nanobot/nanobot/utils/runtime.py

89 lines
3.0 KiB
Python

"""Runtime-specific helper functions and constants."""
from __future__ import annotations
from typing import Any
from loguru import logger
from nanobot.utils.helpers import stringify_text_blocks
_MAX_REPEAT_EXTERNAL_LOOKUPS = 2
EMPTY_FINAL_RESPONSE_MESSAGE = (
"I completed the tool steps but couldn't produce a final answer. "
"Please try again or narrow the task."
)
FINALIZATION_RETRY_PROMPT = (
"You have already finished the tool work. Do not call any more tools. "
"Using only the conversation and tool results above, provide the final answer for the user now."
)
def empty_tool_result_message(tool_name: str) -> str:
"""Short prompt-safe marker for tools that completed without visible output."""
return f"({tool_name} completed with no output)"
def ensure_nonempty_tool_result(tool_name: str, content: Any) -> Any:
"""Replace semantically empty tool results with a short marker string."""
if content is None:
return empty_tool_result_message(tool_name)
if isinstance(content, str) and not content.strip():
return empty_tool_result_message(tool_name)
if isinstance(content, list):
if not content:
return empty_tool_result_message(tool_name)
text_payload = stringify_text_blocks(content)
if text_payload is not None and not text_payload.strip():
return empty_tool_result_message(tool_name)
return content
def is_blank_text(content: str | None) -> bool:
"""True when *content* is missing or only whitespace."""
return content is None or not content.strip()
def build_finalization_retry_message() -> dict[str, str]:
"""A short no-tools-allowed prompt for final answer recovery."""
return {"role": "user", "content": FINALIZATION_RETRY_PROMPT}
def external_lookup_signature(tool_name: str, arguments: dict[str, Any]) -> str | None:
"""Stable signature for repeated external lookups we want to throttle."""
if tool_name == "web_fetch":
url = str(arguments.get("url") or "").strip()
if url:
return f"web_fetch:{url.lower()}"
if tool_name == "web_search":
query = str(arguments.get("query") or arguments.get("search_term") or "").strip()
if query:
return f"web_search:{query.lower()}"
return None
def repeated_external_lookup_error(
tool_name: str,
arguments: dict[str, Any],
seen_counts: dict[str, int],
) -> str | None:
"""Block repeated external lookups after a small retry budget."""
signature = external_lookup_signature(tool_name, arguments)
if signature is None:
return None
count = seen_counts.get(signature, 0) + 1
seen_counts[signature] = count
if count <= _MAX_REPEAT_EXTERNAL_LOOKUPS:
return None
logger.warning(
"Blocking repeated external lookup {} on attempt {}",
signature[:160],
count,
)
return (
"Error: repeated external lookup blocked. "
"Use the results you already have to answer, or try a meaningfully different source."
)