diff --git a/README.en.md b/README.en.md
index 46ccc3a..3318a1b 100644
--- a/README.en.md
+++ b/README.en.md
@@ -130,7 +130,7 @@ Yes. Tool calls and web search use DeepSeek's Responses API. Because the text-on
 - **GPT vision.** Borrows the request's ChatGPT OAuth headers (no extra key). Without OAuth headers images pass through untouched. Default model `gpt-5.6-sol`, override with `DSCODEX_VISION_MODEL`.
 - **Key storage, proxy resolution, bridge details, platform differences.** See `AGENTS.md`.
 - **Voice / Pets / plugins / skills / MCP.** All client-side; Voice runs on GPT-Live and is never routed to DeepSeek.
-- **DeepSeek → GPT thread history.** Switching an existing task from DeepSeek back to GPT can currently leave plaintext `reasoning_text` in history and cause a persistent GPT 400 response; see [#17](https://github.com/fish2lab/DSCodex/issues/17). Switching back to DeepSeek or starting a new GPT task remains available.
+- **DeepSeek → GPT thread history.** Switching an existing task between DeepSeek and GPT is safe: before a GPT-bound request, DSCodex strips DeepSeek-only plaintext `reasoning` items (the `reasoning_text` shape with `encrypted_content: null`) so they are never forwarded to ChatGPT. The rollout JSONL is left untouched, and plain GPT traffic without such items still passes through byte-for-byte.
 
 ## Uninstall
 
diff --git a/README.md b/README.md
index f0d68dd..9f65ddc 100644
--- a/README.md
+++ b/README.md
@@ -131,7 +131,7 @@ http://127.0.0.1:10110/<router-token>/v1   ← DSCodex 本地路由
 - **GPT 识图。** 借用请求自带的 OAuth 头，无需额外 key。无 OAuth 时图片原样透传。默认模型 `gpt-5.6-sol`，`DSCODEX_VISION_MODEL` 可换。
 - **Key 存储、代理解析、bridge 细节、平台差异。** 详见 `AGENTS.md`。
 - **Voice / Pets / 插件 / 技能 / MCP。** 均为客户端功能；Voice 由 GPT-Live 驱动，不会路由到 DeepSeek。
-- **DeepSeek → GPT 任务历史。** 同一任务从 DeepSeek 切回 GPT 时，历史中的明文 `reasoning_text` 目前可能导致 GPT 请求返回 400；见 [#17](https://github.com/fish2lab/DSCodex/issues/17)。切回 DeepSeek 或新建 GPT 任务可继续使用。
+- **DeepSeek → GPT 任务历史。** 同一任务在 DeepSeek 与 GPT 之间切换是安全的：发送 GPT 请求前，DSCodex 会剥离 DeepSeek 特有的明文 `reasoning` 项（`reasoning_text` 形状且 `encrypted_content: null`），不会将其转发给 ChatGPT。用户的 rollout JSONL 保持原样，不含此类项的普通 GPT 流量仍按字节透传。
 
 ## 卸载