Compaction: require verbatim preservation of paths, numbers, and proper nouns (patch + 293-round production evidence)

[luohuayouyisuiliushui]

Contribution per CONTRIBUTING.md (no external PRs accepted): sharing a tested patch with production evidence as a discussion.

正文

问题

默认一次性摘要指令要求 terse bullets，模型为求简会改写掉三类高价值事实的原文：精确文件路径（含扩展名）、具体数值（金额/ID/日期/token 数）、专有名词（脚本/函数/命令/键名）。被恢复的会话最常需要的就是这三类的逐字形态——路径错一个字符找不到文件，金额差一位追错 bug。

改动

COMPACTION_INSTRUCTION 末尾追加一条规则：三类信息逐字保留（禁省略/改写/转述），叙事内容自由压缩；并被限定句闭环到既有 prior-checkpoint 规则——会话后期被取代的值（换掉的版本、重命名路径、修正数字）按 stale-drop 规则丢弃或替换，不跨轮累积。

• 生产（补丁 live 自 2026-10-17；截至 10-19：293 压缩轮 / 32 真实会话）：任务锚点逐字保留率 100%（34/34 探针跨三种任务形状）；有害压缩失败 0；240 次守卫拒绝（not-smaller/truncated 安全设计）+ 50 次上游 500 瞬时报错（全落 10-18 突发时段、全部终态闭合零悬空、随后恢复，10-19 零新增）；台账闭合可复算：293 start = 292 end + 1 orphan，292 end = 242 summary + 50 error-end。
• 回放台架（65K 窗口 × 0.5 阈值，D/G 对照）：压缩版交付质量 ≥ 无压缩参考版（D=G×2 任务、D>G×1 任务）。
• 守卫兼容：not-smaller 与 truncated 守卫继续兜住 stale 累积的体积上限（摘要必须比被遮蔽内容小）。

审查自问自答（预判 maintainer 问题）

1. 与 prior-checkpoint 规则的冲突：已用限定句消解——「never omitted」适用于仍有效的值；被取代的值显式归位到 stale-drop 规则。这是评审后修订加入的（见 commit 历史说明）。
2. README 同步：README.md/README.zh.md 的 fenced instruction block 已同步更新（评审发现项，已修）。
3. 快照：pnpm vitest run packages/compaction/compaction-basic 153/153 通过（rebase 后在新基线复跑，含上游新增 1 例）；该包无 recorded-session 快照钉住指令文本，模型可见文本变化不改变任何既有快照（已实证）。
4. 与既有 62 行规则的关系：62 行是分散举例（paths/commands/errors/identifiers/numbers/signatures），新规则是同类别的强制性收口（proper nouns + never omitted + Every such item must appear verbatim）。两条并存：62 行告诉模型「有哪些类别」，新规则告诉模型「这些类别必须原文出现」。如 maintainer 希望合并为一条，乐意改。
5. commit message 可验证性：数字已全部移到本 PR 描述，commit message 只留机制描述。

测试

新增 vitest 用例断言指令含 4 个关键子串（均为新规则独有文本，与 62 行旧措辞不重叠，无假阳性）。

回滚

恢复 = revert 本 commit。生产环境留有补丁前 .bak（与上游编译产物逐字节一致），可随时还原。

[luohuayouyisuiliushui]

Patch file (git am ready, against master @ 687f282 / v0.2.1-rc.2):

From aff1cbbdc832b4df77bc629835fb51be1207a2b9 Mon Sep 17 00:00:00 2001
From: wjl14 <wjl14@users.noreply.github.com>
Date: Mon, 19 Oct 2026 10:41:03 +0800
Subject: [PATCH] feat(compaction): require verbatim preservation of paths,
 numbers, and proper nouns in summaries

The default one-shot summarizer directive asks for terse bullets, which
models satisfy by paraphrasing away exact file paths, numeric values, and
identifier names - the facts a resumed session most often needs verbatim.
Add an explicit rule requiring those categories to be preserved verbatim
(paths with extensions, numbers/IDs/dates/token counts, proper nouns such
as script/function/command/key names), while leaving narrative content
free to compress.

The rule closes the loop with the prior-checkpoint instruction: values
superseded later in the conversation (replaced versions, renamed paths,
corrected figures) are dropped or replaced rather than carried forward,
so stale anchors do not accumulate across repeated compactions.

Validated in production replay and live sessions over two days; measured
results are summarized in the PR description. README.md/README.zh.md
fenced instruction blocks are synced, and a vitest case pins the new
rule text.

Co-Authored-By: Codex <codex@openai.com>
---
 packages/compaction/compaction-basic/README.md      |  1 +
 packages/compaction/compaction-basic/README.zh.md   |  1 +
 .../compaction/compaction-basic/src/summarizer.ts   |  1 +
 .../compaction-basic/tests/compaction-basic.spec.ts | 13 +++++++++++++
 4 files changed, 16 insertions(+)

diff --git a/packages/compaction/compaction-basic/README.md b/packages/compaction/compaction-basic/README.md
index fa4ae2fb48..86564917df 100644
--- a/packages/compaction/compaction-basic/README.md
+++ b/packages/compaction/compaction-basic/README.md
@@ -223,6 +223,7 @@ Rules:
 - Do NOT mention this summarization request or that the context was compacted.
 - Output only the checkpoint text: do not call any tool or take any other action.
 - If the conversation already contains a <compacted-summary> block, it is a PRIOR checkpoint. Do not copy it forward verbatim: preserve still-true facts, drop stale ones, and merge newer information into a single consolidated summary under the same structure.
+- The following information must be preserved verbatim, never omitted, rewritten, or paraphrased: all file paths and filenames (including extensions), all specific numeric values (numbers, IDs, dates, token counts), all proper nouns (script names, function names, command names, key names). Other narrative content may be compressed. Every such item must appear verbatim in the output. Values superseded later in the conversation (replaced versions, renamed paths, corrected figures) follow the prior-checkpoint rule above: drop or replace them rather than carrying them forward.

Token effect

diff --git a/packages/compaction/compaction-basic/README.zh.md b/packages/compaction/compaction-basic/README.zh.md
index 1cb48123cd..db59679956 100644
--- a/packages/compaction/compaction-basic/README.zh.md
+++ b/packages/compaction/compaction-basic/README.zh.md
@@ -223,6 +223,7 @@ Rules:

• Do NOT mention this summarization request or that the context was compacted.
• Output only the checkpoint text: do not call any tool or take any other action.
• If the conversation already contains a block, it is a PRIOR checkpoint. Do not copy it forward verbatim: preserve still-true facts, drop stale ones, and merge newer information into a single consolidated summary under the same structure.
  +- The following information must be preserved verbatim, never omitted, rewritten, or paraphrased: all file paths and filenames (including extensions), all specific numeric values (numbers, IDs, dates, token counts), all proper nouns (script names, function names, command names, key names). Other narrative content may be compressed. Every such item must appear verbatim in the output. Values superseded later in the conversation (replaced versions, renamed paths, corrected figures) follow the prior-checkpoint rule above: drop or replace them rather than carrying them forward.

#### Token 影响
diff --git a/packages/compaction/compaction-basic/src/summarizer.ts b/packages/compaction/compaction-basic/src/summarizer.ts
index 2d258fa410..77ef0d5be3 100644
--- a/packages/compaction/compaction-basic/src/summarizer.ts
+++ b/packages/compaction/compaction-basic/src/summarizer.ts
@@ -64,6 +64,7 @@ const COMPACTION_INSTRUCTION = [
  '- Do NOT mention this summarization request or that the context was compacted.',
  '- Output only the checkpoint text: do not call any tool or take any other action.',
  `- If the conversation already contains a ${SUMMARY_OPEN_TAG} block, it is a PRIOR checkpoint. Do not copy it forward verbatim: preserve still-true facts, drop stale ones, and merge newer information into a single consolidated summary under the same structure.`,
+  '- The following information must be preserved verbatim, never omitted, rewritten, or paraphrased: all file paths and filenames (including extensions), all specific numeric values (numbers, IDs, dates, token counts), all proper nouns (script names, function names, command names, key names). Other narrative content may be compressed. Every such item must appear verbatim in the output. Values superseded later in the conversation (replaced versions, renamed paths, corrected figures) follow the prior-checkpoint rule above: drop or replace them rather than carrying them forward.',
].join('\n')

/** Framing that makes the replacement user message established context. */
diff --git a/packages/compaction/compaction-basic/tests/compaction-basic.spec.ts b/packages/compaction/compaction-basic/tests/compaction-basic.spec.ts
index 3736aa5c5e..dfdf5a578a 100644
--- a/packages/compaction/compaction-basic/tests/compaction-basic.spec.ts
+++ b/packages/compaction/compaction-basic/tests/compaction-basic.spec.ts
@@ -1460,6 +1460,19 @@ describe('default one-shot summarizer', () => {
    expect(instruction?.type === 'text' ? instruction.text : '').toContain('## Primary Request and Intent')
  })

+  it('requires verbatim preservation of paths, numeric values, and proper nouns in the compaction instruction', async () => {
+    const { adapter, compact } = await summarizerHarness([{ type: 'text', text: 'summary' }])
+    await compact.runSummarize({
+      messages: [createUserMessage({ content: [{ type: 'text', text: 'earlier turn' }], source: { kind: 'test' } })],
+    }, agent(conversation(1), MODEL))
+    const instruction = adapter.lastOptions?.messages.at(-1)?.content[0]
+    const text = instruction?.type === 'text' ? instruction.text : ''
+    expect(text).toContain('preserved verbatim, never omitted, rewritten, or paraphrased')
+    expect(text).toContain('all file paths and filenames (including extensions)')
+    expect(text).toContain('all specific numeric values (numbers, IDs, dates, token counts)')
+    expect(text).toContain('all proper nouns (script names, function names, command names, key names)')
+  })
+
  it('replays the conversation prefix and appends the instruction as the final message', async () => {
    const { adapter, compact } = await summarizerHarness([{ type: 'text', text: 'summary' }])
    const tools = [{ name: 'do_thing', description: 'd', parameters: { type: 'object' } }]
-- 
2.55.0.windows.3

[QIANLING-0831]

摘要里保留精确值，再给摘要附上原文入口，这两步可以配合。dsh-memory-plus 的 dsh-compaction-locator 已实现 Exact Sources 定位符，记录可用的 spill 路径、文件路径和事件 seq 区间，供后续回查。

你这份补丁优先保留当前有效的路径、数字和专有名词；定位符则帮助在摘要省略细节后找到对应证据。联合回归可以检查三件事：当前值是否保留、被替换的旧值是否退出当前状态、遗漏内容是否仍能从原始记录找回。

定位符模块可作为对照实现，适合和这份补丁一起验证恢复路径。

[luohuayouyisuiliushui]

感谢 QIANLING-0831 的补充。「摘要内保活值 + 摘要外留证据入口」的分层定位很清晰，与我们的逐字保真补丁确实互补。三点联合回归口径都认同，先指出一个已有交集：

1. 活值保留：P1 补丁管的就是这一层，路径/数值/专名逐字留在摘要内。生产实测 293 压缩轮、任务锚点逐字保留率 100%，全库回归 100+ 会话真丢失 0。

2. 旧值退出：我们的规则行已带 stale-drop 限定句，被取代的值按既有 prior-checkpoint 规则丢弃或替换，不跨轮累积。「找回旧值不等于当前决策正确」在我们侧已有防线，但把它单列成回归维度是对的，我们会从隐含规则升级为显式检查项。

3. 遗漏可找回：这是我们最想借的一层。我们的会话存储是 append-only 的压缩事件流，每次 compaction/summary 事件都带 seq 和完整摘要文本，prune 只加 shadow 标记不删原文——定位符在我们侧零成本内建。下一步会把这一条做成验证器自动化检查：对每个 lost 项验证能否从会话自身历史按 seq 找回，并区分找回的是当前值还是旧值。

联合回归共建非常欢迎：我们出原始会话样本和验证器，贵方出 locator 实现，两边按同一口径跑、结果互不背书但可对表。

另注：我们当前 reread 注入层因宿主进程的重启策略暂时旁路，P1 提示词补丁不受影响、仍在生效；locator 如需真机触发验证，我们的回归台架随时可用。