From fbdaa3923d34c00e25f25d0e9ee55a29d8af700b Mon Sep 17 00:00:00 2001
From: LoopX Agent <337587101+loopx-agent@users.noreply.github.com>
Date: Sun, 8 Nov 2026 01:42:57 +0800
Subject: [PATCH] Document a worked Codex compaction usage audit

Signed-off-by: LoopX Agent <337587101+loopx-agent@users.noreply.github.com>
---
 docs/reference/trajectory-assessment.md | 45 +++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/docs/reference/trajectory-assessment.md b/docs/reference/trajectory-assessment.md
index 113a80e01a..d442b71df8 100644
--- a/docs/reference/trajectory-assessment.md
+++ b/docs/reference/trajectory-assessment.md
@@ -1136,6 +1136,51 @@ Registration retains the source hash, and changed or missing sources mark the
 saved capture historical. Re-registering a source with this additional
 projection can create a new pack identity; old packs are never rewritten.
 
+#### Audit one captured session
+
+Suppose a session records two ordinary requests and one compaction request.
+The three response IDs in this synthetic capture give these counts.
+
+| Captured requests | Input | Cached input (subset) | Output |
+| --- | ---: | ---: | ---: |
+| Two ordinary requests | 140 | 80 | 15 |
+| One compaction request | 20 | 10 | 7 |
+| All three requests | 160 | 90 | 22 |
+
+If **Session counters** show 140 input and 15 output, **Request coverage** can
+verify `ordinary_requests` as the counter basis and show the full 160 input
+and 22 output separately. If the counters already show 160 and 22, coverage
+can verify `all_requests`. The compaction row is already part of those totals.
+The checkpoint's copy of the compaction record shares its response ID. Omit
+the copy in the first capture and the session counters still show 140 and 15.
+**Request coverage** reports unavailable.
+[Reconciliation fixture and readback test](../../tests/capabilities/test_trajectory_assessment_store.py)
+
+Use the same Goal and runtime as registration. Set `PACK_ID` to the pack ID
+returned at registration and `OWNER_GOAL` to its owning Goal.
+
+```sh
+loopx --format json benchmark trajectory-packs --goal-id "$OWNER_GOAL" |
+  jq -e --arg pack "$PACK_ID" '
+    .packs[] | select(.pack_id == $pack) | .solver_usage |
+    {artifact_sha256, applicability, projection: (.projection |
+      {session_id, start, end, input_tokens, cached_input_tokens,
+       output_tokens, request_coverage})}'
+```
+
+Keep the pack ID and source hash with the review. Use **Download selected
+usage** to capture the relevant Turn line ranges, then check the request and
+checkpoint in those ranges of the original JSONL. Replaying model behavior
+also requires the original request inputs and runtime.
+
+以一条合成会话为例，两次普通请求合计 140 个输入 token、15 个输出 token，
+一次压缩用去 20 个输入和 7 个输出。若会话计数只覆盖普通请求，查看「请求覆盖」
+里的全量 160 个输入、22 个输出。若会话计数已覆盖全部请求，压缩用量就是其中
+一部分。压缩记录与检查点副本共用一个响应 ID。缺少关联记录时仍可读到会话计数，
+请求级核对会显示不可用。复核时记录 pack ID 和源文件哈希，用「下载所选用量」
+保存相关轮次的行号，再到同一份 JSONL 中核对。回放模型行为还需要原始请求输入
+和运行环境。
+
 ### LoopX packet share of model input
 
 Research → Sources and usage also exposes **LoopX input share**. For the same