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Merged
WillemJiang merged 3 commits into from
May 22, 2026
+70 −7
Merged

fix(middleware): handle repeated tool call ids #3143

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298ee92
fix(middleware): handle repeated tool call ids
ggnnggez May 21, 2026
ca8a68f
add tests
ggnnggez May 22, 2026
40f16f6
refactor(middleware): rely on tool result queues
ggnnggez May 22, 2026
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18 changes: 11 additions & 7 deletions backend/packages/harness/deerflow/agents/middlewares/dangling_tool_call_middleware.py
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@

import json
import logging
from collections import defaultdict, deque
from collections.abc import Awaitable, Callable
from typing import override

Expand Down Expand Up @@ -109,10 +110,10 @@ def _build_patched_messages(self, messages: list) -> list | None:
This normalizes model-bound causal order before provider serialization while
preserving already-valid transcripts unchanged.
"""
tool_messages_by_id: dict[str, ToolMessage] = {}
tool_messages_by_id: dict[str, deque[ToolMessage]] = defaultdict(deque)
for msg in messages:
if isinstance(msg, ToolMessage):
tool_messages_by_id.setdefault(msg.tool_call_id, msg)
tool_messages_by_id[msg.tool_call_id].append(msg)

tool_call_ids: set[str] = set()
for msg in messages:
Expand All @@ -124,7 +125,7 @@ def _build_patched_messages(self, messages: list) -> list | None:
tool_call_ids.add(tc_id)

patched: list = []
consumed_tool_msg_ids: set[str] = set()
consumed_tool_msg_objects: set[int] = set()
patch_count = 0
for msg in messages:
if isinstance(msg, ToolMessage) and msg.tool_call_id in tool_call_ids:
Expand All @@ -136,13 +137,17 @@ def _build_patched_messages(self, messages: list) -> list | None:

for tc in self._message_tool_calls(msg):
tc_id = tc.get("id")
if not tc_id or tc_id in consumed_tool_msg_ids:
if not tc_id:
continue

existing_tool_msg = tool_messages_by_id.get(tc_id)
tool_msg_queue = tool_messages_by_id.get(tc_id)
while tool_msg_queue and id(tool_msg_queue[0]) in consumed_tool_msg_objects:
tool_msg_queue.popleft()

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@ggnnggez ggnnggez May 22, 2026

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Good catch. The deque already guarantees FIFO consumption once a ToolMessage is removed
with popleft(), so the extra object-id tracking is unnecessary here. I removed
consumed_tool_msg_objects and the cleanup loop, and kept the matching logic based on queue
occurrence order only.

existing_tool_msg = tool_msg_queue.popleft() if tool_msg_queue else None
if existing_tool_msg is not None:
patched.append(existing_tool_msg)
consumed_tool_msg_ids.add(tc_id)
consumed_tool_msg_objects.add(id(existing_tool_msg))
else:
patched.append(
ToolMessage(
Expand All @@ -152,7 +157,6 @@ def _build_patched_messages(self, messages: list) -> list | None:
status="error",
)
)
consumed_tool_msg_ids.add(tc_id)
patch_count += 1

if patched == messages:
Expand Down
28 changes: 28 additions & 0 deletions backend/tests/test_dangling_tool_call_middleware.py
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Original file line number Diff line number Diff line change
Expand Up @@ -218,6 +218,34 @@ def test_valid_adjacent_tool_results_are_unchanged(self):

assert mw._build_patched_messages(msgs) is None

def test_reused_tool_call_ids_across_ai_turns_keep_their_own_tool_results(self):
mw = DanglingToolCallMiddleware()
msgs = [
HumanMessage(content="summary", name="summary", additional_kwargs={"hide_from_ui": True}),
_ai_with_tool_calls(
[
_tc("web_search", "web_search:11"),
_tc("web_search", "web_search:12"),
_tc("web_search", "web_search:13"),
]
),
_tool_msg("web_search:11", "web_search"),
_tool_msg("web_search:12", "web_search"),
_tool_msg("web_search:13", "web_search"),
_ai_with_tool_calls(
[
_tc("web_search", "web_search:9"),
_tc("web_search", "web_search:10"),
_tc("web_search", "web_search:11"),
]
),
_tool_msg("web_search:9", "web_search"),
_tool_msg("web_search:10", "web_search"),
_tool_msg("web_search:11", "web_search"),
]

assert mw._build_patched_messages(msgs) is None

def test_tool_results_are_grouped_with_their_own_ai_turn_across_multiple_ai_messages(self):
mw = DanglingToolCallMiddleware()
msgs = [
Expand Down
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