diff --git a/reme/steps/benchmark/lme/auto_memory.py b/reme/steps/benchmark/lme/auto_memory.py
index a27cb45c..bf3a678b 100644
--- a/reme/steps/benchmark/lme/auto_memory.py
+++ b/reme/steps/benchmark/lme/auto_memory.py
@@ -131,3 +131,31 @@ class LmeAutoMemoryStep(AutoMemoryStep):
             [item if not isinstance(item, dict) else dict(item) for item in raw_messages],
         )
         return [self._to_msg(item) for item in interpolated]
+
+    def _format_history(self, messages: list[Msg]) -> str:
+        # Annotate every turn with its physical line number in the session
+        # file so the agent can cite information sources as
+        # [[<session file path>#L<start>-L<end>]]. A LongMemEval session is
+        # already in chronological order, matching the one-message-per-line
+        # layout written by AutoMemoryStep._save_session_messages, so number
+        # each turn by its position in the list (no re-sorting).
+        session_id = self.context.get("session_id", "") if self.context is not None else ""
+        source_path = self._session_source_path(session_id)
+
+        turns: list[str] = []
+        for line, msg in enumerate(messages, start=1):
+            text = (msg.get_text_content() or "").strip()
+            if not text:
+                continue
+            speaker = msg.name or msg.role or "?"
+            turns.append(f"[L{line} | {speaker} @ {msg.created_at}]\n{text}")
+
+        if not turns:
+            return "(empty)"
+
+        preamble = (
+            f"Source file: {source_path}\n"
+            f"(Each turn below is prefixed with [Ln] = its line number in the source file; "
+            "copy these numbers verbatim into source markers.)"
+        )
+        return preamble + "\n\n" + "\n\n".join(turns)
diff --git a/reme/steps/benchmark/lme/auto_memory.yaml b/reme/steps/benchmark/lme/auto_memory.yaml
index a9c59c27..78e88bb9 100644
--- a/reme/steps/benchmark/lme/auto_memory.yaml
+++ b/reme/steps/benchmark/lme/auto_memory.yaml
@@ -7,6 +7,13 @@ system_prompt: |
   2. **Force Disambiguation**: Absolutely PROHIBIT using pronouns (he, she, it, they, this, that) or relative time references (yesterday, today, last week, tomorrow, recently). Always use full names, explicit dates, and specific references.
   3. **Lossless Information**: Every recorded fact must be a complete, independent, understandable statement. A reader with no prior context must be able to understand each entry on its own.
   4. **Verbatim Preservation**: Quote original wording, numbers, URLs, commands, and code snippets exactly as stated.
+  5. **Source Attribution**: Mark the source of factual content with a wikilink-style marker built from the `Source file` path (copied verbatim) and the `[Ln]` line numbers of the turns the fact was derived from. The EXACT format is `[[<path>#L<start>-L<end>(,L<start>-L<end>)*]]`, e.g. `[[session/dialog/s1.jsonl#L1-L2]]`.
+     - **No `Source` label**: write the marker DIRECTLY at the end of the entry (or heading). Do NOT prefix it with `Source`, `Source:`, `source`, `来源`, or any other word — output only the bare `[[...]]` marker.
+     - **Double brackets + `#` + `L`-prefixed hyphen ranges**: EVERY marker MUST be wrapped in DOUBLE square brackets `[[...]]`, begin with the full session file path, then a hash `#`, then one or more line ranges. Each range is `L<start>-L<end>` — BOTH endpoints carry the `L` prefix and are joined by a hyphen `-` (NEVER a colon). A single line is written as a one-line range, e.g. `L41-L41`. This applies to EVERY comma-separated range too: `L69-L72,L77` is INVALID — write `L69-L72,L77-L77`. Multiple ranges of the same file go into ONE marker, separated by commas with NO spaces. ✗ WRONG: `[session/dialog/....jsonl:29-34]` (old single-bracket colon format), `[[...jsonl#29-34]]` (numbers missing `L`), `[[...jsonl#L29-34]]` (end missing `L`), `[[...jsonl#L29:L34]]` (colon instead of hyphen), `[[L29-L34]]` (path dropped), `[[...jsonl#L41]]` (bare single line — write `L41-L41`), `[[...jsonl#L69-L72,L77]]` (second range is a bare line — write `L77-L77`), `Source: [[...jsonl#L29-L34]]` (label added). ✓ RIGHT: `[[session/dialog/s1.jsonl#L29-L34,L53-L58]]`.
+     - **Line numbers come from the `[Ln]` labels**: the `[Ln]` label prefixing each input turn (e.g. `[L29 | user @ ...]`) is that message's line number in the ORIGINAL source file — copy those numbers verbatim. Newlines inside a message's own content do NOT affect its line number.
+     - **Merge same-file ranges into ONE marker**: instead of back-to-back markers like `[[...jsonl#L1-L2]][[...jsonl#L5-L6]]`, write a single marker with comma-separated ranges `[[...jsonl#L1-L2,L5-L6]]`.
+     - **Hoist shared markers, never repeat**: when several consecutive bullets share the SAME marker, do NOT append it to every bullet. Attach ONE marker to the group instead — either append it to the section heading (where it then covers every bullet beneath that heading until a different marker appears), or merge those bullets into a single entry carrying one trailing marker. Repeating an identical marker across sibling bullets is PROHIBITED — it wastes tokens.
+     - **Cite enough self-contained context**: the cited line range must be self-contained. Do NOT cite only the single line that states the key detail; widen the range to include the surrounding turns (e.g. the question or setup turn that gives the fact its meaning) so that a reader who opens only that line range understands the fact correctly and is not misled by missing context.
 
   ## What to Extract
 
@@ -22,7 +29,7 @@ system_prompt: |
 
   ## Body Format
 
-  Use structured sections with headings. Each factual entry should be a standalone bullet point — complete and self-contained. Group entries by topic. Include a `## Metadata` section at the end with extracted keywords, persons, entities, and topics.
+  Use structured sections with headings. Each factual entry should be a standalone bullet point — complete and self-contained. Group entries by topic. Attach source markers coarsely (see the Source Attribution principle): prefer ONE marker per section heading or per grouped entry, write only the bare `[[...]]` marker with no `Source` label, and never repeat an identical marker across consecutive bullets. Do NOT add a `## Metadata` section.
 
   ## Frontmatter Rules
 
@@ -46,6 +53,13 @@ system_prompt_zh: |
   2. **强制消歧**：绝对禁止使用代词（他、她、它、他们、这个、那个）或相对时间（昨天、今天、上周、明天、最近）。必须使用全名、明确日期和具体引用。
   3. **无损信息**：每条记录的事实必须是完整的、独立的、可理解的陈述。没有上下文的读者必须能单独理解每条记录。
   4. **原文保留**：逐字引用原始措辞、数字、URL、命令和代码片段。
+  5. **来源标注**：为事实内容标注来源，使用 wikilink 风格的标记，由对话中显示的 `Source file` 路径（逐字复制）与该事实所依据对话轮次的 `[Ln]` 行号拼成。格式**必须**为 `[[<path>#L<start>-L<end>(,L<start>-L<end>)*]]`，例如 `[[session/dialog/s1.jsonl#L1-L2]]`。
+     - **不要 `Source` 标签**：把标记**直接**写在条目（或标题）末尾。不要在前面加 `Source`、`Source:`、`source`、`来源` 或任何其他词——只输出裸的 `[[...]]` 标记。
+     - **双层方括号 + `#` + 带 `L` 前缀的连字符区间**：每个标记都**必须**用双层方括号 `[[...]]` 包裹，以完整的 session 文件路径开头，然后接 `#`，再接一个或多个行号区间。每个区间写作 `L<start>-L<end>`——两端都带 `L` 前缀，用连字符 `-` 连接（**绝不**用冒号）。单行引用写成单行区间，如 `L41-L41`；逗号分隔的每一个区间也同样适用：`L69-L72,L77` 是**无效的**，应写成 `L69-L72,L77-L77`。同一文件的多个区间放入**同一个**标记，用逗号分隔且不加空格。✗ 错误：`[session/dialog/....jsonl:29-34]`（旧的单括号冒号格式）、`[[...jsonl#29-34]]`（数字缺 `L`）、`[[...jsonl#L29-34]]`（末端缺 `L`）、`[[...jsonl#L29:L34]]`（用了冒号）、`[[L29-L34]]`（丢了路径）、`[[...jsonl#L41]]`（裸单行，应写 `L41-L41`）、`[[...jsonl#L69-L72,L77]]`（第二个区间是裸单行，应写 `L77-L77`）、`Source: [[...jsonl#L29-L34]]`（加了标签）。✓ 正确：`[[session/dialog/s1.jsonl#L29-L34,L53-L58]]`。
+     - **行号来自 `[Ln]` 标签**：输入中每条对话轮次前的 `[Ln]` 标签（如 `[L29 | user @ ...]`）就是该消息在**原始**源文件中的行号——请逐字复制这些数字。消息正文内部的换行不影响其行号。
+     - **同一文件多区间合并进一个标记**：不要写成相邻的多个标记 `[[...jsonl#L1-L2]][[...jsonl#L5-L6]]`，而要写成用逗号分隔区间的单个标记 `[[...jsonl#L1-L2,L5-L6]]`。
+     - **上提共享标记，绝不重复**：当连续多个条目共享**相同**标记时，不要给每个条目都追加。而是给整组只标注一个标记——要么把标记追加到分节标题上（此时它覆盖该标题下、直到出现不同标记之前的所有条目），要么把这些条目合并为一条并只在末尾带一个标记。在同级条目上重复相同标记是**被禁止的**——会浪费 token。
+     - **引用充分且自洽的上下文**：所标注的行号区间必须自洽完整。不要只标注陈述关键信息的那一句，要把区间扩大到包含周边轮次（例如赋予该事实意义的提问或铺垫轮次），使得仅打开该行号区间的读者也能正确理解这条事实，不会因缺失上下文而断章取义。
 
   ## 提取什么
 
@@ -61,7 +75,7 @@ system_prompt_zh: |
 
   ## 正文格式
 
-  使用带标题的结构化分节。每条事实记录应是独立的列表项——完整且自包含。按主题分组。在末尾添加 `## Metadata` 部分，列出提取的关键词、人物、实体和主题。
+  使用带标题的结构化分节。每条事实记录应是独立的列表项——完整且自包含。按主题分组。粗粒度地标注来源（见来源标注原则）：优先每个分节标题或每组条目只用一个标记，只写裸的 `[[...]]` 标记且不带 `Source` 标签，并且绝不在连续条目上重复相同标记。不要添加 `## Metadata` 部分。
 
   ## Frontmatter 规则
 
@@ -81,6 +95,7 @@ user_message_create: |
   Today: {today}
   Extra hint: {note}
   Session ID: {session_id}
+  Session file: {session_file}   ← copy THIS exact path into every source marker (e.g. `[[{session_file}#L1-L2,L5-L6]]`)
 
   # Recent Conversation
 
@@ -115,15 +130,8 @@ user_message_create: |
 
   ⚠️ CRITICAL: You MUST invoke `daily_write` as a **tool call** (function call). Do NOT write `daily_write name=...` as plain text — that will NOT execute the tool and NO memory will be saved.
 
-  Body requirements:
-  - Each factual entry must be a complete, independent, self-contained statement (lossless restatement).
-  - PROHIBIT pronouns (he/she/it/they/this/that) — use full names and explicit references.
-  - PROHIBIT relative time (yesterday/today/last week) — use absolute dates (YYYY-MM-DD).
-  - Group entries by topic with headings.
-  - End with a `## Metadata` section containing: keywords, persons, entities, topic.
-
-  Filename and description rules:
-  - `name`: concise, stable topic/event filename stem in kebab-case. No date, no slash/backslash, no `< > : " | ? *`.
+  Body requirements — follow the system prompt's Extraction Principles, Body Format, and Frontmatter Rules (lossless entries; no pronouns; absolute dates; grouped by topic; no `## Metadata`). Two rules that MUST NOT be violated:
+  - Source markers: put a bare `[[session/dialog/....jsonl#L1-L2,L5-L6]]` at the END of an entry or heading — double brackets, full path + `#`, `L`-prefixed hyphen ranges, no `Source` label, coarse (hoist a shared marker, never repeat it across bullets), and cite a self-contained line range copied verbatim from the `[Ln]` labels.
   - `description`: a thorough, lossless summary — specific enough that the description alone conveys all key information.
 
   ## Step 3 — Summary
@@ -137,6 +145,7 @@ user_message_create_zh: |
   今天：{today}
   额外提示：{note}
   Session ID：{session_id}
+  Session 文件：{session_file}   ← 请把这个完整路径原样复制进每个来源标记（例如 `[[{session_file}#L1-L2,L5-L6]]`）
 
   # 最近的对话
 
@@ -171,15 +180,8 @@ user_message_create_zh: |
 
   ⚠️ 关键：你**必须**以**工具调用**（函数调用）方式调用 `daily_write`。不要将 `daily_write name=...` 作为纯文本输出——那样**不会**执行工具，也**不会**保存任何记忆。
 
-  正文要求：
-  - 每条事实记录必须是完整的、独立的、自包含的陈述（无损复述）。
-  - 禁止使用代词（他/她/它/他们/这个/那个）——必须使用全名和明确引用。
-  - 禁止使用相对时间（昨天/今天/上周）——必须使用绝对日期（YYYY-MM-DD）。
-  - 按主题分组并使用标题。
-  - 末尾添加 `## Metadata` 部分，包含：keywords、persons、entities、topic。
-
-  文件名和描述规则：
-  - `name`：简洁、稳定的主题/事件文件名 stem，采用 kebab-case。不含日期、不含 slash/反斜杠、不含 `< > : " | ? *`。
+  正文要求——遵循 system prompt 的提取原则、正文格式与 Frontmatter 规则（无损；不用代词；绝对日期；按主题分组；无 `## Metadata`）。以下两条**绝不能违反**：
+  - 来源标记：在条目或标题**末尾**放一个裸的 `[[session/dialog/....jsonl#L1-L2,L5-L6]]`——双层方括号、完整路径 + `#`、带 `L` 前缀的连字符区间、无 `Source` 标签、粒度粗（上提共享标记、绝不在连续条目上重复），且行号逐字复制自 `[Ln]` 标签、引用自洽完整的行号区间。
   - `description`：详尽的无损总结——具体到仅凭 description 就能传达全部核心信息。
 
   ## 步骤 3 — 总结
@@ -194,6 +196,7 @@ user_message_update: |
   Today: {today}
   Extra hint: {note}
   Target path: {note_path}
+  Session file: {session_file}   ← copy THIS exact path into every source marker (e.g. `[[{session_file}#L1-L2,L5-L6]]`)
 
   # Recent Conversation
 
@@ -219,19 +222,16 @@ user_message_update: |
 
   The note already has content. Extract new information from the conversation and merge into it.
 
-  Extraction rules (apply to ALL new entries):
-  - Each new fact must be a complete, independent, self-contained statement (lossless restatement).
-  - PROHIBIT pronouns (he/she/it/they/this/that) — use full names and explicit references.
-  - PROHIBIT relative time (yesterday/today/last week) — use absolute dates (YYYY-MM-DD).
+  Extraction rules (apply to ALL new entries) — follow the system prompt's Extraction Principles and Body Format (lossless; no pronouns; absolute dates; grouped by topic). Source markers MUST be a bare `[[session/dialog/....jsonl#L1-L2,L5-L6]]` — double brackets, full path + `#`, `L`-prefixed hyphen ranges copied verbatim from the `[Ln]` labels, no `Source` label, coarse (never repeated across bullets), self-contained range.
 
   Merge rules:
   - **Timeline / history entries**: append only, never delete existing entries.
   - **Current-state entries** (progress, blockers, next steps, open questions): rewrite the entire section to reflect the latest snapshot.
   - **Everything else**: merge and deduplicate — keep all old facts, add new facts, remove exact duplicates.
-  - **Metadata section**: merge keywords, persons, entities, topics — union of old and new values.
 
   Execution:
   1. **Call the `edit` tool** for each section that needs updating, with parameters: `path`="{note_path}", `old`=<original fragment>, `new`=<replacement fragment>. You may call `edit` multiple times. Each call MUST be a tool call, not text.
+     - ⚠️ `edit` is for the note BODY only. NEVER touch the frontmatter block (the `---`-delimited YAML at the top of the file) with `edit` — a malformed YAML edit corrupts the whole note. All frontmatter changes MUST go through the `frontmatter_update` tool.
   2. After body changes, **call the `frontmatter_update` tool** to refresh frontmatter, with parameters: `path`="{note_path}", `metadata`={{"name": "<updated filename stem>", "description": "<updated summary>"}}.
      - Keep the existing `name` only when it is already the best concise topic/event filename stem. The system will rename the file after your final response.
      - Do not add today's date or the daily directory date to `name`.
@@ -241,16 +241,7 @@ user_message_update: |
 
   The file exists but its body is empty. Extract and write the full content by **calling the `write` tool** with parameters: `path`="{note_path}", `name`=<name>, `description`=<description>, `content`=<body>.
 
-  Body requirements:
-  - Each factual entry must be a complete, independent, self-contained statement.
-  - PROHIBIT pronouns — use full names and explicit references.
-  - PROHIBIT relative time — use absolute dates (YYYY-MM-DD).
-  - Group entries by topic with headings.
-  - End with a `## Metadata` section containing: keywords, persons, entities, topic.
-
-  Filename and description rules:
-  - `name`: concise, stable topic/event filename stem in kebab-case. No date.
-  - `description`: a thorough, lossless summary — the description alone should convey all key information.
+  Body requirements — follow the system prompt's Extraction Principles, Body Format, and Frontmatter Rules (lossless; no pronouns; absolute dates; grouped by topic; no `## Metadata`). Source markers MUST be a bare `[[session/dialog/....jsonl#L1-L2,L5-L6]]` — double brackets, full path + `#`, `L`-prefixed hyphen ranges copied verbatim from the `[Ln]` labels, no `Source` label, coarse (never repeated across bullets), self-contained range. `description` must be a thorough, lossless summary that alone conveys all key information.
 
   ## Step 4 — Summary
 
@@ -265,6 +256,7 @@ user_message_update_zh: |
   今天：{today}
   额外提示：{note}
   目标路径：{note_path}
+  Session 文件：{session_file}   ← 请把这个完整路径原样复制进每个来源标记（例如 `[[{session_file}#L1-L2,L5-L6]]`）
 
   # 最近的对话
 
@@ -290,19 +282,16 @@ user_message_update_zh: |
 
   笔记已有内容。从对话中提取新信息并合并进去。
 
-  提取规则（适用于所有新条目）：
-  - 每条新事实必须是完整的、独立的、自包含的陈述（无损复述）。
-  - 禁止使用代词（他/她/它/他们/这个/那个）——必须使用全名和明确引用。
-  - 禁止使用相对时间（昨天/今天/上周）——必须使用绝对日期（YYYY-MM-DD）。
+  提取规则（适用于所有新条目）——遵循 system prompt 的提取原则与正文格式（无损；不用代词；绝对日期；按主题分组）。来源标记必须是裸的 `[[session/dialog/....jsonl#L1-L2,L5-L6]]`——双层方括号、完整路径 + `#`、带 `L` 前缀的连字符区间（行号逐字复制自 `[Ln]` 标签）、无 `Source` 标签、粒度粗（不在连续条目上重复）、自洽完整的行号区间。
 
   合并规则：
   - **时间线 / 历史条目**：仅追加，永远不删除已有条目。
   - **当下状态类条目**（进度、卡点、下一步、未决问题）：整段重写，反映最新快照。
   - **其余内容**：合并去重——保留全部旧事实，添加新事实，去除完全重复项。
-  - **Metadata 部分**：合并 keywords、persons、entities、topics——取旧值和新值的并集。
 
   执行：
   1. **调用 `edit` 工具**更新需要修改的部分，参数为：`path`="{note_path}"、`old`=<原文片段>、`new`=<替换片段>。可以多次调用 `edit`。每次调用必须是工具调用，不是文本。
+     - ⚠️ `edit` 只能用于笔记**正文**。**绝不**要用 `edit` 碰 frontmatter 块（文件顶部由 `---` 包围的 YAML）——格式错误的 YAML 会损坏整个笔记。所有 frontmatter 修改都必须通过 `frontmatter_update` 工具。
   2. 正文变更后，**调用 `frontmatter_update` 工具**刷新 frontmatter，参数为：`path`="{note_path}"、`metadata`={{"name": "<更新后的文件名 stem>", "description": "<更新后的总结>"}}。
      - 只有当前 `name` 已经是最合适的简洁主题/事件文件名 stem 时才保留。系统会在你最终回复后负责重命名文件。
      - 不要在 `name` 中加入今天日期或日记目录日期。
@@ -312,16 +301,7 @@ user_message_update_zh: |
 
   文件存在但正文为空。提取并**调用 `write` 工具**一次性写入完整内容，参数为：`path`="{note_path}"、`name`=<name>、`description`=<description>、`content`=<正文>。
 
-  正文要求：
-  - 每条事实记录必须是完整的、独立的、自包含的陈述。
-  - 禁止使用代词——必须使用全名和明确引用。
-  - 禁止使用相对时间——必须使用绝对日期（YYYY-MM-DD）。
-  - 按主题分组并使用标题。
-  - 末尾添加 `## Metadata` 部分，包含：keywords、persons、entities、topic。
-
-  文件名和描述规则：
-  - `name`：简洁、稳定的主题/事件文件名 stem，采用 kebab-case。不含日期。
-  - `description`：详尽的无损总结——仅凭 description 就应能传达全部核心信息。
+  正文要求——遵循 system prompt 的提取原则、正文格式与 Frontmatter 规则（无损；不用代词；绝对日期；按主题分组；无 `## Metadata`）。来源标记必须是裸的 `[[session/dialog/....jsonl#L1-L2,L5-L6]]`——双层方括号、完整路径 + `#`、带 `L` 前缀的连字符区间（行号逐字复制自 `[Ln]` 标签）、无 `Source` 标签、粒度粗（不在连续条目上重复）、自洽完整的行号区间。`description` 必须是仅凭自身即可传达全部核心信息的详尽无损总结。
 
   ## 步骤 4 — 总结