From 5664b9d413bf3419ba7ea8031a0b808f069f75ff Mon Sep 17 00:00:00 2001
From: ppyt <1580259346@qq.com>
Date: Fri, 3 Apr 2026 11:21:58 +0800
Subject: [PATCH] fix: inject longTermBackground into memory prompt (#1734)
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The format_memory_for_injection function only processed recentMonths and
earlierContext from the history section, silently dropping longTermBackground.

The LLM writes longTermBackground correctly and it persists to memory.json,
but it was never injected into the system prompt — making the user's
long-term background invisible to the AI.

Add the missing field handling and a regression test.

Co-authored-by: ppyt <14163465+ppyt@users.noreply.github.com>
---
 .../harness/deerflow/agents/memory/prompt.py  |  4 ++++
 backend/tests/test_memory_prompt_injection.py | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/backend/packages/harness/deerflow/agents/memory/prompt.py b/backend/packages/harness/deerflow/agents/memory/prompt.py
index e0c04b77e..47b35e2ae 100644
--- a/backend/packages/harness/deerflow/agents/memory/prompt.py
+++ b/backend/packages/harness/deerflow/agents/memory/prompt.py
@@ -246,6 +246,10 @@ def format_memory_for_injection(memory_data: dict[str, Any], max_tokens: int = 2
         if earlier.get("summary"):
             history_sections.append(f"Earlier: {earlier['summary']}")
 
+        background = history_data.get("longTermBackground", {})
+        if background.get("summary"):
+            history_sections.append(f"Background: {background['summary']}")
+
         if history_sections:
             sections.append("History:\n" + "\n".join(f"- {s}" for s in history_sections))
 
diff --git a/backend/tests/test_memory_prompt_injection.py b/backend/tests/test_memory_prompt_injection.py
index d33b69a92..7c3ad85c4 100644
--- a/backend/tests/test_memory_prompt_injection.py
+++ b/backend/tests/test_memory_prompt_injection.py
@@ -154,3 +154,22 @@ def test_format_memory_renders_correction_without_source_error_normally() -> Non
 
     assert "Use make dev for local development." in result
     assert "avoid:" not in result
+
+
+def test_format_memory_includes_long_term_background() -> None:
+    """longTermBackground in history must be injected into the prompt."""
+    memory_data = {
+        "user": {},
+        "history": {
+            "recentMonths": {"summary": "Recent activity summary"},
+            "earlierContext": {"summary": "Earlier context summary"},
+            "longTermBackground": {"summary": "Core expertise in distributed systems"},
+        },
+        "facts": [],
+    }
+
+    result = format_memory_for_injection(memory_data, max_tokens=2000)
+
+    assert "Background: Core expertise in distributed systems" in result
+    assert "Recent: Recent activity summary" in result
+    assert "Earlier: Earlier context summary" in result