SurfSense/surfsense_backend/app/agents/shared/middleware/otel_span.py
CREDO23 227983a104 refactor(agents): move middleware package to app/agents/shared (slice 5c)
Relocate the entire new_chat/middleware/ package to the shared kernel as one
cohesive unit (it is live shared infrastructure: the multi-agent stack wraps
nearly every middleware via multi_agent_chat/middleware/main_agent/*, and
anonymous_agent consumes it too). Flip 69 live importers across both the
package-path and submodule-path forms.

Shims left for the frozen single-agent stack: a package __init__ re-export plus
submodule shims for permission, skills_backends, and scoped_model_fallback
(the three imported via submodule path by chat_deepagent/subagents).

Cycle break: importing shared.middleware previously reached back into
new_chat.tools at module load, which dragged in new_chat.__init__ ->
chat_deepagent -> the middleware shim -> half-initialized shared.middleware.
Made action_log's ToolDefinition import TYPE_CHECKING-only and
tool_call_repair's INVALID_TOOL_NAME import function-local. These tools-package
back-edges fully resolve in slice 6.

Asset note: skills_backends._default_builtin_root now walks to
app/agents/new_chat/skills/builtin (the skills/ tree migrates in slice 7).
2026-06-04 13:00:41 +02:00

285 lines
10 KiB
Python

"""
OpenTelemetry span middleware for the SurfSense ``new_chat`` agent.
Wraps both ``model.call`` (LLM invocations) and ``tool.call`` (tool
executions) with OTel spans, attaching low-cardinality span names and
high-cardinality identifiers as attributes.
This middleware is intentionally a thin adapter over
:mod:`app.observability.otel`; when OTel is not configured all spans
collapse to no-ops and the wrapper adds <1µs overhead per call. When
OTel **is** configured (``OTEL_EXPORTER_OTLP_ENDPOINT`` set), every
model and tool call gets a span with the standard attributes our
dashboards expect.
"""
from __future__ import annotations
import logging
import time
from collections.abc import Awaitable, Callable
from typing import TYPE_CHECKING, Any
from langchain.agents.middleware import AgentMiddleware
from langchain_core.messages import AIMessage, ToolMessage
from app.observability import metrics as ot_metrics, otel as ot
if TYPE_CHECKING: # pragma: no cover — type-only
from langchain.agents.middleware.types import (
ModelRequest,
ModelResponse,
ToolCallRequest,
)
from langgraph.types import Command
logger = logging.getLogger(__name__)
class OtelSpanMiddleware(AgentMiddleware):
"""Emit ``model.call`` and ``tool.call`` OTel spans for every invocation.
Should be placed near the **outer** end of the middleware list so
that the spans encompass retry/fallback wrapper effects (i.e. ``N``
model.call spans for ``N`` retry attempts) but inside any concurrency/
auth gate. Empirically this means **between** ``BusyMutex`` and
``RetryAfter``.
"""
def __init__(self, *, instrumentation_name: str = "surfsense.new_chat") -> None:
super().__init__()
self._instrumentation_name = instrumentation_name
# ------------------------------------------------------------------
# Model call spans
# ------------------------------------------------------------------
async def awrap_model_call(
self,
request: ModelRequest,
handler: Callable[[ModelRequest], Awaitable[ModelResponse | AIMessage | Any]],
) -> ModelResponse | AIMessage | Any:
if not ot.is_enabled():
return await handler(request)
model_id, provider = _resolve_model_attrs(request)
t0 = time.perf_counter()
with ot.model_call_span(model_id=model_id, provider=provider) as sp:
_annotate_model_request(sp, model_id=model_id, provider=provider)
try:
result = await handler(request)
except Exception:
ot_metrics.record_model_call_duration(
(time.perf_counter() - t0) * 1000,
model=model_id,
provider=provider,
)
# span context manager records + re-raises
raise
else:
input_tokens, output_tokens = _annotate_model_response(
sp,
result,
model_id=model_id,
provider=provider,
)
ot_metrics.record_model_call_duration(
(time.perf_counter() - t0) * 1000,
model=model_id,
provider=provider,
)
ot_metrics.record_model_token_usage(
input_tokens=input_tokens,
output_tokens=output_tokens,
model=model_id,
provider=provider,
)
return result
# ------------------------------------------------------------------
# Tool call spans
# ------------------------------------------------------------------
async def awrap_tool_call(
self,
request: ToolCallRequest,
handler: Callable[[ToolCallRequest], Awaitable[ToolMessage | Command[Any]]],
) -> ToolMessage | Command[Any]:
if not ot.is_enabled():
return await handler(request)
tool_name = _resolve_tool_name(request)
input_size = _resolve_input_size(request)
t0 = time.perf_counter()
with ot.tool_call_span(tool_name, input_size=input_size) as sp:
try:
result = await handler(request)
except Exception:
ot_metrics.record_tool_call_duration(
(time.perf_counter() - t0) * 1000,
tool_name=tool_name,
)
ot_metrics.record_tool_call_error(tool_name=tool_name)
raise
errored = _annotate_tool_result(sp, result)
ot_metrics.record_tool_call_duration(
(time.perf_counter() - t0) * 1000,
tool_name=tool_name,
)
if errored:
ot_metrics.record_tool_call_error(tool_name=tool_name)
return result
# ---------------------------------------------------------------------------
# Attribute helpers (kept defensive; we never want OTel bookkeeping to break
# a real model/tool call).
# ---------------------------------------------------------------------------
def _resolve_model_attrs(request: Any) -> tuple[str | None, str | None]:
"""Extract ``model.id`` and ``model.provider`` from a ``ModelRequest``."""
model_id: str | None = None
provider: str | None = None
try:
model = getattr(request, "model", None)
if model is None:
return None, None
# langchain BaseChatModel exposes a few different identifiers
for attr in ("model_name", "model", "model_id"):
value = getattr(model, attr, None)
if value:
model_id = str(value)
break
# provider sometimes lives on ``_llm_type`` (legacy) or ``provider``
for attr in ("provider", "_llm_type"):
value = getattr(model, attr, None)
if value:
provider = str(value)
break
except Exception: # pragma: no cover — defensive
pass
return model_id, provider
def _resolve_tool_name(request: Any) -> str:
try:
tool = getattr(request, "tool", None)
if tool is not None:
name = getattr(tool, "name", None)
if isinstance(name, str) and name:
return name
# Fall back to the tool_call dict
call = getattr(request, "tool_call", None) or {}
name = call.get("name") if isinstance(call, dict) else None
if isinstance(name, str) and name:
return name
except Exception: # pragma: no cover — defensive
pass
return "unknown"
def _resolve_input_size(request: Any) -> int | None:
try:
call = getattr(request, "tool_call", None)
if not isinstance(call, dict) or not call:
return None
args = call.get("args")
if args is None:
return None
return len(repr(args))
except Exception: # pragma: no cover — defensive
return None
def _annotate_model_request(
span: Any, *, model_id: str | None, provider: str | None
) -> None:
try:
span.set_attribute("gen_ai.operation.name", "chat")
if model_id:
span.set_attribute("gen_ai.request.model", model_id)
if provider:
span.set_attribute("gen_ai.provider.name", provider)
except Exception: # pragma: no cover — defensive
pass
def _annotate_model_response(
span: Any,
result: Any,
*,
model_id: str | None = None,
provider: str | None = None,
) -> tuple[int | None, int | None]:
"""Best-effort: attach prompt/completion token counts when available."""
input_tokens: int | None = None
output_tokens: int | None = None
try:
# ModelResponse may be a dataclass with .result containing AIMessage
msg: Any
if isinstance(result, AIMessage):
msg = result
else:
inner = getattr(result, "result", None)
msg = inner[-1] if isinstance(inner, list) and inner else inner
if msg is None:
return None, None
if provider:
span.set_attribute("gen_ai.provider.name", provider)
if model_id:
span.set_attribute("gen_ai.request.model", model_id)
response_model = getattr(msg, "response_metadata", {}) or {}
if isinstance(response_model, dict):
response_model = (
response_model.get("model_name")
or response_model.get("model")
or response_model.get("model_id")
)
if not response_model:
response_model = model_id
if response_model:
span.set_attribute("gen_ai.response.model", str(response_model))
span.set_attribute("gen_ai.operation.name", "chat")
usage = getattr(msg, "usage_metadata", None) or {}
if isinstance(usage, dict):
if (n := usage.get("input_tokens")) is not None:
input_tokens = int(n)
span.set_attribute("gen_ai.usage.input_tokens", input_tokens)
if (n := usage.get("output_tokens")) is not None:
output_tokens = int(n)
span.set_attribute("gen_ai.usage.output_tokens", output_tokens)
if (n := usage.get("total_tokens")) is not None:
span.set_attribute("gen_ai.usage.total_tokens", int(n))
tool_calls = getattr(msg, "tool_calls", None) or []
span.set_attribute("model.tool_calls", len(tool_calls))
except Exception: # pragma: no cover — defensive
pass
return input_tokens, output_tokens
def _annotate_tool_result(span: Any, result: Any) -> bool:
errored = False
try:
if isinstance(result, ToolMessage):
content = (
result.content
if isinstance(result.content, str)
else repr(result.content)
)
span.set_attribute("tool.output.size", len(content))
status = getattr(result, "status", None)
if isinstance(status, str):
span.set_attribute("tool.status", status)
errored = status.lower() == "error"
kwargs = getattr(result, "additional_kwargs", None) or {}
if isinstance(kwargs, dict) and kwargs.get("error"):
span.set_attribute("tool.error", True)
errored = True
except Exception: # pragma: no cover — defensive
pass
return errored
__all__ = ["OtelSpanMiddleware"]