Files
nanobot/nanobot/agent/progress_hook.py
T

223 lines
8.2 KiB
Python

"""Agent hook that adapts runner events into channel progress UI."""
from __future__ import annotations
import inspect
import json
from typing import Any, Awaitable, Callable, cast
from loguru import logger
from nanobot.agent.hook import AgentHook, AgentHookContext
from nanobot.providers.base import ToolCallRequest
from nanobot.utils.helpers import IncrementalThinkExtractor, strip_think
from nanobot.utils.progress_events import (
build_tool_event_finish_payloads,
build_tool_event_start_payload,
invoke_on_progress,
on_progress_accepts_tool_events,
)
from nanobot.utils.tool_hints import format_tool_hints
class AgentProgressHook(AgentHook):
"""Translate runner lifecycle events into user-visible progress signals."""
def __init__(
self,
on_progress: Callable[..., Awaitable[None]] | None = None,
on_stream: Callable[[str], Awaitable[None]] | None = None,
on_stream_end: Callable[..., Awaitable[None]] | None = None,
*,
session_key: str | None = None,
tool_hint_max_length: int = 40,
on_iteration: Callable[[int], None] | None = None,
) -> None:
super().__init__(reraise=True)
self._on_progress = on_progress
self._on_stream = on_stream
self._on_stream_end = on_stream_end
self._session_key = session_key
self._tool_hint_max_length = tool_hint_max_length
self._on_iteration = on_iteration
self._stream_buf = ""
self._think_extractor = IncrementalThinkExtractor()
self._reasoning_open = False
def wants_streaming(self) -> bool:
return self._on_stream is not None
@staticmethod
def _strip_think(text: str | None) -> str | None:
if not text:
return None
return strip_think(text) or None
def _tool_hint(self, tool_calls: list[Any]) -> str:
return format_tool_hints(tool_calls, max_length=self._tool_hint_max_length)
@staticmethod
def _on_progress_accepts(cb: Callable[..., Any], name: str) -> bool:
try:
sig = inspect.signature(cb)
except (TypeError, ValueError):
return False
if any(p.kind == inspect.Parameter.VAR_KEYWORD for p in sig.parameters.values()):
return True
return name in sig.parameters
async def on_stream(self, context: AgentHookContext, delta: str) -> None:
prev_clean = strip_think(self._stream_buf)
self._stream_buf += delta
new_clean = strip_think(self._stream_buf)
incremental = new_clean[len(prev_clean) :]
if await self._think_extractor.feed(self._stream_buf, self.emit_reasoning):
context.streamed_reasoning = True
if incremental:
# Answer text has started; close the reasoning segment so the UI can
# lock the bubble before the answer renders below it.
await self.emit_reasoning_end()
if self._on_stream:
await self._on_stream(incremental)
async def on_stream_end(self, context: AgentHookContext, *, resuming: bool) -> None:
await self.emit_reasoning_end()
if self._on_stream_end:
kwargs: dict[str, bool] = {"resuming": resuming}
if (
context.stream_continues_current_message
and self._on_progress_accepts(self._on_stream_end, "merge_next")
):
kwargs["merge_next"] = True
await self._on_stream_end(**kwargs)
self._stream_buf = ""
self._think_extractor.reset()
async def before_iteration(self, context: AgentHookContext) -> None:
if self._on_iteration:
self._on_iteration(context.iteration)
logger.debug(
"Starting agent loop iteration {} for session {}",
context.iteration,
self._session_key,
)
async def on_provider_tool_event(
self,
context: AgentHookContext,
event: dict[str, Any],
) -> None:
if not self._on_progress:
return
phase = event.get("phase")
name = event.get("name")
call_id = event.get("call_id")
if (
phase not in {"start", "end", "error"}
or not isinstance(name, str)
or not name
or not call_id
):
return
arguments = event.get("arguments")
if not isinstance(arguments, dict):
arguments = {}
payload: dict[str, Any] = {
"version": 1,
"phase": phase,
"call_id": str(call_id),
"name": name,
"arguments": arguments,
"result": event.get("result") if phase == "end" else None,
"error": event.get("error") if phase == "error" else None,
"files": [],
"embeds": [],
}
if phase == "start":
await self.emit_reasoning_end()
tool_call = ToolCallRequest(id=str(call_id), name=name, arguments=arguments)
tool_hint = self._strip_think(self._tool_hint([tool_call])) or name
await invoke_on_progress(
self._on_progress,
tool_hint,
tool_hint=True,
tool_events=[payload],
)
logger.info(
"Provider-hosted tool call: {}({})",
name,
json.dumps(arguments, ensure_ascii=False)[:200],
)
return
if on_progress_accepts_tool_events(self._on_progress):
await invoke_on_progress(
self._on_progress,
"",
tool_hint=False,
tool_events=[payload],
)
async def before_execute_tools(self, context: AgentHookContext) -> None:
if self._on_progress:
if not self._on_stream and not context.streamed_content:
thought = self._strip_think(context.response.content if context.response else None)
if thought:
await self._on_progress(thought)
tool_hint = self._strip_think(self._tool_hint(context.tool_calls))
tool_events = [build_tool_event_start_payload(tc) for tc in context.tool_calls]
await invoke_on_progress(
self._on_progress,
cast(str, tool_hint),
tool_hint=True,
tool_events=tool_events,
)
for tc in context.tool_calls:
args_str = json.dumps(tc.arguments, ensure_ascii=False)
logger.info("Tool call: {}({})", tc.name, args_str[:200])
async def emit_reasoning(self, reasoning_content: str | None) -> None:
"""Publish a reasoning chunk; channel plugins decide whether to render."""
if (
self._on_progress
and reasoning_content
and self._on_progress_accepts(self._on_progress, "reasoning")
):
self._reasoning_open = True
await self._on_progress(reasoning_content, reasoning=True)
async def emit_reasoning_end(self) -> None:
"""Close the current reasoning stream segment, if any was open."""
if self._reasoning_open and self._on_progress:
self._reasoning_open = False
await self._on_progress("", reasoning_end=True)
else:
self._reasoning_open = False
async def after_iteration(self, context: AgentHookContext) -> None:
if (
self._on_progress
and context.tool_calls
and context.tool_events
and on_progress_accepts_tool_events(self._on_progress)
):
tool_events = build_tool_event_finish_payloads(context)
if tool_events:
await invoke_on_progress(
self._on_progress,
"",
tool_hint=False,
tool_events=tool_events,
)
u = context.usage or {}
logger.debug(
"LLM usage: prompt={} completion={} cached={}",
u.get("prompt_tokens", 0),
u.get("completion_tokens", 0),
u.get("cached_tokens", 0),
)
def finalize_content(self, context: AgentHookContext, content: str | None) -> str | None:
return self._strip_think(content)