diff --git a/changelog.d/maintenance/release-v3851-basereds-codex-filesize.md b/changelog.d/maintenance/release-v3851-basereds-codex-filesize.md
new file mode 100644
index 0000000000..f03ddddb6c
--- /dev/null
+++ b/changelog.d/maintenance/release-v3851-basereds-codex-filesize.md
@@ -0,0 +1 @@
+- **quality:** rebaseline `open-sse/executors/codex.ts` 1552 → 1553 — the +1 landed with #14065 (#13643) without a baseline entry and turned `check:file-size` red on the release tip.
diff --git a/config/quality/file-size-baseline.json b/config/quality/file-size-baseline.json
index d53ff3b863..c82708c425 100644
--- a/config/quality/file-size-baseline.json
+++ b/config/quality/file-size-baseline.json
@@ -1,4 +1,5 @@
 {
+  "_rebaseline_2026_09_18_14065_codex_reasoning_whitelist": "Release-tip drift: open-sse/executors/codex.ts 1552->1553 (+1) from #14065 (fix(codex): whitelist reasoning object keys before the wire, #13643), merged 2026-09-18 without its own rebaseline — the PR->release fast-gates do not run check:file-size, so the tip went red for every train boarding afterwards. Absorbed at the release tip by the /merge-prs captain session (owner-approved train-rebaseline policy, 2026-09-18). Structural shrink tracked in #3501.",
   "_rebaseline_2026_09_18_restore_13643_after_clobber": "Restore of #13643 after e7999c477b clobbered the whitelist at the release tip (see #14062). open-sse/executors/codex.ts 1530->1552 (+22): keep the tip force-rule precedence and restore OpenRouter-style enabled:false plus the reasoning-object key whitelist before the wire. Covered by tests/unit/codex-reasoning-wire-whitelist.test.ts.",
   "_rebaseline_2026_09_03_12648_xkiro_provider": "PR #12648 (feat/provider-xkiro) own growth: src/shared/constants/providers/apikey/gateways.ts +18 lines on top of #12649 (the xkiro APIKEY_PROVIDERS_GATEWAYS catalog entry with hasFree/freeNote/authHint/apiHint documenting the 5M tokens/day free plan, plus the Prettier reflow of two pre-existing >100-col authHint lines (oneminai, freebuff) that lint-staged enforces on any touch of the file; additive data at the existing registry chokepoint, same god-file no-split rationale as prior gateways.ts rebaselines: #11786 seekai, #10987 logfare, #10531 freebuff). Covered by tests/unit/free-provider-xkiro.test.ts (4/4).",
   "_rebaseline_2026_09_15_12643_messages_entry_guard": "#12643 own growth: src/sse/handlers/chat.ts +10 (2490->2500 after syncing the 09-16 base, which itself moved the frozen value). A `messages` array containing a null/non-object entry (e.g. `[null]`) passed every existing entry guard (#5110/#6402/#6407/#6412) and crashed downstream translators/session helpers (openai-to-claude.ts, sessionManager.ts, contextManager.ts's fixToolPairs) reading `.role`/`.content` off the raw entry, surfacing as an HTTP 500 instead of a clean 400. Adds one more entry-shape guard clause to the same chokepoint, extending the existing guard family — same pattern, irreducible call-site wiring (the check itself is a one-line `.some()` predicate, not extractable into its own leaf without hiding the chokepoint). Covered by tests/unit/chat-messages-entry-objects-12643.test.ts (3/3) plus the sibling guard suites (chat-messages-validation-6402.test.ts, chat-non-string-model-6407.test.ts, 22/22, no regression). ATUALIZADO 2026-09-17: o teto foi refixado em 2519 ao mergear o tip atual. O tip sozinho ja esta em 2509 (acima do teto 2500 que esta PR havia fixado contra um tip anterior); o +10 desta PR e o proprio guard de entrada. O excedente do tip (2509>2500) e base-red herdado, nao introduzido aqui.",
@@ -468,7 +469,7 @@
     "open-sse/executors/antigravity.ts": 1665,
     "open-sse/executors/base.ts": 1753,
     "open-sse/executors/chatgpt-web.ts": 5056,
-    "open-sse/executors/codex.ts": 1552,
+    "open-sse/executors/codex.ts": 1553,
     "open-sse/executors/cursor.ts": 1847,
     "open-sse/executors/muse-spark-web.ts": 1405,
     "open-sse/handlers/chatCore.ts": 6287,