Files
SneakyCode/app/agent/loop.py
Phillip Tarrant 273da21ef6 Fix doubled workspace path when LLM passes absolute-style relative paths
resolve_safe_path now detects when the LLM passes the workspace root as
a relative path (e.g. "home/user/project/file.py") and strips the prefix
before joining. Also updated the system prompt to explicitly instruct the
model to use relative paths for all tool arguments.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-11 08:47:57 -05:00

234 lines
8.9 KiB
Python

"""AgentLoop — ReAct-style tool-call loop for autonomous task execution."""
import json
from typing import Any
from app.agent.context import SessionContext
from app.models.config import AppConfig
from app.models.message import Message
from app.models.tool_call import ToolCall, ToolResult, ToolResultStatus
from app.services.llm import LLMClient, LLMConnectionError, LLMError
from app.services.permissions import PermissionsService
from app.services.streaming import StreamHandler
from app.tools.registry import ToolRegistry
from app.utils.display import (
print_error,
print_iteration_header,
print_tool_call,
print_tool_result,
print_token_usage,
print_warning,
)
from app.utils.logging import get_logger
logger = get_logger(__name__)
class AgentLoop:
"""ReAct-style agent loop that streams LLM responses and executes tool calls.
The loop sends conversation history to the LLM, parses tool calls from the
response, executes them with permission checks, feeds results back, and
repeats until the LLM produces a plain-text response or calls ``finish``.
"""
def __init__(
self,
config: AppConfig,
ctx: SessionContext,
client: LLMClient,
handler: StreamHandler,
registry: ToolRegistry,
permissions: PermissionsService,
) -> None:
self._config = config
self._ctx = ctx
self._client = client
self._handler = handler
self._registry = registry
self._permissions = permissions
self._tools_schema = registry.get_openai_tools_schema()
self._system_prompt = self._build_system_prompt()
def _build_system_prompt(self) -> str:
"""Build the system prompt including tool schemas and agent instructions."""
tool_names = [t["function"]["name"] for t in self._tools_schema]
return (
"You are SneakyCode, a local AI coding agent. "
"You help users with software engineering tasks by reading files, "
"searching code, and answering questions about their project.\n\n"
f"Workspace root: {self._config.agent.workspace_root}\n"
"IMPORTANT: All tool path arguments must be RELATIVE to the workspace root. "
'Use "." for the root, "app/main.py" for files, "app/" for subdirectories. '
"Never pass absolute paths or the workspace root path itself.\n\n"
"Available tools: " + ", ".join(tool_names) + "\n\n"
"When you have fully completed the user's request, call the `finish` tool "
"with a brief summary. If you can answer directly without tools, just respond "
"with text (no tool call needed)."
)
def _get_messages_with_system_prompt(self) -> list[Message]:
"""Prepend the system prompt to conversation history."""
system_msg = Message(role="system", content=self._system_prompt)
return [system_msg] + self._ctx.get_history()
async def run_turn(self, user_input: str) -> None:
"""Execute one full agent turn: add user message, loop until done.
Args:
user_input: The user's message text.
"""
self._ctx.add_message("user", user_input)
max_iter = self._config.agent.max_iterations
for iteration in range(1, max_iter + 1):
# Check token budget
if self._ctx.token_counter.is_over_budget():
print_warning("Token budget exceeded. Stopping agent loop.")
break
if iteration > 1:
print_iteration_header(iteration, max_iter)
# Stream LLM response
assistant_msg = await self._llm_step()
if assistant_msg is None:
break
# Record assistant message
self._ctx.add_message(
"assistant",
assistant_msg.content,
tool_calls=assistant_msg.tool_calls,
)
# Record token usage
if self._handler.usage:
self._ctx.token_counter.count_usage(self._handler.usage)
if self._config.display.show_token_usage:
total = self._ctx.token_counter.cumulative_usage.total_tokens
if total == 0:
total = self._ctx.estimated_tokens
print_token_usage(total, self._ctx.token_counter.budget)
self._handler.reset()
# No tool calls → task complete (plain text response)
if not assistant_msg.tool_calls:
break
# Execute tool calls
results = self._execute_tool_calls(assistant_msg.tool_calls)
# Add tool results to context
for result in results:
content = result.output if result.status == ToolResultStatus.SUCCESS else (result.error or "Unknown error")
self._ctx.add_message(
"tool",
content,
tool_call_id=result.tool_call_id,
name=result.tool_name,
)
# Check if finish tool was called
if any(r.tool_name == "finish" for r in results):
break
else:
print_warning(f"Agent reached maximum iterations ({max_iter}). Stopping.")
async def _llm_step(self) -> Message | None:
"""Stream one LLM response and return the accumulated Message.
Returns:
The assistant Message, or None if an error occurred.
"""
messages = self._get_messages_with_system_prompt()
try:
chunk_iter = self._client.stream_chat(messages, tools=self._tools_schema)
return await self._handler.process_stream(chunk_iter)
except KeyboardInterrupt:
print_warning("Response interrupted.")
self._handler.reset()
return None
except LLMConnectionError as e:
print_error(f"Connection error: {e}")
return None
except LLMError as e:
print_error(f"LLM error: {e}")
return None
def _execute_tool_calls(self, tool_calls: list[ToolCall]) -> list[ToolResult]:
"""Execute a list of tool calls with permission checks.
Args:
tool_calls: Tool calls from the LLM response.
Returns:
List of ToolResult objects (one per tool call).
"""
results: list[ToolResult] = []
available_names = list(self._registry.get_all().keys())
for tc in tool_calls:
name = tc.function.name
tc_id = tc.id
# Display the tool call
if self._config.display.show_tool_calls:
print_tool_call(name, tc.function.arguments)
# Parse arguments
try:
parsed_args: dict[str, Any] = json.loads(tc.function.arguments) if tc.function.arguments else {}
except json.JSONDecodeError as e:
result = ToolResult(
tool_call_id=tc_id,
tool_name=name,
status=ToolResultStatus.ERROR,
error=f"Invalid JSON in arguments: {e}",
)
results.append(result)
if self._config.display.show_tool_calls:
print_tool_result(name, result.error or "", is_error=True)
continue
# Look up tool
tool = self._registry.get(name)
if tool is None:
result = ToolResult(
tool_call_id=tc_id,
tool_name=name,
status=ToolResultStatus.ERROR,
error=f"Unknown tool '{name}'. Available: {available_names}",
)
results.append(result)
if self._config.display.show_tool_calls:
print_tool_result(name, result.error or "", is_error=True)
continue
# Check permissions (truncate args for display in prompt)
desc = tc.function.arguments[:120] + "..." if len(tc.function.arguments) > 120 else tc.function.arguments
if not self._permissions.check(name, description=desc):
result = ToolResult(
tool_call_id=tc_id,
tool_name=name,
status=ToolResultStatus.ERROR,
error=f"Permission denied for tool '{name}'",
)
results.append(result)
if self._config.display.show_tool_calls:
print_tool_result(name, result.error or "", is_error=True)
continue
# Execute tool (BaseTool.run never raises)
result = tool.run(tc_id, parsed_args)
results.append(result)
if self._config.display.show_tool_calls:
is_error = result.status == ToolResultStatus.ERROR
output = result.error if is_error else result.output
print_tool_result(name, output or "", is_error=is_error)
return results