diff --git a/docs/architecture/rfcs/monorepo-distribution-split-v0.md b/docs/architecture/rfcs/monorepo-distribution-split-v0.md
index c7c151b8c4..0ccbab1029 100644
--- a/docs/architecture/rfcs/monorepo-distribution-split-v0.md
+++ b/docs/architecture/rfcs/monorepo-distribution-split-v0.md
@@ -2567,6 +2567,50 @@ R0/V10/R1, D2/D5/D6/D3, context/model/split-install, PostgreSQL host/wheel and
 full-cost/adoption requirements remain open. No main merge or host upgrade is
 included.
 
+### 2026-11-08 — Synthetic Host UTF-8 recovery qualification
+
+The Windows CPython 3.11 CI arm of #8360 fails six existing original-task
+revalidation cases. Its synthetic Python Host inherits a locale decoder for a
+pipe, while the existing generic Host transport sends UTF-8 JSON. A disposable
+File-provider counterprobe changes only that Host decoder: CP1252 produces
+`host_failure` without `task_failure`; UTF-8 reaches the independent artifact
+validator and produces `validation_failed` at `task_postcondition`, with
+`revalidate_cached_result`. The source macOS arm independently passes all 12
+existing revalidation cases. These observations locate a fixture mismatch;
+they do not justify widening production failure classification.
+
+Fixture commit `a4ce613585fdb329ba3600f0ede768864214ed84`, over main
+`4e949f405528fd8087f0623526c62f890c1ce982`, explicitly configures its stdin as
+UTF-8 before reading the request. One new File/SQLite regression first sets
+only the generated Host's decoder to CP1252, sends a Unicode brief and requires
+the rejected artifact to reach task validation. After repairing the artifact,
+revalidation must accept it with the original turn key and exactly one Host
+invocation. The same regression fails with the immutable baseline Host on the
+same CPython 3.13.5/Node 22.22.3 environment, and passes with the correction.
+No transport, production owner, persisted state or protocol vocabulary changes.
+
+On macOS arm64 with Node 22.22.3, CPython 3.11.15 source and a newly installed,
+isolated monolithic wheel each pass the new two provider cases plus all 12
+existing original-task recovery cases. Wheel imports are verified outside the
+checkout before loading the source-owned fixtures; all 1,920 present packaged
+tracked runtime entries match the source bytes. The same 17 source-only
+exclusions remain: canary baseline, host plugin/config, fault-test helper and
+documentation/media. This qualifies the existing File/SQLite
+synthetic Host recovery path, including retained MCP disconnection and lock
+timeout recovery cases, not model adoption, split installation or native
+Windows. The failed original Windows arm remains historical evidence until a
+new exact-head Windows run passes. The independent Frontstage manifest request
+still returns HTTP 504 after its bounded retry.
+
+The original task stays open. Preserve I3 for at least one minor release,
+M1/#8011, full R0/V10/R1, D2/D5/D6/D3, context/model/split-install,
+PostgreSQL host/wheel, whole-path/full marginal-cost/adoption requirements and
+all historical and frozen failures. No cost campaign is repeated or relabeled,
+and this fixture qualification establishes no performance benefit. The report
+loading proposal #8360 retains its independent review and CI gates; the next
+step is exact-head review of this correction and native Windows readback. No
+main merge or installed-host upgrade is included.
+
 ## Appendix B: Decision log
 
 | Date | Decision | Owner / approval | Alternatives | Normative sections changed |
diff --git a/docs/architecture/rfcs/monorepo-distribution-split-v0.zh-CN.md b/docs/architecture/rfcs/monorepo-distribution-split-v0.zh-CN.md
index fac481ef09..60c2ee7943 100644
--- a/docs/architecture/rfcs/monorepo-distribution-split-v0.zh-CN.md
+++ b/docs/architecture/rfcs/monorepo-distribution-split-v0.zh-CN.md
@@ -1993,6 +1993,41 @@ caller 的必需依赖闭包，再选一个完整可回退的加载改动并验
 context／model／split-install、PostgreSQL host／wheel、full-cost／adoption 要求
 继续开放；本轮不合入 main、不升级 host。
 
+### 2026-11-08 — 合成 Host 的 UTF-8 恢复资格
+
+#8360 的 Windows CPython 3.11 CI arm 在六个既有原任务重验证用例中失败。
+合成 Python Host 对 pipe 继承 locale decoder，而原 generic Host transport
+发送 UTF-8 JSON。Disposable File-provider counterprobe 只改变该 Host decoder：
+CP1252 产生 `host_failure`，没有 `task_failure`；UTF-8 到达独立产物 validator，
+在 `task_postcondition` 产生 `validation_failed`，并提供
+`revalidate_cached_result`。源码 macOS arm 独立通过全部12个既有重验证用例。
+这些观察定位了 fixture mismatch，不支持扩大生产 failure classification。
+
+Fixture commit `a4ce613585fdb329ba3600f0ede768864214ed84` 基于 main
+`4e949f405528fd8087f0623526c62f890c1ce982`，在读取请求前显式将 stdin 配为
+UTF-8。新增 File／SQLite regression 先只把生成 Host 的 decoder 设为 CP1252，
+发送 Unicode brief，要求被拒绝的产物到达 task validation。修复产物后，重验证
+必须沿用原 turn key 并接受结果，Host invocation 始终为一次。同一 regression
+在相同 CPython3.13.5／Node22.22.3 环境中对不可变 baseline Host 失败，修正后
+通过。不改变 transport、生产 owner、持久状态或协议词汇。
+
+macOS arm64／Node22.22.3 下，CPython3.11.15 source 与新安装的隔离单体 wheel
+各通过新增两个 provider 用例及全部12个既有原任务恢复用例。先在 checkout 外
+验证 wheel import 归属，再加载 source-owned fixture；1920个实际 packaged
+tracked runtime entry 均与源码字节相同。原17个 source-only exclusion 保留：
+canary baseline、host plugin／config、fault-test helper 和 documentation／media。
+这验收既有 File／SQLite 合成 Host 恢复路径，包括保留的 MCP
+断连及 lock-timeout 恢复用例，不验收模型采纳、split installation 或原生 Windows。
+原失败 Windows arm 保留为历史证据，直到新 exact-head Windows run 通过。
+独立 Frontstage manifest 请求在有界重试后仍为 HTTP504。
+
+原任务保持开放。保留 I3 至少一个 minor release、M1/#8011、完整 R0/V10/R1、
+D2/D5/D6/D3、context/model/split-install、PostgreSQL host/wheel、whole-path／
+full marginal-cost／adoption 验收及全部历史／冻结失败。不重跑或重标签成本
+campaign，本 fixture 资格不证明性能收益。报告按需加载提案 #8360 保留独立
+review／CI gate；下一步为本修正的 exact-head 评审与原生 Windows 读回。不包含
+合入 main 或 installed-host 升级。
+
 ## 附录 B：决策日志
 
 | 日期 | 决策 | 负责人 / 批准 | 备选 | 变更的规范章节 |
diff --git a/tests/test_local_delegation.py b/tests/test_local_delegation.py
index d76b1ae942..e23b5dd6ff 100644
--- a/tests/test_local_delegation.py
+++ b/tests/test_local_delegation.py
@@ -38,6 +38,9 @@
 from loopx.control_plane.quota.turn_envelope import turn_host_lineage
 from loopx.control_plane.collaboration.inbox import acknowledge
 from loopx.control_plane.collaboration.peers import return_result
+# The generic Host protocol sends UTF-8 over a pipe, whose Python 3.11
+# Windows default is a locale codec rather than the console's UTF-8 mode.
+sys.stdin.reconfigure(encoding='utf-8')
 request = json.load(sys.stdin)
 workspace = Path.cwd()
 root = Path(sys.argv[1])
@@ -98,6 +101,35 @@ def brief():
             "return_requirement": "Return the independently checked artifact"}
 
 
+def test_fixture_host_revalidates_utf8_input_under_a_non_utf8_pipe(service):
+    """The fixture must reach task validation with the original UTF-8 identity."""
+    root, runner = service
+    host = root / "fixture-host.py"
+    # Model the Windows Python 3.11 pipe default without changing the parent
+    # transport or requiring a platform-dependent locale on the test runner.
+    host.write_text("import sys; sys.stdin.reconfigure(encoding='cp1252')\n"
+                    + host.read_text(encoding="utf-8"), encoding="utf-8")
+    output = root / "analyst/initial/output.json"
+    saved = output.read_bytes()
+    output.write_text("{}", encoding="utf-8")
+    request = {**brief(), "context": "Read the synthetic résumé: 报告 € → evidence."}
+    runner.start("analysis", "analysis-1", request)
+    rejected = wait(runner)
+    assert rejected["status"] == "rejected", rejected
+    assert "task_failure" in rejected, rejected
+    assert rejected["task_failure"]["resume_mode"] == "revalidate_cached_result"
+    turn_key = rejected["task_failure"]["turn_key"]
+    assert (root / "analyst/initial/host-invocations").read_text() == "1"
+
+    output.write_bytes(saved)
+    runner.revalidate("analysis-1")
+    accepted = wait(runner)
+    assert accepted["status"] == "accepted", accepted
+    assert "task_failure" not in accepted
+    assert json.loads(runner.path("analysis-1").read_text())["turn_key"] == turn_key
+    assert (root / "analyst/initial/host-invocations").read_text() == "1"
+
+
 @pytest.mark.parametrize("provider", ["file", "sqlite"])
 def test_delegation_fixture_isolates_cached_and_child_runtime_routes(tmp_path, monkeypatch, provider):
     """A warmed parent must use the same private Effect server as its CLI."""