strip_images(messages)
args: dict[str, Any] = {
"model": self.config.model_name,
"messages": messages,
"timeout": self.config.timeout,
"stream_options": {"include_usage": True},
"stop": ["</function>"],
}
if api_key := Config.get("llm_api_key"):
args["api_key"] = api_key
if api_base := (
Config.get("llm_api_base")
or Config.get("openai_api_base")
or Config.get("litellm_base_url")
):
args["api_base"] = api_base
if self._supports_reasoning():
args["reasoning_effort"] = self._reasoning_effort
return args
def _get_chunk_content(self, chunk: Any) -> str:
if chunk.choices and hasattr(chunk.choices[0], "delta"):
return getattr(chunk.choices[0].delta, "content", "") or ""
return ""
def _extract_thinking(self, chunks: list[Any]) -> list[dict[str, Any]] | None:
if not chunks or not self._supports_reasoning():
return None
try:
resp = stream_chunk_builder(chunks)
if resp.choices and hasattr(resp.choices[0].message, "thinking_blocks"):
blocks: list[dict[str, Any]] = resp.choices[0].message.thinking_blocks
return blocks
except Exception: # noqa: BLE001, S110 # nosec B110
pass
return None
def _update_usage_stats(self, response: Any) -> None:
try:
if hasattr(response, "usage") and response.usage:
input_tokens = getattr(response.usage, "prompt_tokens", 0)
output_tokens = getattr(response.usage, "completion_tokens", 0)
cached_tokens = 0
if hasattr(response.usage, "prompt_tokens_details"):
prompt_details = response.usage.prompt_tokens_details
if hasattr(prompt_details, "cached_tokens"):
cached_tokens = prompt_details.cached_tokens or 0
else:
input_tokens = 0
output_tokens = 0
cached_tokens = 0
try:
cost = completion_cost(response) or 0.0
except Exception: # noqa: BLE001
cost = 0.0
self._total_stats.input_tokens += input_tokens
self._total_stats.output_tokens += output_tokens
self._total_stats.cached_tokens += cached_tokens
self._total_stats.cost += cost
except Exception: # noqa: BLE001, S110 # nosec B110
pass
def _should_retry(self, e: Exception) -> bool:
code = getattr(e, "status_code", None) or getattr(
getattr(e, "response", None), "status_code", None
)
return code is None or litellm._should_retry(code)
def _raise_error(self, e: Exception) -> None:
from strix.telemetry import posthog
posthog.error("llm_error", type(e).__name__)
raise LLMRequestFailedError(f"LLM request failed: {type(e).__name__}", str(e)) from e
def _is_anthropic(self) -> bool:
if not self.config.model_name:
return False
return any(p in self.config.model_name.lower() for p in ["anthropic/", "claude"])
def _supports_vision(self) -> bool:
try:
return bool(supports_vision(model=self.config.model_name))
except Exception: # noqa: BLE001
return False
def _supports_reasoning(self) -> bool:
try:
return bool(supports_reasoning(model=self.config.model_name))
except Exception: # noqa: BLE001
return False
def _strip_images(self, messages: list[dict[str, Any]]) -> list[dict[str, Any]]:
result = []
for msg in messages:
content = msg.get("content")
if isinstance(content, list):
text_parts = []
for item in content:
if isinstance(item, dict) and item.get("type") == "text":
text_parts.append(item.get("text", ""))
elif isinstance(item, dict) and item.get("type") == "image_url":
text_parts.append("[Image removed - model doesn't support vision]")
result.append({**msg, "content": "\n".join(text_parts)})
else:
result.append(msg)
return result
def _add_cache_control(self, messages: list[dict[str, Any]]) -> list[dict[str, Any]]:
if not messages or not supports_prompt_caching(self.config.model_name):
return messages
result = list(messages)
if result[0].get("role") == "system":
content = result[0]["content"]
result[0] = {
**result[0],
"content": [
{"type": "text", "text": content, "cache_control": {"type": "ephemeral"}}
]
if isinstance(content, str)
else content,
}
return result