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Fix MCP tool call payload handling #888

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Fix MCP tool call payload handling #888

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12 changes: 7 additions & 5 deletions src/avalan/server/routers/mcp.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1054,12 +1054,14 @@ def _tool_call_event_item(event: Event) -> dict[str, JSONValue] | None:
}
if isinstance(event.payload, list) and event.payload:
call = event.payload[0]
elif isinstance(event.payload, dict):
calls = event.payload.get("calls")
if isinstance(calls, list) and calls:
call = calls[0]
else:
Comment on lines +1058 to +1061
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@chatgpt-codex-connector chatgpt-codex-connector bot Jan 10, 2026

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P2 Badge Emit all tool call notifications for multi-call events

When a TOOL_PROCESS payload includes multiple calls (the tool parser can emit payload={"calls": [call1, call2, ...]} when a response contains several tool calls at once), this code only selects calls[0], so _tool_event_notifications emits a notification for the first call and silently drops the rest. That means MCP clients won’t receive tool-call notifications for subsequent calls in the same event, breaking multi-tool responses; this scenario is triggered whenever the model outputs multiple tool calls in a single chunk.

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call = event.payload.get("call")
else:
call = (
event.payload.get("call")
if isinstance(event.payload, dict)
else None
)
call = None
if call is None:
return None
return {
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7 changes: 7 additions & 0 deletions tests/server/mcp_router_test.py
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Original file line number Diff line number Diff line change
Expand Up @@ -337,6 +337,13 @@ def test_tool_call_event_item_variants(self) -> None:
dict_item = mcp_router._tool_call_event_item(dict_event)
self.assertEqual(dict_item["name"], "run")

dict_calls_event = Event(
type=EventType.TOOL_PROCESS,
payload={"calls": [call]},
)
dict_calls_item = mcp_router._tool_call_event_item(dict_calls_event)
self.assertEqual(dict_calls_item["id"], "c1")

none_event = Event(type=EventType.TOOL_PROCESS, payload=None)
self.assertIsNone(mcp_router._tool_call_event_item(none_event))

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