Files
wehub-resource-sync e4dcfc49aa
Tests / Import Check (Python 3.13) (push) Has been cancelled
Tests / Import Check (Python 3.14) (push) Has been cancelled
Tests / Python Tests (Python 3.11) (push) Has been cancelled
Tests / Python Tests (Python 3.12) (push) Has been cancelled
Tests / Python Tests (Python 3.14) (push) Has been cancelled
Tests / Test Summary (push) Has been cancelled
Tests / Lint and Format (push) Has been cancelled
Tests / Web Node Tests (push) Has been cancelled
Tests / Import Check (Python 3.11) (push) Has been cancelled
Tests / Import Check (Python 3.12) (push) Has been cancelled
Tests / Python Tests (Python 3.13) (push) Has been cancelled
chore: import upstream snapshot with attribution
2026-07-13 13:00:43 +08:00

756 lines
28 KiB
Python

"""Single-loop chat agent.
One chat turn = ONE agent loop over a single growing conversation:
* each round is one LLM call; its text streams to the user as a ``content``
block, and its tool calls are dispatched with their ``role=tool`` results
appended back into the conversation;
* a round that DOES call tools is "narration" — its text is a preamble to
the tool work — and the loop continues;
* a round that calls NO tools is the ``finish``: its text IS the final
user-facing answer and the loop ends (the model deciding it is done; a
first round without tool calls is the "no exploration needed" fast path);
* if the round budget runs out while tools are still being requested, one
final tool-less ``finish`` round is forced.
``ask_user`` pauses the turn for a reply and resumes in-protocol; an
unresolved pause (or a terminator tool) halts the turn.
There is no separate respond pass and no text destination has to be guessed
mid-stream: every round's text streams to the user as it is generated, and a
``call_role`` (``narration`` vs ``finish``) emitted when the round completes
tells the frontend how to render that round's text.
"""
from __future__ import annotations
from contextlib import suppress
from dataclasses import dataclass, field
import logging
import re
from typing import TYPE_CHECKING, Any
from deeptutor.agents._shared.capability_result import emit_capability_result
from deeptutor.core.agentic.tool_dispatch import DispatchOutcome
from deeptutor.core.context import UnifiedContext
from deeptutor.core.stream_bus import StreamBus
from deeptutor.core.trace import build_trace_metadata, merge_trace_metadata, new_call_id
from deeptutor.services.llm import clean_thinking_tags
from deeptutor.services.llm.multimodal import should_degrade_to_text, strip_image_parts_inplace
if TYPE_CHECKING: # pragma: no cover
from deeptutor.agents.chat.agentic_pipeline import AgenticChatPipeline
logger = logging.getLogger(__name__)
# The loop runs over a single conversation; this is the maximum number of
# tool-calling rounds before a tool-less finish is forced. The model normally
# exits earlier by replying without tool calls.
LOOP_STAGE = "responding"
_THINK_OPEN_RE = re.compile(r"<\s*think(?:ing)?\b[^>]*>", re.IGNORECASE)
_THINK_CLOSE_RE = re.compile(r"<\s*/\s*think(?:ing)?\s*>", re.IGNORECASE)
# Longest partial tag worth waiting a chunk for (e.g. "</thinking" + slack).
_TAG_HOLDBACK_CHARS = 24
class InlineThinkFilter:
"""Incremental ``<think>``/``<thinking>`` splitter for streamed content.
Some providers surface reasoning inline in the *content* channel (instead
of ``reasoning_content``), wrapped in think tags. Splitting at streaming
time keeps the user-facing content channel clean everywhere downstream —
the live bubble, the persisted message, and the loop's finish detection —
in one place. The raw text (tags included) still goes back into the LLM
conversation untouched.
"""
def __init__(self) -> None:
self._buffer = ""
self._in_think = False
def feed(self, chunk: str) -> list[tuple[str, str]]:
"""Consume *chunk*; return ``(kind, text)`` segments, kind in
``{"content", "thinking"}``. May hold back a partial trailing tag
until the next chunk (``flush`` releases it at stream end)."""
self._buffer += chunk
segments: list[tuple[str, str]] = []
while True:
pattern = _THINK_CLOSE_RE if self._in_think else _THINK_OPEN_RE
match = pattern.search(self._buffer)
if match is None:
break
if match.start() > 0:
segments.append((self._kind(), self._buffer[: match.start()]))
self._buffer = self._buffer[match.end() :]
self._in_think = not self._in_think
emit_upto = len(self._buffer)
tag_start = self._buffer.rfind("<")
if (
tag_start != -1
and len(self._buffer) - tag_start <= _TAG_HOLDBACK_CHARS
and ">" not in self._buffer[tag_start:]
):
emit_upto = tag_start
if emit_upto > 0:
segments.append((self._kind(), self._buffer[:emit_upto]))
self._buffer = self._buffer[emit_upto:]
return segments
def flush(self) -> list[tuple[str, str]]:
"""Release whatever is still buffered (stream ended)."""
if not self._buffer:
return []
segments = [(self._kind(), self._buffer)]
self._buffer = ""
return segments
def _kind(self) -> str:
return "thinking" if self._in_think else "content"
@dataclass(slots=True)
class AgentLoopState:
"""Turn-level counters shared across the loop's rounds."""
rounds: int = 0
tool_steps: int = 0
sources: list[dict[str, Any]] = field(default_factory=list)
@dataclass(slots=True)
class LLMCallResult:
text: str
tool_calls: list[dict[str, Any]] = field(default_factory=list)
finish_reason: str = ""
@dataclass(slots=True)
class LoopOutcome:
"""Result of running the turn's loop.
``final_text`` is the user-facing answer (the finish round's text, or a
terminator tool's content). ``completed`` is False only when the turn
halted on an unresolved ``ask_user`` pause — the pending question is then
the turn's final artefact.
"""
final_text: str = ""
completed: bool = False
class AgentLoop:
"""Run one chat turn as a single agent loop over one conversation."""
def __init__(
self,
*,
pipeline: "AgenticChatPipeline",
context: UnifiedContext,
stream: StreamBus,
client: Any,
enabled_tools: list[str],
tool_schemas: list[dict[str, Any]] | None,
) -> None:
self.pipeline = pipeline
self.context = context
self.stream = stream
self.client = client
self.enabled_tools = enabled_tools
self.tool_schemas = tool_schemas
async def run(self) -> None:
state = AgentLoopState()
# Optional async pre-pass briefings (e.g. explore_context) run BEFORE
# the answer stage so they form their own preceding activity group and
# their grounding can ride in the loop's user-message seed.
capability_briefing = await self.pipeline._capability_pre_loop_briefings(
self.context, self.stream
)
async with self.stream.stage(LOOP_STAGE, source="chat"):
seed_block = await self.pipeline._retrieve_kb_seed_block(self.context, self.stream)
capability_seed = self.pipeline._capability_pre_loop_seed(self.context)
seed_block = "\n\n".join(
block
for block in (
seed_block.strip(),
capability_seed.strip(),
capability_briefing.strip(),
)
if block
)
messages = self.pipeline._build_loop_messages(
context=self.context,
enabled_tools=self.enabled_tools,
kb_seed=seed_block,
include_tool_manifest=bool(self.tool_schemas),
)
outcome = await self._run_loop(
messages=messages,
state=state,
checkpoint_boundary=len(messages),
)
if state.sources:
await self.stream.sources(
state.sources,
source="chat",
stage=LOOP_STAGE,
metadata={"trace_kind": "sources"},
)
await emit_capability_result(
self.stream,
{
"response": outcome.final_text,
"completed": outcome.completed,
"engine": "agent_loop",
"rounds": state.rounds,
"tool_steps": state.tool_steps,
},
source="chat",
usage=self.pipeline.usage,
)
def _clean(self, text: str) -> str:
return clean_thinking_tags(text, self.pipeline.binding, self.pipeline.model).strip()
# ---- agent loop --------------------------------------------------------
async def _run_loop(
self,
*,
messages: list[dict[str, Any]],
state: AgentLoopState,
checkpoint_boundary: int,
) -> LoopOutcome:
"""Run rounds of one LLM call + tool dispatch over *messages*.
A round with tool calls keeps its assistant message (text + tool
calls) and the ``role=tool`` results in-conversation, then continues.
A round with no tool calls is the finish: its text — already streamed
to the user — is the answer, and the loop ends.
"""
explore_label = self.pipeline._t("labels.exploring", default="Exploring")
nudged_empty_finish = False
for _round in range(max(1, self.pipeline.effective_max_rounds(self.context))):
try:
result = await self._call_llm(
messages=messages,
label=explore_label,
call_kind="agent_loop_round",
trace_role="explore",
max_tokens=self.pipeline.loop_max_tokens,
tool_schemas=self.tool_schemas,
)
except Exception as exc:
# A mid-loop LLM failure (timeout / transient network) must not
# discard a turn that already gathered useful work. Salvage it
# with a forced finish; only a failure on the very first round
# (nothing gathered yet) propagates as before.
if state.rounds == 0:
raise
logger.warning(
"agent loop round failed after %d round(s); forcing finish: %s",
state.rounds,
exc,
)
return await self._forced_finish(messages, state, reason="error")
state.rounds += 1
if not result.tool_calls:
final_text = self._clean(result.text)
if not final_text and not nudged_empty_finish:
# The round produced only internal reasoning (e.g. the
# whole reply inside <think>) — the model planned but
# never acted. Keep its raw text in-conversation (the
# plan/script lives there) and nudge it once to act
# instead of falling back to an empty answer.
nudged_empty_finish = True
await self.stream.progress(
self.pipeline._t(
"notices.empty_finish_nudged",
default=(
"The round produced only internal reasoning; "
"asked the model to continue."
),
),
source="chat",
stage=LOOP_STAGE,
metadata={"trace_kind": "warning"},
)
if result.text:
messages.append({"role": "assistant", "content": result.text})
messages.append(
{
"role": "user",
"content": self.pipeline._t(
"loop.finish_empty_nudge",
default=(
"Your previous round produced only internal "
"reasoning — no tool call and no user-facing "
"answer. Continue now: either call the tools "
"to execute your plan, or write the final "
"user-facing answer directly."
),
),
}
)
continue
# Finish: the text streamed live this round IS the answer.
return await self._finalize_finish(final_text)
messages.append(_assistant_message_with_tool_calls(result.text, result.tool_calls))
dispatch = await self.pipeline._dispatch_tool_calls(
tool_calls=result.tool_calls,
context=self.context,
stream=self.stream,
iteration_index=state.tool_steps,
stage=LOOP_STAGE,
)
state.tool_steps += 1
state.sources.extend(dispatch.sources)
messages.extend(dispatch.tool_messages)
if dispatch.pause:
resumed = await self.pipeline._await_user_reply_and_resolve(
context=self.context,
stream=self.stream,
dispatch=dispatch,
)
if not resumed:
# The pending question is already the turn's final
# artefact (or the user abandoned the turn) — stop.
return LoopOutcome(final_text="", completed=False)
# The user's answers were substituted into the matching
# ``role=tool`` message; the next round sees them in-protocol.
continue
checkpoint_boundary = self._fold_context_checkpoint(
messages=messages,
dispatch=dispatch,
checkpoint_boundary=checkpoint_boundary,
)
if dispatch.terminate:
payload = dispatch.terminate_payload or {}
await self.pipeline._emit_terminator_final_response(self.stream, payload)
return LoopOutcome(
final_text=str(payload.get("content") or ""),
completed=True,
)
# Round budget ran out while still requesting tools — force a finish.
return await self._forced_finish(messages, state)
def _fold_context_checkpoint(
self,
*,
messages: list[dict[str, Any]],
dispatch: DispatchOutcome,
checkpoint_boundary: int,
) -> int:
summary = _last_context_checkpoint_summary(dispatch)
if not summary:
return checkpoint_boundary
prefix = messages[:checkpoint_boundary]
prefix.append(
{
"role": "system",
"content": f"[Context checkpoint]\n{summary}",
}
)
messages[:] = prefix
return len(messages)
async def _forced_finish(
self,
messages: list[dict[str, Any]],
state: AgentLoopState,
*,
reason: str = "budget",
) -> LoopOutcome:
if reason == "error":
notice = self.pipeline._t(
"notices.loop_error_finish",
default="A step failed; answering with what has been gathered.",
)
else:
notice = self.pipeline._t(
"notices.loop_budget_exhausted",
default="Exploration budget reached; answering with what has been gathered.",
)
await self.stream.progress(
notice,
source="chat",
stage=LOOP_STAGE,
metadata={"trace_kind": "warning"},
)
messages.append({"role": "user", "content": self.pipeline._finish_exhausted_instruction()})
try:
result = await self._call_llm(
messages=messages,
label=self.pipeline._t("labels.final_response", default="Final response"),
call_kind="llm_final_response",
trace_role="response",
max_tokens=self.pipeline.loop_max_tokens,
tool_schemas=None, # tools disabled so the model must finish
)
except Exception as exc:
# The salvage call itself failed (e.g. the provider is still
# stalling). Don't bubble up and lose the turn — emit the graceful
# fallback answer instead.
logger.warning("forced-finish LLM call failed: %s", exc)
return await self._finalize_finish("")
state.rounds += 1
return await self._finalize_finish(result.text)
async def _finalize_finish(self, raw_text: str) -> LoopOutcome:
final_text = self._clean(raw_text)
if not final_text:
# The finish round produced no usable text; nothing streamed to
# the user, so emit a fallback answer here.
final_text = self.pipeline._t(
"notices.empty_final_response",
default=(
"I could not produce a useful response from the model "
"output. Please try again or narrow the request."
),
)
await self.pipeline._emit_protocol_fallback_final_response(self.stream, final_text)
return LoopOutcome(final_text=final_text, completed=True)
# ---- LLM call ----------------------------------------------------------
async def _call_llm(
self,
*,
messages: list[dict[str, Any]],
label: str,
call_kind: str,
trace_role: str,
max_tokens: int,
tool_schemas: list[dict[str, Any]] | None = None,
) -> LLMCallResult:
await self.pipeline._guard_context_window(messages, self.stream)
stage = LOOP_STAGE
call_id = new_call_id(f"chat-{stage}")
trace_meta = build_trace_metadata(
call_id=call_id,
phase=stage,
label=label,
call_kind=call_kind,
trace_id=call_id,
trace_role=trace_role,
trace_group="stage",
)
await self.stream.progress(
label,
source="chat",
stage=stage,
metadata=merge_trace_metadata(
trace_meta,
{"trace_kind": "call_status", "call_state": "running"},
),
)
kwargs: dict[str, Any] = {
"model": self.pipeline.model,
"messages": messages,
"stream": True,
**self.pipeline._completion_kwargs(max_tokens=max_tokens),
}
if self.pipeline.usage is not None:
kwargs["stream_options"] = {"include_usage": True}
if tool_schemas:
kwargs["tools"] = tool_schemas
kwargs["tool_choice"] = "auto"
before_usage_calls = self.pipeline.usage.calls
text_parts: list[str] = []
tool_acc: dict[int, dict[str, str]] = {}
output_chars = 0
finish_reason = ""
think_filter = InlineThinkFilter()
chunk_meta = merge_trace_metadata(trace_meta, {"trace_kind": "llm_chunk"})
async def _emit_segments(segments: list[tuple[str, str]]) -> None:
for kind, segment in segments:
if kind == "content":
await self.stream.content(
segment, source="chat", stage=stage, metadata=chunk_meta
)
else:
await self.stream.thinking(
segment, source="chat", stage=stage, metadata=chunk_meta
)
response_stream = await self._create_response_stream(kwargs, trace_meta, stage)
try:
async for chunk in response_stream:
usage = getattr(chunk, "usage", None)
if usage is not None:
self.pipeline.usage.add_from_response(usage)
choices = getattr(chunk, "choices", None) or []
if not choices:
continue
choice = choices[0]
if getattr(choice, "finish_reason", None):
finish_reason = str(choice.finish_reason)
delta = getattr(choice, "delta", None)
if delta is None:
continue
reasoning_text = getattr(delta, "reasoning_content", None) or getattr(
delta,
"reasoning",
None,
)
if reasoning_text:
output_chars += len(reasoning_text)
await self.stream.thinking(
reasoning_text, source="chat", stage=stage, metadata=chunk_meta
)
content = getattr(delta, "content", None)
if content:
output_chars += len(content)
text_parts.append(content)
# Every round's text streams to the user; the round's
# call_role (emitted at completion) tells the frontend
# whether to render it as narration or as the answer.
# Inline <think> segments are split off to the thinking
# channel so the content stream stays user-facing.
await _emit_segments(think_filter.feed(content))
for tc_delta in getattr(delta, "tool_calls", None) or []:
index = int(getattr(tc_delta, "index", 0) or 0)
acc = tool_acc.setdefault(index, {"id": "", "name": "", "arguments": ""})
tcid = getattr(tc_delta, "id", None)
if tcid:
acc["id"] += str(tcid)
fn = getattr(tc_delta, "function", None)
if fn is None:
continue
name = getattr(fn, "name", None)
arguments = getattr(fn, "arguments", None)
if name:
acc["name"] += str(name)
output_chars += len(str(name))
if arguments:
acc["arguments"] += str(arguments)
output_chars += len(str(arguments))
finally:
close = getattr(response_stream, "close", None)
if callable(close):
with suppress(Exception):
await close()
await _emit_segments(think_filter.flush())
text = "".join(text_parts)
if self.pipeline.usage.calls == before_usage_calls:
self.pipeline.usage.add_estimated(
input_chars=sum(_message_content_chars(message) for message in messages),
output_chars=output_chars,
)
tool_calls = [
{
"id": data.get("id") or f"call_{idx}",
"name": data.get("name", ""),
"arguments": data.get("arguments") or "{}",
}
for idx, data in sorted(tool_acc.items())
if data.get("name")
]
await self.stream.progress(
"",
source="chat",
stage=stage,
metadata=merge_trace_metadata(
trace_meta,
{
"trace_kind": "call_status",
"call_state": "complete",
# A round with tool calls is narration; a tool-less round
# is the finish whose text is the user-facing answer.
"call_role": "narration" if tool_calls else "finish",
},
),
)
return LLMCallResult(text=text, tool_calls=tool_calls, finish_reason=finish_reason)
async def _create_response_stream(
self,
kwargs: dict[str, Any],
trace_meta: dict[str, Any],
stage: str,
) -> Any:
try:
return await self.client.chat.completions.create(**kwargs)
except Exception as exc:
if "stream_options" in kwargs and _is_stream_options_unsupported(exc):
retry_kwargs = dict(kwargs)
retry_kwargs.pop("stream_options", None)
return await self.client.chat.completions.create(**retry_kwargs)
if kwargs.get("tools") and _is_tool_schema_unsupported(exc):
await self.stream.progress(
self.pipeline._t(
"notices.tool_schema_fallback",
default="Provider rejected native tool schemas; retrying without tools.",
),
source="chat",
stage=stage,
metadata=merge_trace_metadata(
trace_meta,
{"trace_kind": "warning", "tool_schema_fallback": True},
),
)
retry_kwargs = dict(kwargs)
retry_kwargs.pop("tools", None)
retry_kwargs.pop("tool_choice", None)
self.tool_schemas = None
return await self.client.chat.completions.create(**retry_kwargs)
if _is_image_input_unsupported(exc) and should_degrade_to_text(
self.pipeline.binding,
self.pipeline.model,
kwargs.get("messages") or [],
):
strip_image_parts_inplace(kwargs["messages"])
await self.stream.progress(
self.pipeline._t(
"notices.image_fallback",
default="Model does not support image input; retrying without images.",
),
source="chat",
stage=stage,
metadata=merge_trace_metadata(
trace_meta,
{"trace_kind": "warning", "image_fallback": True},
),
)
return await self.client.chat.completions.create(**kwargs)
raise
def _assistant_message_with_tool_calls(
content: str,
tool_calls: list[dict[str, Any]],
) -> dict[str, Any]:
return {
"role": "assistant",
"content": content or None,
"tool_calls": [
{
"id": tc["id"],
"type": "function",
"function": {
"name": tc["name"],
"arguments": tc.get("arguments") or "{}",
},
}
for tc in tool_calls
],
}
def _message_content_chars(message: dict[str, Any]) -> int:
content = message.get("content")
if isinstance(content, str):
return len(content)
if isinstance(content, list):
total = 0
for part in content:
if isinstance(part, dict):
total += len(str(part.get("text") or ""))
elif isinstance(part, str):
total += len(part)
return total
return 0
def _last_context_checkpoint_summary(dispatch: DispatchOutcome) -> str:
summary = ""
for tool_message in dispatch.tool_messages:
tool_call_id = str(tool_message.get("tool_call_id") or "")
metadata = dispatch.tool_metadata_by_id.get(tool_call_id) or {}
checkpoint = metadata.get("_context_checkpoint")
if not isinstance(checkpoint, dict):
continue
candidate = str(checkpoint.get("summary") or "").strip()
if candidate:
summary = candidate
return summary
def _error_text(exc: Exception) -> str:
response = getattr(exc, "response", None)
body = (
getattr(exc, "body", None)
or getattr(exc, "doc", None)
or getattr(response, "text", None)
or getattr(exc, "message", None)
or str(exc)
)
return str(body).lower()
def _is_stream_options_unsupported(exc: Exception) -> bool:
text = _error_text(exc)
return any(
marker in text
for marker in (
"stream_options",
"stream options",
"unknown parameter",
"unrecognized request argument",
"unsupported parameter",
"extra inputs are not permitted",
"unexpected keyword",
)
)
def _is_tool_schema_unsupported(exc: Exception) -> bool:
text = _error_text(exc)
return any(
marker in text
for marker in (
"tool",
"function_declaration",
"function declaration",
"function_declarations",
"tool_choice",
"parameters.properties",
"404_not_found",
"404 not_found",
)
)
def _is_image_input_unsupported(exc: Exception) -> bool:
text = _error_text(exc)
return any(
marker in text
for marker in (
"image",
"vision",
"multimodal",
"image_url",
"content type",
"must be a string",
"expected a string",
"expected string",
"invalid type for 'messages",
)
)
__all__ = [
"AgentLoop",
"AgentLoopState",
"InlineThinkFilter",
"LLMCallResult",
"LOOP_STAGE",
"LoopOutcome",
]