diff --git a/AGENTS.md b/AGENTS.md
index 77991bc..ff2006e 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -21,3 +21,8 @@ These rules apply to all agent-made changes in this repository.
 
 - Keep changes additive and tightly scoped to the requested feature or bugfix.
 - Do not mix unrelated refactors into feature PRs unless they are required to make the change pass gates.
+
+## Documentation Sync
+
+- `docs/prompt-compatibility.md` is the source-of-truth document for the “API -> pure-text web-chat context” compatibility flow.
+- If a change affects message normalization, tool prompt injection, prompt-visible tool history, file/reference handling, history split, or completion payload assembly, update `docs/prompt-compatibility.md` in the same change.
diff --git a/API.en.md b/API.en.md
index a982b0e..15b491c 100644
--- a/API.en.md
+++ b/API.en.md
@@ -217,9 +217,9 @@ For `chat` / `responses` / `embeddings`, DS2API follows a wide-input/strict-outp
 
 Current built-in default aliases (excerpt):
 
-- OpenAI: `gpt-4o`, `gpt-4.1`, `gpt-4.1-mini`, `gpt-4.1-nano`, `gpt-5`, `gpt-5-mini`, `gpt-5-codex`
-- OpenAI reasoning: `o1`, `o1-mini`, `o3`, `o3-mini`
-- Claude: `claude-sonnet-4-5`, `claude-haiku-4-5`, `claude-opus-4-6` (plus compatibility aliases `claude-3-5-sonnet` / `claude-3-5-haiku` / `claude-3-opus`)
+- OpenAI: `gpt-4o`, `gpt-4.1`, `gpt-5.5`, `gpt-5.4-mini`, `gpt-5.3-codex`
+- OpenAI reasoning: `o1`, `o1-mini`, `o3`, `o4-mini`
+- Claude: `claude-sonnet-4-6`, `claude-haiku-4-5`, `claude-opus-4-6` (plus compatibility aliases `claude-3-5-sonnet` / `claude-3-5-haiku` / `claude-3-opus`)
 - Gemini: `gemini-2.5-pro`, `gemini-2.5-flash`
 
 ### `POST /v1/chat/completions`
@@ -235,7 +235,7 @@ Content-Type: application/json
 
 | Field | Type | Required | Notes |
 | --- | --- | --- | --- |
-| `model` | string | ✅ | DeepSeek native models + common aliases (`gpt-5`, `gpt-5-mini`, `gpt-5-codex`, `o3`, `claude-opus-4-6`, `gemini-2.5-pro`, `gemini-2.5-flash`, etc.) |
+| `model` | string | ✅ | DeepSeek native models + common aliases (`gpt-5.5`, `gpt-5.4-mini`, `gpt-5.3-codex`, `o3`, `claude-opus-4-6`, `gemini-2.5-pro`, `gemini-2.5-flash`, etc.) |
 | `messages` | array | ✅ | OpenAI-style messages |
 | `stream` | boolean | ❌ | Default `false` |
 | `tools` | array | ❌ | Function calling schema |
@@ -442,17 +442,17 @@ No auth required.
 {
   "object": "list",
   "data": [
-    {"id": "claude-sonnet-4-5", "object": "model", "created": 1715635200, "owned_by": "anthropic"},
+    {"id": "claude-sonnet-4-6", "object": "model", "created": 1715635200, "owned_by": "anthropic"},
     {"id": "claude-haiku-4-5", "object": "model", "created": 1715635200, "owned_by": "anthropic"},
     {"id": "claude-opus-4-6", "object": "model", "created": 1715635200, "owned_by": "anthropic"}
   ],
   "first_id": "claude-opus-4-6",
-  "last_id": "claude-instant-1.0",
+  "last_id": "claude-3-haiku-20240307",
   "has_more": false
 }
 ```
 
-> Note: the example is partial; besides the current primary aliases, the real response also includes Claude 4.x snapshots plus historical 3.x / 2.x / 1.x IDs and common aliases.
+> Note: the example is partial; besides the current primary aliases, the real response also includes Claude 4.x snapshots plus historical 3.x IDs and common aliases.
 
 ### `POST /anthropic/v1/messages`
 
@@ -470,7 +470,7 @@ anthropic-version: 2023-06-01
 
 | Field | Type | Required | Notes |
 | --- | --- | --- | --- |
-| `model` | string | ✅ | For example `claude-sonnet-4-5` / `claude-opus-4-6` / `claude-haiku-4-5` (compatible with `claude-3-5-haiku-latest`), plus historical Claude model IDs |
+| `model` | string | ✅ | For example `claude-sonnet-4-6` / `claude-opus-4-6` / `claude-haiku-4-5` (compatible with `claude-3-5-haiku-latest`), plus historical Claude model IDs |
 | `messages` | array | ✅ | Claude-style messages |
 | `max_tokens` | number | ❌ | Auto-filled to `8192` when omitted; not strictly enforced by upstream bridge |
 | `stream` | boolean | ❌ | Default `false` |
@@ -484,7 +484,7 @@ anthropic-version: 2023-06-01
   "id": "msg_1738400000000000000",
   "type": "message",
   "role": "assistant",
-  "model": "claude-sonnet-4-5",
+  "model": "claude-sonnet-4-6",
   "content": [
     {"type": "text", "text": "response"}
   ],
@@ -538,7 +538,7 @@ data: {"type":"message_stop"}
 
 ```json
 {
-  "model": "claude-sonnet-4-5",
+  "model": "claude-sonnet-4-6",
   "messages": [
     {"role": "user", "content": "Hello"}
   ]
@@ -666,16 +666,16 @@ Returns sanitized config, including both `keys` and `api_keys`.
       "token_preview": "abcde..."
     }
   ],
-  "claude_mapping": {
-    "fast": "deepseek-v4-flash",
-    "slow": "deepseek-v4-pro"
+  "model_aliases": {
+    "claude-sonnet-4-6": "deepseek-v4-flash",
+    "claude-opus-4-6": "deepseek-v4-pro"
   }
 }
 ```
 
 ### `POST /admin/config`
 
-Only updates `keys`, `api_keys`, `accounts`, and `claude_mapping`.
+Only updates `keys`, `api_keys`, `accounts`, and `model_aliases`.
 If both `api_keys` and `keys` are sent, the structured `api_keys` entries win so `name` / `remark` metadata is preserved; `keys` remains a legacy fallback.
 
 **Request**:
@@ -690,9 +690,9 @@ If both `api_keys` and `keys` are sent, the structured `api_keys` entries win so
   "accounts": [
     {"email": "user@example.com", "password": "pwd", "token": ""}
   ],
-  "claude_mapping": {
-    "fast": "deepseek-v4-flash",
-    "slow": "deepseek-v4-pro"
+  "model_aliases": {
+    "claude-sonnet-4-6": "deepseek-v4-flash",
+    "claude-opus-4-6": "deepseek-v4-pro"
   }
 }
 ```
@@ -707,7 +707,7 @@ Reads runtime settings and status, including:
 - `compat` (`wide_input_strict_output`, `strip_reference_markers`)
 - `responses` / `embeddings`
 - `auto_delete` (`mode`: `none` / `single` / `all`; legacy `sessions=true` is still treated as `all`)
-- `claude_mapping` / `model_aliases`
+- `model_aliases`
 - `env_backed`, `needs_vercel_sync`
 - `toolcall` policy is fixed to `feature_match + high` and is no longer returned or editable via settings
 
@@ -721,7 +721,6 @@ Hot-updates runtime settings. Supported fields:
 - `responses.store_ttl_seconds`
 - `embeddings.provider`
 - `auto_delete.mode`
-- `claude_mapping`
 - `model_aliases`
 - `toolcall` policy is fixed and is no longer writable through settings
 
@@ -746,7 +745,7 @@ Imports full config with:
 
 The request can send config directly, or wrapped as `{"config": {...}, "mode":"merge"}`.
 Query params `?mode=merge` / `?mode=replace` are also supported.
-Import accepts `keys`, `api_keys`, `accounts`, `claude_mapping` / `claude_model_mapping`, `model_aliases`, `admin`, `runtime`, `responses`, `embeddings`, and `auto_delete`; legacy `toolcall` fields are ignored.
+Import accepts `keys`, `api_keys`, `accounts`, `model_aliases`, `admin`, `runtime`, `responses`, `embeddings`, and `auto_delete`; legacy `toolcall` fields are ignored.
 
 > `compat` fields are managed via `/admin/settings` or the config file; this import endpoint does not update `compat`.
 
@@ -1338,7 +1337,7 @@ curl http://localhost:5001/anthropic/v1/messages \
   -H "Content-Type: application/json" \
   -H "anthropic-version: 2023-06-01" \
   -d '{
-    "model": "claude-sonnet-4-5",
+    "model": "claude-sonnet-4-6",
     "max_tokens": 1024,
     "messages": [{"role": "user", "content": "Hello"}]
   }'
diff --git a/API.md b/API.md
index 0fa81d3..e309eff 100644
--- a/API.md
+++ b/API.md
@@ -217,11 +217,13 @@ Gemini 兼容客户端还可以使用 `x-goog-api-key`、`?key=` 或 `?api_key=`
 
 当前内置默认 alias（节选）：
 
-- OpenAI：`gpt-4o`、`gpt-4.1`、`gpt-4.1-mini`、`gpt-4.1-nano`、`gpt-5`、`gpt-5-mini`、`gpt-5-codex`
+- OpenAI：`gpt-4o`、`gpt-4.1`、`gpt-4.1-mini`、`gpt-4.1-nano`、`gpt-5`、`gpt-5.4`、`gpt-5.5`、`gpt-5-mini`、`gpt-5.4-mini`、`gpt-5.4-nano`、`gpt-5.5-pro`、`gpt-5-codex`、`gpt-5.3-codex`
 - OpenAI Reasoning：`o1`、`o1-mini`、`o3`、`o3-mini`
-- Claude：`claude-sonnet-4-5`、`claude-haiku-4-5`、`claude-opus-4-6`（及 `claude-3-5-sonnet` / `claude-3-5-haiku` / `claude-3-opus` 兼容别名）
+- Claude：`claude-sonnet-4-6`、`claude-haiku-4-5`、`claude-opus-4-6`（及 `claude-sonnet-4-5` / `claude-3-5-sonnet` / `claude-3-5-haiku` / `claude-3-opus` 兼容别名）
 - Gemini：`gemini-2.5-pro`、`gemini-2.5-flash`
 
+> 截至 2026-04-26：OpenAI 开发者模型页当前推荐 `gpt-5.5` 作为旗舰 API 模型；ChatGPT Help Center 当前主打 `GPT-5.3 Instant / GPT-5.5 Thinking / GPT-5.5 Pro`；Anthropic 官方模型页当前主推 `claude-opus-4-6`、`claude-sonnet-4-6`、`claude-haiku-4-5`。
+
 ### `POST /v1/chat/completions`
 
 **请求头**：
@@ -235,7 +237,7 @@ Content-Type: application/json
 
 | 字段 | 类型 | 必填 | 说明 |
 | --- | --- | --- | --- |
-| `model` | string | ✅ | 支持 DeepSeek 原生模型 + 常见 alias（如 `gpt-5`、`gpt-5-mini`、`gpt-5-codex`、`o3`、`claude-opus-4-6`、`gemini-2.5-pro`、`gemini-2.5-flash` 等） |
+| `model` | string | ✅ | 支持 DeepSeek 原生模型 + 常见 alias（如 `gpt-5.5`、`gpt-5.4-mini`、`gpt-5.3-codex`、`o3`、`claude-opus-4-6`、`claude-sonnet-4-6`、`gemini-2.5-pro`、`gemini-2.5-flash` 等） |
 | `messages` | array | ✅ | OpenAI 风格消息数组 |
 | `stream` | boolean | ❌ | 默认 `false` |
 | `tools` | array | ❌ | Function Calling 定义 |
@@ -443,17 +445,17 @@ data: [DONE]
 {
   "object": "list",
   "data": [
-    {"id": "claude-sonnet-4-5", "object": "model", "created": 1715635200, "owned_by": "anthropic"},
+    {"id": "claude-sonnet-4-6", "object": "model", "created": 1715635200, "owned_by": "anthropic"},
     {"id": "claude-haiku-4-5", "object": "model", "created": 1715635200, "owned_by": "anthropic"},
     {"id": "claude-opus-4-6", "object": "model", "created": 1715635200, "owned_by": "anthropic"}
   ],
   "first_id": "claude-opus-4-6",
-  "last_id": "claude-instant-1.0",
+  "last_id": "claude-3-haiku-20240307",
   "has_more": false
 }
 ```
 
-> 说明：示例仅展示部分模型；实际返回除当前主别名外，还包含 Claude 4.x snapshots，以及 3.x / 2.x / 1.x 历史模型 ID 与常见别名。
+> 说明：示例仅展示部分模型；实际返回除当前主别名外，还包含 Claude 4.x snapshots，以及 3.x 历史模型 ID 与常见别名。
 
 ### `POST /anthropic/v1/messages`
 
@@ -471,7 +473,7 @@ anthropic-version: 2023-06-01
 
 | 字段 | 类型 | 必填 | 说明 |
 | --- | --- | --- | --- |
-| `model` | string | ✅ | 例如 `claude-sonnet-4-5` / `claude-opus-4-6` / `claude-haiku-4-5`（兼容 `claude-3-5-haiku-latest`），并支持历史 Claude 模型 ID |
+| `model` | string | ✅ | 例如 `claude-sonnet-4-6` / `claude-opus-4-6` / `claude-haiku-4-5`（兼容 `claude-sonnet-4-5`、`claude-3-5-haiku-latest`），并支持历史 Claude 模型 ID |
 | `messages` | array | ✅ | Claude 风格消息数组 |
 | `max_tokens` | number | ❌ | 缺省自动补 `8192`；当前实现不会硬性截断上游输出 |
 | `stream` | boolean | ❌ | 默认 `false` |
@@ -485,7 +487,7 @@ anthropic-version: 2023-06-01
   "id": "msg_1738400000000000000",
   "type": "message",
   "role": "assistant",
-  "model": "claude-sonnet-4-5",
+  "model": "claude-sonnet-4-6",
   "content": [
     {"type": "text", "text": "回复内容"}
   ],
@@ -539,7 +541,7 @@ data: {"type":"message_stop"}
 
 ```json
 {
-  "model": "claude-sonnet-4-5",
+  "model": "claude-sonnet-4-6",
   "messages": [
     {"role": "user", "content": "你好"}
   ]
@@ -667,16 +669,16 @@ data: {"type":"message_stop"}
       "token_preview": "abcde..."
     }
   ],
-  "claude_mapping": {
-    "fast": "deepseek-v4-flash",
-    "slow": "deepseek-v4-pro"
+  "model_aliases": {
+    "claude-sonnet-4-6": "deepseek-v4-flash",
+    "claude-opus-4-6": "deepseek-v4-pro"
   }
 }
 ```
 
 ### `POST /admin/config`
 
-只更新 `keys`、`api_keys`、`accounts`、`claude_mapping`。
+只更新 `keys`、`api_keys`、`accounts`、`model_aliases`。
 如果同时发送 `api_keys` 与 `keys`，优先保留 `api_keys` 中的结构化 `name` / `remark`；`keys` 仅作为旧格式兼容回退。
 
 **请求**：
@@ -691,9 +693,9 @@ data: {"type":"message_stop"}
   "accounts": [
     {"email": "user@example.com", "password": "pwd", "token": ""}
   ],
-  "claude_mapping": {
-    "fast": "deepseek-v4-flash",
-    "slow": "deepseek-v4-pro"
+  "model_aliases": {
+    "claude-sonnet-4-6": "deepseek-v4-flash",
+    "claude-opus-4-6": "deepseek-v4-pro"
   }
 }
 ```
@@ -708,7 +710,7 @@ data: {"type":"message_stop"}
 - `compat`（`wide_input_strict_output`、`strip_reference_markers`）
 - `responses` / `embeddings`
 - `auto_delete`（`mode`：`none` / `single` / `all`；旧配置 `sessions=true` 仍按 `all` 处理）
-- `claude_mapping` / `model_aliases`
+- `model_aliases`
 - `env_backed`、`needs_vercel_sync`
 - `toolcall` 策略已固定为 `feature_match + high`，不再通过 settings 返回或修改
 
@@ -722,7 +724,6 @@ data: {"type":"message_stop"}
 - `responses.store_ttl_seconds`
 - `embeddings.provider`
 - `auto_delete.mode`
-- `claude_mapping`
 - `model_aliases`
 - `toolcall` 策略已固定，不再作为可写入字段
 
@@ -747,7 +748,7 @@ data: {"type":"message_stop"}
 
 请求可直接传配置对象，或使用 `{"config": {...}, "mode":"merge"}` 包裹格式。
 也支持在查询参数里传 `?mode=merge` / `?mode=replace`。
-导入时会接受 `keys`、`api_keys`、`accounts`、`claude_mapping` / `claude_model_mapping`、`model_aliases`、`admin`、`runtime`、`responses`、`embeddings`、`auto_delete` 等字段；`toolcall` 相关字段会被忽略。
+导入时会接受 `keys`、`api_keys`、`accounts`、`model_aliases`、`admin`、`runtime`、`responses`、`embeddings`、`auto_delete` 等字段；`toolcall` 相关字段会被忽略。
 
 > `compat` 相关字段请通过 `/admin/settings` 或配置文件管理；该导入接口不会更新 `compat`。
 
@@ -1242,7 +1243,7 @@ curl http://localhost:5001/v1/responses \
   -H "Authorization: Bearer your-api-key" \
   -H "Content-Type: application/json" \
   -d '{
-    "model": "gpt-5-codex",
+    "model": "gpt-5.3-codex",
     "input": "写一个 golang 的 hello world",
     "stream": true
   }'
@@ -1341,7 +1342,7 @@ curl http://localhost:5001/anthropic/v1/messages \
   -H "Content-Type: application/json" \
   -H "anthropic-version: 2023-06-01" \
   -d '{
-    "model": "claude-sonnet-4-5",
+    "model": "claude-sonnet-4-6",
     "max_tokens": 1024,
     "messages": [{"role": "user", "content": "你好"}]
   }'
diff --git a/README.MD b/README.MD
index c8686bc..2e78110 100644
--- a/README.MD
+++ b/README.MD
@@ -122,18 +122,20 @@ flowchart LR
 | vision | `deepseek-v4-vision` | 默认开启，可由请求参数控制 | ❌ |
 | vision | `deepseek-v4-vision-search` | 默认开启，可由请求参数控制 | ✅ |
 
-除原生模型外，也支持常见 alias 输入（如 `gpt-5`、`gpt-5-mini`、`gpt-5-codex`、`gpt-4.1`、`o3`、`claude-opus-4-6`、`claude-sonnet-4-5`、`gemini-2.5-pro`、`gemini-2.5-flash` 等），但 `/v1/models` 返回的是规范化后的 DeepSeek 原生模型 ID。
+除原生模型外，也支持常见 alias 输入（如 `gpt-5.5`、`gpt-5.4`、`gpt-5.4-mini`、`gpt-5.3-codex`、`gpt-4.1`、`o3`、`claude-opus-4-6`、`claude-sonnet-4-6`、`gemini-2.5-pro`、`gemini-2.5-flash` 等），但 `/v1/models` 返回的是规范化后的 DeepSeek 原生模型 ID。
 
 ### Claude 接口（`GET /anthropic/v1/models`）
 
 | 当前常用模型 | 默认映射 |
 | --- | --- |
-| `claude-sonnet-4-5` | `deepseek-v4-flash` |
+| `claude-sonnet-4-6` | `deepseek-v4-flash` |
 | `claude-haiku-4-5`（兼容 `claude-3-5-haiku-latest`） | `deepseek-v4-flash` |
 | `claude-opus-4-6` | `deepseek-v4-pro` |
 
-可通过配置中的 `claude_mapping` 或 `claude_model_mapping` 覆盖映射关系。
-`/anthropic/v1/models` 除上述当前主别名外，还会返回 Claude 4.x snapshots，以及 3.x / 2.x / 1.x 历史模型 ID 与常见 alias，便于旧客户端直接兼容。
+可通过配置中的 `model_aliases` 覆盖映射关系。
+`/anthropic/v1/models` 除上述当前主别名外，还会返回 Claude 4.x snapshots，以及 3.x 历史模型 ID 与常见 alias，便于旧客户端直接兼容。
+
+> 截至 2026-04-26：Anthropic 官方模型页当前主推 `claude-opus-4-6`、`claude-sonnet-4-6`、`claude-haiku-4-5`；OpenAI 官方开发者模型页当前推荐从 `gpt-5.5` 开始，ChatGPT Help Center 当前主打 `GPT-5.3 Instant / GPT-5.5 Thinking / GPT-5.5 Pro`。本文档中的 alias 示例按“兼容客户端会传来的最新官方模型 ID”维护。
 
 #### Claude Code 接入避坑（实测）
 
@@ -289,9 +291,9 @@ go run ./cmd/ds2api
   ],
   "model_aliases": {
     "gpt-4o": "deepseek-v4-flash",
-    "gpt-5": "deepseek-v4-flash",
-    "gpt-5-mini": "deepseek-v4-flash",
-    "gpt-5-codex": "deepseek-v4-pro",
+    "gpt-5.5": "deepseek-v4-flash",
+    "gpt-5.4-mini": "deepseek-v4-flash",
+    "gpt-5.3-codex": "deepseek-v4-pro",
     "o3": "deepseek-v4-pro",
     "claude-opus-4-6": "deepseek-v4-pro",
     "gemini-2.5-flash": "deepseek-v4-flash"
@@ -306,10 +308,6 @@ go run ./cmd/ds2api
   "embeddings": {
     "provider": "deterministic"
   },
-  "claude_mapping": {
-    "fast": "deepseek-v4-flash",
-    "slow": "deepseek-v4-pro"
-  },
   "admin": {
     "jwt_expire_hours": 24
   },
@@ -335,7 +333,7 @@ go run ./cmd/ds2api
 - `toolcall`：旧字段，当前实现已固定为特征匹配 + 高置信早发；即使保留在配置里也会被忽略
 - `responses.store_ttl_seconds`：`/v1/responses/{id}` 的内存缓存 TTL
 - `embeddings.provider`：embedding 提供方（当前内置 `deterministic/mock/builtin`）
-- `claude_mapping`：字典中 `fast`/`slow` 后缀映射到对应 DeepSeek 模型（兼容读取 `claude_model_mapping`）
+- `model_aliases`：全局统一模型映射表，OpenAI / Claude / Gemini 共用；项目内只维护这一套映射入口
 - `admin`：管理后台设置（JWT 过期时间、密码哈希等），可通过 Admin Settings API 热更新
 - `runtime`：运行时参数（并发限制、队列大小、托管账号 token 刷新间隔），可通过 Admin Settings API 热更新；`account_max_queue=0`/`global_max_inflight=0` 表示按推荐值自动计算，`token_refresh_interval_hours=6` 为默认强制重登间隔
 - `auto_delete.mode`：请求结束后如何清理 DeepSeek 远端聊天记录，支持 `none`（默认，不删除）、`single`（仅删除当前会话）、`all`（清空全部会话）；旧配置里的 `auto_delete.sessions=true` 仍会被视为 `all`
diff --git a/README.en.md b/README.en.md
index 91c0bfe..f2e77cb 100644
--- a/README.en.md
+++ b/README.en.md
@@ -120,18 +120,18 @@ For the full module-by-module architecture and directory responsibilities, see [
 | vision | `deepseek-v4-vision` | enabled by default, request-controlled | ❌ |
 | vision | `deepseek-v4-vision-search` | enabled by default, request-controlled | ✅ |
 
-Besides native IDs, DS2API also accepts common aliases as input (for example `gpt-5`, `gpt-5-mini`, `gpt-5-codex`, `gpt-4.1`, `o3`, `claude-opus-4-6`, `claude-sonnet-4-5`, `gemini-2.5-pro`, `gemini-2.5-flash`), but `/v1/models` returns normalized DeepSeek native model IDs.
+Besides native IDs, DS2API also accepts common aliases as input (for example `gpt-5.5`, `gpt-5.4-mini`, `gpt-5.3-codex`, `gpt-4.1`, `o3`, `claude-opus-4-6`, `claude-sonnet-4-6`, `gemini-2.5-pro`, `gemini-2.5-flash`), but `/v1/models` returns normalized DeepSeek native model IDs.
 
 ### Claude Endpoint (`GET /anthropic/v1/models`)
 
 | Current common model | Default Mapping |
 | --- | --- |
-| `claude-sonnet-4-5` | `deepseek-v4-flash` |
+| `claude-sonnet-4-6` | `deepseek-v4-flash` |
 | `claude-haiku-4-5` (compatible with `claude-3-5-haiku-latest`) | `deepseek-v4-flash` |
 | `claude-opus-4-6` | `deepseek-v4-pro` |
 
-Override mapping via `claude_mapping` or `claude_model_mapping` in config.
-Besides the current primary aliases above, `/anthropic/v1/models` also returns Claude 4.x snapshots plus historical 3.x / 2.x / 1.x IDs and common aliases for legacy client compatibility.
+Override mapping via the global `model_aliases` config.
+Besides the current primary aliases above, `/anthropic/v1/models` also returns Claude 4.x snapshots plus historical 3.x IDs and common aliases for legacy client compatibility.
 
 #### Claude Code integration pitfalls (validated)
 
@@ -295,10 +295,6 @@ The server actually binds to `0.0.0.0:5001`, so devices on the same LAN can usua
   "embeddings": {
     "provider": "deterministic"
   },
-  "claude_mapping": {
-    "fast": "deepseek-v4-flash",
-    "slow": "deepseek-v4-pro"
-  },
   "admin": {
     "jwt_expire_hours": 24
   },
@@ -317,13 +313,12 @@ The server actually binds to `0.0.0.0:5001`, so devices on the same LAN can usua
 - `keys`: API access keys; clients authenticate via `Authorization: Bearer <key>`
 - `accounts`: DeepSeek account list, supports `email` or `mobile` login
 - `token`: Even if set in `config.json`, it is cleared during load (DS2API does not read persisted tokens from config); runtime tokens are maintained/refreshed in memory only
-- `model_aliases`: Map common model names (GPT/Codex/Claude) to DeepSeek models
+- `model_aliases`: Single global alias map shared by OpenAI / Claude / Gemini model names
 - `compat.wide_input_strict_output`: Keep `true` (current default policy)
 - `compat.strip_reference_markers`: Keep `true`; it strips reference markers from visible output
 - `toolcall`: Legacy field; the current behavior is fixed to feature matching + high-confidence early emit, and any config value is ignored
 - `responses.store_ttl_seconds`: In-memory TTL for `/v1/responses/{id}`
 - `embeddings.provider`: Embeddings provider (`deterministic/mock/builtin` built-in)
-- `claude_mapping`: Maps `fast`/`slow` suffixes to corresponding DeepSeek models (still compatible with `claude_model_mapping`)
 - `admin`: Admin panel settings (JWT expiry, password hash, etc.), hot-reloadable via Admin Settings API
 - `runtime`: Runtime parameters (concurrency limits, queue sizes, managed token refresh interval), hot-reloadable via Admin Settings API; `account_max_queue=0`/`global_max_inflight=0` means auto-calculate from recommended values, `token_refresh_interval_hours=6` is the default forced re-login interval
 - `auto_delete.mode`: How to clean up DeepSeek remote chat records after each request completes. Supported values: `none` (default, no deletion), `single` (delete only the current session), `all` (delete all sessions); legacy `auto_delete.sessions=true` is still treated as `all`
diff --git a/config.example.json b/config.example.json
index ce3d902..f93a2c3 100644
--- a/config.example.json
+++ b/config.example.json
@@ -39,7 +39,8 @@
   ],
   "model_aliases": {
     "gpt-4o": "deepseek-v4-flash",
-    "gpt-5-codex": "deepseek-v4-pro",
+    "gpt-5.5": "deepseek-v4-flash",
+    "gpt-5.3-codex": "deepseek-v4-pro",
     "o3": "deepseek-v4-pro"
   },
   "compat": {
@@ -56,10 +57,6 @@
   "embeddings": {
     "provider": "deterministic"
   },
-  "claude_mapping": {
-    "fast": "deepseek-v4-flash",
-    "slow": "deepseek-v4-pro"
-  },
   "admin": {
     "jwt_expire_hours": 24
   },
diff --git a/docs/README.md b/docs/README.md
index f8b5d8d..837fc87 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -15,6 +15,7 @@
 
 ### 专题文档
 
+- [API -> 网页对话纯文本兼容主链路说明](./prompt-compatibility.md)
 - [Tool Calling 统一语义](./toolcall-semantics.md)
 - [DeepSeek SSE 行为结构说明（逆向观察）](./DeepSeekSSE行为结构说明-2026-04-05.md)
 
@@ -23,6 +24,7 @@
 - `README.MD` / `README.en.md`：面向首次接触用户，保留“是什么 + 怎么快速跑起来”。
 - `docs/ARCHITECTURE*.md`：面向开发者，集中维护项目结构、模块职责与调用链。
 - `API*.md`：面向客户端接入者，聚焦接口行为、鉴权和示例。
+- `docs/prompt-compatibility.md`：面向维护者，集中维护“API -> 网页对话纯文本上下文”的统一兼容语义；相关行为修改时必须同步更新。
 - 其他 `docs/*.md`：主题化说明，避免在多个文档重复粘贴同一段内容。
 
 ---
@@ -42,6 +44,7 @@ Recommended reading order:
 
 ### Topical docs
 
+- [API -> pure-text web-chat compatibility pipeline](./prompt-compatibility.md)
 - [Tool-calling unified semantics](./toolcall-semantics.md)
 - [DeepSeek SSE behavior notes (reverse-engineered)](./DeepSeekSSE行为结构说明-2026-04-05.md)
 
@@ -50,4 +53,5 @@ Recommended reading order:
 - `README.MD` / `README.en.md`: onboarding-oriented (“what + quick start”).
 - `docs/ARCHITECTURE*.md`: developer-oriented source of truth for module boundaries and execution flow.
 - `API*.md`: integration-oriented behavior/contracts.
+- `docs/prompt-compatibility.md`: maintainer-oriented source of truth for the “API -> pure-text web-chat context” compatibility flow; update it whenever related behavior changes.
 - Other `docs/*.md`: focused topics, avoid copy-pasting the same section into multiple files.
diff --git a/docs/prompt-compatibility.md b/docs/prompt-compatibility.md
new file mode 100644
index 0000000..1b03ca0
--- /dev/null
+++ b/docs/prompt-compatibility.md
@@ -0,0 +1,391 @@
+# API -> 网页对话纯文本兼容主链路说明
+
+文档导航：[总览](../README.MD) / [架构说明](./ARCHITECTURE.md) / [接口文档](../API.md) / [测试指南](./TESTING.md)
+
+> 本文档是 DS2API“把 OpenAI / Claude / Gemini 风格 API 请求兼容成 DeepSeek 网页对话纯文本上下文”的专项说明。
+> 这是项目最重要的兼容产物之一。凡是修改消息标准化、tool prompt 注入、tool history 保留、文件引用、history split、下游 completion payload 组装等行为，都必须同步更新本文档。
+
+## 1. 核心结论
+
+DS2API 当前的核心思路，不是把客户端传来的 `messages`、`tools`、`attachments` 原样转发给下游。
+
+而是把这些高层 API 语义，统一压缩成 DeepSeek 网页对话更容易理解的三类输入：
+
+1. `prompt`
+   一个单字符串，里面带有角色标记、system 指令、历史消息、assistant reasoning 标签、历史 tool call XML 等。
+2. `ref_file_ids`
+   一个文件引用数组，承载附件、inline 上传文件，以及必要时被拆出去的历史文件。
+3. 控制位
+   例如 `thinking_enabled`、`search_enabled`、部分 passthrough 参数。
+
+也就是说，项目最重要的兼容动作，是把“结构化 API 会话”翻译成“网页对话纯文本上下文 + 文件引用”。
+
+## 2. 为什么这是核心产物
+
+因为对下游来说，真正稳定的输入面不是 OpenAI/Claude/Gemini 的原生 schema，而是：
+
+- 一段连续的对话 prompt
+- 一组可引用文件
+- 少量开关位
+
+这也是为什么很多表面上看像“协议兼容”的代码，最终都会收敛到同一类逻辑：
+
+- 先把不同协议的消息统一成内部消息序列
+- 再把工具声明改写成 system prompt 文本
+- 再把历史 tool call / tool result 改写成 prompt 可见内容
+- 最后输出成 DeepSeek completion payload
+
+## 3. 统一心智模型
+
+当前主链路可以这样理解：
+
+```text
+客户端请求
+  -> 协议适配层（OpenAI / Claude / Gemini）
+  -> 统一消息标准化
+  -> tool prompt 注入
+  -> DeepSeek 风格 prompt 拼装
+  -> 文件收集 / inline 上传 / history split
+  -> completion payload
+  -> 下游网页对话接口
+```
+
+对应的关键代码入口：
+
+- OpenAI Chat / Responses：
+  [internal/adapter/openai/standard_request.go](../internal/adapter/openai/standard_request.go)
+- OpenAI prompt 组装：
+  [internal/adapter/openai/prompt_build.go](../internal/adapter/openai/prompt_build.go)
+- OpenAI 消息标准化：
+  [internal/adapter/openai/message_normalize.go](../internal/adapter/openai/message_normalize.go)
+- Claude 标准化：
+  [internal/adapter/claude/standard_request.go](../internal/adapter/claude/standard_request.go)
+- Claude 消息与 tool_use/tool_result 归一：
+  [internal/adapter/claude/handler_utils.go](../internal/adapter/claude/handler_utils.go)
+- Gemini 复用 OpenAI prompt builder：
+  [internal/adapter/gemini/convert_request.go](../internal/adapter/gemini/convert_request.go)
+- DeepSeek prompt 角色标记拼装：
+  [internal/prompt/messages.go](../internal/prompt/messages.go)
+- prompt 可见 tool history XML：
+  [internal/prompt/tool_calls.go](../internal/prompt/tool_calls.go)
+- completion payload：
+  [internal/util/standard_request.go](../internal/util/standard_request.go)
+
+## 4. 下游真正收到的东西
+
+在“完成标准化后”，下游 completion payload 的核心形态是：
+
+```json
+{
+  "chat_session_id": "session-id",
+  "model_type": "default",
+  "parent_message_id": null,
+  "prompt": "<｜begin▁of▁sentence｜>...",
+  "ref_file_ids": [
+    "file-history",
+    "file-systemprompt",
+    "file-other-attachment"
+  ],
+  "thinking_enabled": true,
+  "search_enabled": false
+}
+```
+
+重点是：
+
+- `prompt` 才是对话上下文主载体。
+- `ref_file_ids` 只承载文件引用，不承载普通文本消息。
+- `tools` 不会作为“原生工具 schema”直接下发给下游，而是被改写进 `prompt`。
+
+## 5. prompt 是怎么拼出来的
+
+### 5.1 角色标记
+
+最终 prompt 使用 DeepSeek 风格角色标记：
+
+- `<｜begin▁of▁sentence｜>`
+- `<｜System｜>`
+- `<｜User｜>`
+- `<｜Assistant｜>`
+- `<｜Tool｜>`
+- `<｜end▁of▁instructions｜>`
+- `<｜end▁of▁sentence｜>`
+- `<｜end▁of▁toolresults｜>`
+
+实现位置：
+[internal/prompt/messages.go](../internal/prompt/messages.go)
+
+### 5.2 thinking continuity 说明
+
+如果启用了 thinking，会在最前面额外插入一个 system block，提醒模型：
+
+- 继续既有会话，不要重开
+- earlier messages 是 binding context
+- 不要把最终回答只留在 reasoning 里
+
+这部分不是客户端原始消息，而是兼容层主动补进去的连续性契约。
+
+### 5.3 相邻同角色消息会合并
+
+在最终 `MessagesPrepareWithThinking` 中，相邻同 role 的消息会被合并成一个块，中间插入空行。
+
+这意味着：
+
+- prompt 中看到的是“合并后的 role block”
+- 不是客户端传来的逐条 message 原样排列
+
+## 6. tools 为什么是“文本注入”，不是原生下发
+
+当前项目把工具能力视为“prompt 约束的一部分”。
+
+具体做法：
+
+1. 把每个 tool 的名称、描述、参数 schema 序列化成文本。
+2. 拼成 `You have access to these tools:` 大段说明。
+3. 再附上统一的 XML tool call 格式约束。
+4. 把这整段内容并入 system prompt。
+
+OpenAI 路径实现：
+[internal/adapter/openai/handler_toolcall_format.go](../internal/adapter/openai/handler_toolcall_format.go)
+
+Claude 路径实现：
+[internal/adapter/claude/handler_utils.go](../internal/adapter/claude/handler_utils.go)
+
+统一工具调用格式模板：
+[internal/toolcall/tool_prompt.go](../internal/toolcall/tool_prompt.go)
+
+这也是项目“网页对话纯文本兼容”的关键设计：
+
+- tools 对下游来说，本质上是 prompt 内规则
+- 不是 native tool schema transport
+
+## 7. assistant 的 tool_calls / reasoning 如何保留
+
+### 7.1 reasoning 保留方式
+
+assistant 的 reasoning 会变成一个显式标签块：
+
+```text
+[reasoning_content]
+...
+[/reasoning_content]
+```
+
+然后再接可见回答正文。
+
+### 7.2 历史 tool_calls 保留方式
+
+assistant 历史 `tool_calls` 不会保留成 OpenAI 原生 JSON，而会转成 prompt 可见的 XML：
+
+```xml
+<tools>
+  <tool_call>
+    <tool_name>read_file</tool_name>
+    <param>
+      <path><![CDATA[src/main.go]]></path>
+    </param>
+  </tool_call>
+</tools>
+```
+
+这件事很重要，因为它决定了：
+
+- 历史工具调用在 prompt 中是“可见文本历史”
+- 不是“隐藏结构化元数据”
+
+实现位置：
+[internal/prompt/tool_calls.go](../internal/prompt/tool_calls.go)
+
+### 7.3 tool result 保留方式
+
+tool / function role 的结果会作为 `<｜Tool｜>...<｜end▁of▁toolresults｜>` 进入 prompt。
+
+如果 tool content 为空，当前会补成字符串 `"null"`，避免整个 tool turn 丢失。
+
+## 8. files、附件、systemprompt 文件的实际语义
+
+这里要明确区分两类东西：
+
+1. 文本型 system prompt
+   例如 OpenAI `developer` / `system` / Responses `instructions` / Claude top-level `system`
+   这类会进入 `prompt`。
+2. 文件型 systemprompt
+   例如通过附件、`input_file`、base64、data URL 上传的文件
+   这类不会直接内联进 `prompt`，而是进入 `ref_file_ids`。
+
+OpenAI 文件相关实现：
+
+- inline/base64/data URL 上传：
+  [internal/adapter/openai/file_inline_upload.go](../internal/adapter/openai/file_inline_upload.go)
+- 文件 ID 收集：
+  [internal/adapter/openai/file_refs.go](../internal/adapter/openai/file_refs.go)
+
+结论：
+
+- “systemprompt 文字”在 prompt 里
+- “systemprompt 文件”通常只在 `ref_file_ids` 里
+
+除非调用方自己把文件内容展开后再塞进 system/developer 文本，否则文件内容不会自动出现在 prompt 正文。
+
+## 9. 多轮历史为什么不会一直完整内联在 prompt
+
+默认情况下，history split 是开启的，且默认从第 2 个 user turn 起就可能触发。
+
+相关实现：
+
+- 配置访问器：
+  [internal/config/store_accessors.go](../internal/config/store_accessors.go)
+- 历史拆分：
+  [internal/adapter/openai/history_split.go](../internal/adapter/openai/history_split.go)
+
+触发后行为：
+
+1. 旧历史消息被切出去。
+2. 旧历史会被重新序列化成一个文本文件。
+3. 文件名固定是 `IGNORE`。
+4. 该文件上传后，其 `file_id` 会排在 `ref_file_ids` 最前面。
+5. live prompt 只保留：
+   - system / developer
+   - 最新 user turn 起的上下文
+
+历史文件内容不是普通自由文本，而是用同一套角色标记再次序列化出的 transcript：
+
+```text
+[file content end]
+
+<｜begin▁of▁sentence｜><｜User｜>...<｜Assistant｜>...<｜Tool｜>...
+
+[file name]: IGNORE
+[file content begin]
+```
+
+所以“完整上下文”在当前实现里，其实通常分散在两处：
+
+- `prompt` 里的 live context
+- `ref_file_ids` 指向的 history transcript file
+
+## 10. 各协议入口的差异
+
+### 10.1 OpenAI Chat / Responses
+
+特点：
+
+- `developer` 会映射到 `system`
+- Responses `instructions` 会 prepend 为 system message
+- `tools` 会注入 system prompt
+- `attachments` / `input_file` / inline 文件会进入 `ref_file_ids`
+- history split 主要在这条链路里生效
+
+### 10.2 Claude Messages
+
+特点：
+
+- top-level `system` 优先作为系统提示
+- `tool_use` / `tool_result` 会被转换成统一的 assistant/tool 历史语义
+- `tools` 同样会被并进 system prompt
+- 当前代码里没有像 OpenAI 那样完整的 `ref_file_ids` 附件链路
+
+### 10.3 Gemini
+
+特点：
+
+- `systemInstruction`、`contents.parts`、`functionCall`、`functionResponse` 会先归一
+- tools 会转成 OpenAI 风格 function schema
+- prompt 构建复用 OpenAI 的 `BuildPromptForAdapter`
+
+也就是说，Gemini 在“最终 prompt 语义”上，尽量和 OpenAI 保持一致。
+
+## 11. 一份贴近真实的最终上下文示意
+
+假设用户发来一个多轮请求：
+
+- 有 system/developer 文本
+- 有 tools
+- 有一个文件型 systemprompt 附件
+- 有历史 assistant tool call / tool result
+- history split 已触发
+
+那么最终上下文更接近：
+
+```json
+{
+  "prompt": "<｜begin▁of▁sentence｜><｜System｜>continuity instructions...\\n\\n原 system / developer\\n\\nYou have access to these tools: ...<｜end▁of▁instructions｜><｜User｜>最新问题<｜Assistant｜>",
+  "ref_file_ids": [
+    "file-history-ignore",
+    "file-systemprompt",
+    "file-other-attachment"
+  ],
+  "thinking_enabled": true,
+  "search_enabled": false
+}
+```
+
+这正是“API 转网页对话纯文本”的核心成果：
+
+- 大部分结构化语义被压进 `prompt`
+- 文件保持文件
+- 历史必要时拆文件
+
+## 12. 修改时必须同步本文档的场景
+
+只要触碰以下任一类行为，就必须在同一提交或同一 PR 中更新本文档：
+
+- 角色映射变更
+- system / developer / instructions 合并规则变更
+- assistant reasoning 保留格式变更
+- assistant 历史 `tool_calls` 的 XML 呈现方式变更
+- tool result 注入方式变更
+- tool prompt 模板或 tool_choice 约束变更
+- inline 文件上传 / 文件引用收集规则变更
+- history split 触发条件、上传格式、`IGNORE` 包装格式变更
+- completion payload 字段语义变更
+- Claude / Gemini 对这套统一语义的复用关系变更
+
+优先检查这些文件：
+
+- `internal/adapter/openai/standard_request.go`
+- `internal/adapter/openai/prompt_build.go`
+- `internal/adapter/openai/message_normalize.go`
+- `internal/adapter/openai/handler_toolcall_format.go`
+- `internal/adapter/openai/file_inline_upload.go`
+- `internal/adapter/openai/file_refs.go`
+- `internal/adapter/openai/history_split.go`
+- `internal/adapter/openai/responses_input_normalize.go`
+- `internal/adapter/claude/standard_request.go`
+- `internal/adapter/claude/handler_utils.go`
+- `internal/adapter/gemini/convert_request.go`
+- `internal/adapter/gemini/convert_messages.go`
+- `internal/adapter/gemini/convert_tools.go`
+- `internal/prompt/messages.go`
+- `internal/prompt/tool_calls.go`
+- `internal/util/standard_request.go`
+
+## 13. 建议的最小验证
+
+改动这条链路后，至少补齐或检查这些测试：
+
+- `go test ./internal/prompt/...`
+- `go test ./internal/adapter/openai/...`
+- `go test ./internal/adapter/claude/...`
+- `go test ./internal/adapter/gemini/...`
+- `go test ./internal/util/...`
+
+如果改的是 tool call 相关兼容语义，还应同时检查：
+
+- `go test ./internal/toolcall/...`
+- `node --test tests/node/stream-tool-sieve.test.js`
+
+## 14. 文档同步约定
+
+本文档是这条兼容链路的专项说明。
+
+如果外部接口行为也变了，还应同步检查：
+
+- [API.md](../API.md)
+- [API.en.md](../API.en.md)
+- [docs/toolcall-semantics.md](./toolcall-semantics.md)
+
+原则是：
+
+- 内部主链路变化，至少更新本文档
+- 外部可见契约变化，再同步更新 API 文档
diff --git a/internal/adapter/claude/convert.go b/internal/adapter/claude/convert.go
index dbb5e1a..2233a65 100644
--- a/internal/adapter/claude/convert.go
+++ b/internal/adapter/claude/convert.go
@@ -4,7 +4,7 @@ import (
 	"ds2api/internal/claudeconv"
 )
 
-const defaultClaudeModel = "claude-sonnet-4-5"
+const defaultClaudeModel = "claude-sonnet-4-6"
 
 func convertClaudeToDeepSeek(claudeReq map[string]any, store ConfigReader) map[string]any {
 	return claudeconv.ConvertClaudeToDeepSeek(claudeReq, store, defaultClaudeModel)
diff --git a/internal/adapter/claude/deps.go b/internal/adapter/claude/deps.go
index 0088e81..7f82ba8 100644
--- a/internal/adapter/claude/deps.go
+++ b/internal/adapter/claude/deps.go
@@ -21,7 +21,7 @@ type DeepSeekCaller interface {
 }
 
 type ConfigReader interface {
-	ClaudeMapping() map[string]string
+	ModelAliases() map[string]string
 	CompatStripReferenceMarkers() bool
 }
 
diff --git a/internal/adapter/claude/deps_injection_test.go b/internal/adapter/claude/deps_injection_test.go
index c585b36..c880dc4 100644
--- a/internal/adapter/claude/deps_injection_test.go
+++ b/internal/adapter/claude/deps_injection_test.go
@@ -3,13 +3,13 @@ package claude
 import "testing"
 
 type mockClaudeConfig struct {
-	m map[string]string
+	aliases map[string]string
 }
 
-func (m mockClaudeConfig) ClaudeMapping() map[string]string { return m.m }
-func (mockClaudeConfig) CompatStripReferenceMarkers() bool  { return true }
+func (m mockClaudeConfig) ModelAliases() map[string]string { return m.aliases }
+func (mockClaudeConfig) CompatStripReferenceMarkers() bool { return true }
 
-func TestNormalizeClaudeRequestUsesConfigInterfaceMapping(t *testing.T) {
+func TestNormalizeClaudeRequestUsesGlobalAliasMapping(t *testing.T) {
 	req := map[string]any{
 		"model": "claude-opus-4-6",
 		"messages": []any{
@@ -17,9 +17,8 @@ func TestNormalizeClaudeRequestUsesConfigInterfaceMapping(t *testing.T) {
 		},
 	}
 	out, err := normalizeClaudeRequest(mockClaudeConfig{
-		m: map[string]string{
-			"fast": "deepseek-v4-flash",
-			"slow": "deepseek-v4-pro-search",
+		aliases: map[string]string{
+			"claude-opus-4-6": "deepseek-v4-pro-search",
 		},
 	}, req)
 	if err != nil {
@@ -32,3 +31,23 @@ func TestNormalizeClaudeRequestUsesConfigInterfaceMapping(t *testing.T) {
 		t.Fatalf("unexpected flags: thinking=%v search=%v", out.Standard.Thinking, out.Standard.Search)
 	}
 }
+
+func TestNormalizeClaudeRequestPrefersGlobalAliasMapping(t *testing.T) {
+	req := map[string]any{
+		"model": "claude-sonnet-4-6",
+		"messages": []any{
+			map[string]any{"role": "user", "content": "hello"},
+		},
+	}
+	out, err := normalizeClaudeRequest(mockClaudeConfig{
+		aliases: map[string]string{
+			"claude-sonnet-4-6": "deepseek-v4-flash",
+		},
+	}, req)
+	if err != nil {
+		t.Fatalf("normalizeClaudeRequest error: %v", err)
+	}
+	if out.Standard.ResolvedModel != "deepseek-v4-flash" {
+		t.Fatalf("expected global alias to win for explicit model, got=%q", out.Standard.ResolvedModel)
+	}
+}
diff --git a/internal/adapter/claude/handler_messages.go b/internal/adapter/claude/handler_messages.go
index 526d316..6ae23ab 100644
--- a/internal/adapter/claude/handler_messages.go
+++ b/internal/adapter/claude/handler_messages.go
@@ -44,7 +44,7 @@ func (h *Handler) proxyViaOpenAI(w http.ResponseWriter, r *http.Request, store C
 	model, _ := req["model"].(string)
 	stream := util.ToBool(req["stream"])
 
-	// Preserve claude_mapping (fast/slow/opus routing) while proxying via OpenAI.
+	// Use the shared global model resolver so Claude/OpenAI/Gemini stay consistent.
 	translateModel := model
 	if store != nil {
 		if norm, normErr := normalizeClaudeRequest(store, cloneMap(req)); normErr == nil && strings.TrimSpace(norm.Standard.ResolvedModel) != "" {
diff --git a/internal/adapter/claude/proxy_vercel_test.go b/internal/adapter/claude/proxy_vercel_test.go
index 56ff708..67e62de 100644
--- a/internal/adapter/claude/proxy_vercel_test.go
+++ b/internal/adapter/claude/proxy_vercel_test.go
@@ -9,12 +9,10 @@ import (
 )
 
 type claudeProxyStoreStub struct {
-	mapping map[string]string
+	aliases map[string]string
 }
 
-func (s claudeProxyStoreStub) ClaudeMapping() map[string]string {
-	return s.mapping
-}
+func (s claudeProxyStoreStub) ModelAliases() map[string]string { return s.aliases }
 
 func (claudeProxyStoreStub) CompatStripReferenceMarkers() bool { return true }
 
@@ -23,6 +21,27 @@ type openAIProxyStub struct {
 	body   string
 }
 
+func TestClaudeProxyViaOpenAIPrefersGlobalAliasMapping(t *testing.T) {
+	openAI := &openAIProxyCaptureStub{}
+	h := &Handler{
+		Store: claudeProxyStoreStub{
+			aliases: map[string]string{"claude-sonnet-4-6": "deepseek-v4-flash"},
+		},
+		OpenAI: openAI,
+	}
+	req := httptest.NewRequest(http.MethodPost, "/anthropic/v1/messages", strings.NewReader(`{"model":"claude-sonnet-4-6","messages":[{"role":"user","content":"hi"}],"stream":false}`))
+	rec := httptest.NewRecorder()
+
+	h.Messages(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("unexpected status: %d body=%s", rec.Code, rec.Body.String())
+	}
+	if got := strings.TrimSpace(openAI.seenModel); got != "deepseek-v4-flash" {
+		t.Fatalf("expected global alias mapped proxy model deepseek-v4-flash, got %q", got)
+	}
+}
+
 func (s openAIProxyStub) ChatCompletions(w http.ResponseWriter, _ *http.Request) {
 	if s.status == 0 {
 		s.status = http.StatusOK
@@ -68,10 +87,10 @@ func TestClaudeProxyViaOpenAIVercelPreparePassthrough(t *testing.T) {
 	}
 }
 
-func TestClaudeProxyViaOpenAIPreservesClaudeMapping(t *testing.T) {
+func TestClaudeProxyViaOpenAIUsesGlobalAliasMapping(t *testing.T) {
 	openAI := &openAIProxyCaptureStub{}
 	h := &Handler{
-		Store:  claudeProxyStoreStub{mapping: map[string]string{"fast": "deepseek-v4-flash", "slow": "deepseek-v4-pro"}},
+		Store:  claudeProxyStoreStub{aliases: map[string]string{"claude-3-opus": "deepseek-v4-pro"}},
 		OpenAI: openAI,
 	}
 	req := httptest.NewRequest(http.MethodPost, "/anthropic/v1/messages", strings.NewReader(`{"model":"claude-3-opus","messages":[{"role":"user","content":"hi"}],"stream":false}`))
diff --git a/internal/adapter/claude/stream_status_test.go b/internal/adapter/claude/stream_status_test.go
index a3d4633..2a2586f 100644
--- a/internal/adapter/claude/stream_status_test.go
+++ b/internal/adapter/claude/stream_status_test.go
@@ -21,12 +21,7 @@ func (streamStatusClaudeOpenAIStub) ChatCompletions(w http.ResponseWriter, _ *ht
 
 type streamStatusClaudeStoreStub struct{}
 
-func (streamStatusClaudeStoreStub) ClaudeMapping() map[string]string {
-	return map[string]string{
-		"fast": "deepseek-v4-flash",
-		"slow": "deepseek-v4-pro",
-	}
-}
+func (streamStatusClaudeStoreStub) ModelAliases() map[string]string { return nil }
 
 func (streamStatusClaudeStoreStub) CompatStripReferenceMarkers() bool { return true }
 
diff --git a/internal/admin/handler_config_import.go b/internal/admin/handler_config_import.go
index 7decbde..fe5faff 100644
--- a/internal/admin/handler_config_import.go
+++ b/internal/admin/handler_config_import.go
@@ -82,23 +82,6 @@ func (h *Handler) configImport(w http.ResponseWriter, r *http.Request) {
 				importedAccounts++
 			}
 
-			if len(incoming.ClaudeMapping) > 0 {
-				if next.ClaudeMapping == nil {
-					next.ClaudeMapping = map[string]string{}
-				}
-				for k, v := range incoming.ClaudeMapping {
-					next.ClaudeMapping[k] = v
-				}
-			}
-			if len(incoming.ClaudeModelMap) > 0 {
-				if next.ClaudeModelMap == nil {
-					next.ClaudeModelMap = map[string]string{}
-				}
-				for k, v := range incoming.ClaudeModelMap {
-					next.ClaudeModelMap[k] = v
-				}
-			}
-
 			if len(incoming.ModelAliases) > 0 {
 				if next.ModelAliases == nil {
 					next.ModelAliases = map[string]string{}
diff --git a/internal/admin/handler_config_read.go b/internal/admin/handler_config_read.go
index 20e5b1d..9fc876f 100644
--- a/internal/admin/handler_config_read.go
+++ b/internal/admin/handler_config_read.go
@@ -18,12 +18,7 @@ func (h *Handler) getConfig(w http.ResponseWriter, _ *http.Request) {
 		"env_source_present":    h.Store.HasEnvConfigSource(),
 		"env_writeback_enabled": h.Store.IsEnvWritebackEnabled(),
 		"config_path":           h.Store.ConfigPath(),
-		"claude_mapping": func() map[string]string {
-			if len(snap.ClaudeMapping) > 0 {
-				return snap.ClaudeMapping
-			}
-			return snap.ClaudeModelMap
-		}(),
+		"model_aliases":         snap.ModelAliases,
 	}
 	accounts := make([]map[string]any, 0, len(snap.Accounts))
 	for _, acc := range snap.Accounts {
diff --git a/internal/admin/handler_config_write.go b/internal/admin/handler_config_write.go
index 1929f26..7f6afb8 100644
--- a/internal/admin/handler_config_write.go
+++ b/internal/admin/handler_config_write.go
@@ -58,12 +58,12 @@ func (h *Handler) updateConfig(w http.ResponseWriter, r *http.Request) {
 			}
 			c.Accounts = accounts
 		}
-		if m, ok := req["claude_mapping"].(map[string]any); ok {
-			newMap := map[string]string{}
+		if m, ok := req["model_aliases"].(map[string]any); ok {
+			aliases := make(map[string]string, len(m))
 			for k, v := range m {
-				newMap[k] = fmt.Sprintf("%v", v)
+				aliases[k] = fmt.Sprintf("%v", v)
 			}
-			c.ClaudeMapping = newMap
+			c.ModelAliases = aliases
 		}
 		return nil
 	})
diff --git a/internal/admin/handler_settings_parse.go b/internal/admin/handler_settings_parse.go
index c02d421..0cc297e 100644
--- a/internal/admin/handler_settings_parse.go
+++ b/internal/admin/handler_settings_parse.go
@@ -21,7 +21,7 @@ func boolFrom(v any) bool {
 	}
 }
 
-func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *config.RuntimeConfig, *config.CompatConfig, *config.ResponsesConfig, *config.EmbeddingsConfig, *config.AutoDeleteConfig, *config.HistorySplitConfig, map[string]string, map[string]string, error) {
+func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *config.RuntimeConfig, *config.CompatConfig, *config.ResponsesConfig, *config.EmbeddingsConfig, *config.AutoDeleteConfig, *config.HistorySplitConfig, map[string]string, error) {
 	var (
 		adminCfg        *config.AdminConfig
 		runtimeCfg      *config.RuntimeConfig
@@ -30,7 +30,6 @@ func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *confi
 		embCfg          *config.EmbeddingsConfig
 		autoDeleteCfg   *config.AutoDeleteConfig
 		historySplitCfg *config.HistorySplitConfig
-		claudeMap       map[string]string
 		aliasMap        map[string]string
 	)
 
@@ -39,7 +38,7 @@ func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *confi
 		if v, exists := raw["jwt_expire_hours"]; exists {
 			n := intFrom(v)
 			if err := config.ValidateIntRange("admin.jwt_expire_hours", n, 1, 720, true); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			cfg.JWTExpireHours = n
 		}
@@ -51,33 +50,33 @@ func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *confi
 		if v, exists := raw["account_max_inflight"]; exists {
 			n := intFrom(v)
 			if err := config.ValidateIntRange("runtime.account_max_inflight", n, 1, 256, true); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			cfg.AccountMaxInflight = n
 		}
 		if v, exists := raw["account_max_queue"]; exists {
 			n := intFrom(v)
 			if err := config.ValidateIntRange("runtime.account_max_queue", n, 1, 200000, true); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			cfg.AccountMaxQueue = n
 		}
 		if v, exists := raw["global_max_inflight"]; exists {
 			n := intFrom(v)
 			if err := config.ValidateIntRange("runtime.global_max_inflight", n, 1, 200000, true); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			cfg.GlobalMaxInflight = n
 		}
 		if v, exists := raw["token_refresh_interval_hours"]; exists {
 			n := intFrom(v)
 			if err := config.ValidateIntRange("runtime.token_refresh_interval_hours", n, 1, 720, true); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			cfg.TokenRefreshIntervalHours = n
 		}
 		if cfg.AccountMaxInflight > 0 && cfg.GlobalMaxInflight > 0 && cfg.GlobalMaxInflight < cfg.AccountMaxInflight {
-			return nil, nil, nil, nil, nil, nil, nil, nil, nil, fmt.Errorf("runtime.global_max_inflight must be >= runtime.account_max_inflight")
+			return nil, nil, nil, nil, nil, nil, nil, nil, fmt.Errorf("runtime.global_max_inflight must be >= runtime.account_max_inflight")
 		}
 		runtimeCfg = cfg
 	}
@@ -100,7 +99,7 @@ func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *confi
 		if v, exists := raw["store_ttl_seconds"]; exists {
 			n := intFrom(v)
 			if err := config.ValidateIntRange("responses.store_ttl_seconds", n, 30, 86400, true); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			cfg.StoreTTLSeconds = n
 		}
@@ -112,27 +111,17 @@ func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *confi
 		if v, exists := raw["provider"]; exists {
 			p := strings.TrimSpace(fmt.Sprintf("%v", v))
 			if err := config.ValidateTrimmedString("embeddings.provider", p, false); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			cfg.Provider = p
 		}
 		embCfg = cfg
 	}
 
-	if raw, ok := req["claude_mapping"].(map[string]any); ok {
-		claudeMap = map[string]string{}
-		for k, v := range raw {
-			key := strings.TrimSpace(k)
-			val := strings.TrimSpace(fmt.Sprintf("%v", v))
-			if key == "" || val == "" {
-				continue
-			}
-			claudeMap[key] = val
-		}
-	}
-
 	if raw, ok := req["model_aliases"].(map[string]any); ok {
-		aliasMap = map[string]string{}
+		if aliasMap == nil {
+			aliasMap = map[string]string{}
+		}
 		for k, v := range raw {
 			key := strings.TrimSpace(k)
 			val := strings.TrimSpace(fmt.Sprintf("%v", v))
@@ -148,7 +137,7 @@ func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *confi
 		if v, exists := raw["mode"]; exists {
 			mode := strings.ToLower(strings.TrimSpace(fmt.Sprintf("%v", v)))
 			if err := config.ValidateAutoDeleteMode(mode); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			if mode == "" {
 				mode = "none"
@@ -170,15 +159,15 @@ func parseSettingsUpdateRequest(req map[string]any) (*config.AdminConfig, *confi
 		if v, exists := raw["trigger_after_turns"]; exists {
 			n := intFrom(v)
 			if err := config.ValidateIntRange("history_split.trigger_after_turns", n, 1, 1000, true); err != nil {
-				return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, nil, nil, err
 			}
 			cfg.TriggerAfterTurns = &n
 		}
 		if err := config.ValidateHistorySplitConfig(*cfg); err != nil {
-			return nil, nil, nil, nil, nil, nil, nil, nil, nil, err
+			return nil, nil, nil, nil, nil, nil, nil, nil, err
 		}
 		historySplitCfg = cfg
 	}
 
-	return adminCfg, runtimeCfg, compatCfg, respCfg, embCfg, autoDeleteCfg, historySplitCfg, claudeMap, aliasMap, nil
+	return adminCfg, runtimeCfg, compatCfg, respCfg, embCfg, autoDeleteCfg, historySplitCfg, aliasMap, nil
 }
diff --git a/internal/admin/handler_settings_read.go b/internal/admin/handler_settings_read.go
index dc060a8..2f9e7d2 100644
--- a/internal/admin/handler_settings_read.go
+++ b/internal/admin/handler_settings_read.go
@@ -34,7 +34,6 @@ func (h *Handler) getSettings(w http.ResponseWriter, _ *http.Request) {
 			"enabled":             h.Store.HistorySplitEnabled(),
 			"trigger_after_turns": h.Store.HistorySplitTriggerAfterTurns(),
 		},
-		"claude_mapping":    settingsClaudeMapping(snap),
 		"model_aliases":     snap.ModelAliases,
 		"env_backed":        h.Store.IsEnvBacked(),
 		"needs_vercel_sync": needsSync,
diff --git a/internal/admin/handler_settings_runtime.go b/internal/admin/handler_settings_runtime.go
index b090c38..a713c08 100644
--- a/internal/admin/handler_settings_runtime.go
+++ b/internal/admin/handler_settings_runtime.go
@@ -42,13 +42,3 @@ func defaultRuntimeRecommended(accountCount, maxPer int) int {
 	}
 	return accountCount * maxPer
 }
-
-func settingsClaudeMapping(c config.Config) map[string]string {
-	if len(c.ClaudeMapping) > 0 {
-		return c.ClaudeMapping
-	}
-	if len(c.ClaudeModelMap) > 0 {
-		return c.ClaudeModelMap
-	}
-	return map[string]string{"fast": "deepseek-v4-flash", "slow": "deepseek-v4-pro"}
-}
diff --git a/internal/admin/handler_settings_test.go b/internal/admin/handler_settings_test.go
index 4300cfe..e231739 100644
--- a/internal/admin/handler_settings_test.go
+++ b/internal/admin/handler_settings_test.go
@@ -346,6 +346,34 @@ func TestUpdateConfigLegacyKeysPreserveStructuredMetadata(t *testing.T) {
 	}
 }
 
+func TestUpdateConfigReplacesModelAliases(t *testing.T) {
+	h := newAdminTestHandler(t, `{
+		"keys":["k1"],
+		"model_aliases":{"claude-sonnet-4-6":"deepseek-v4-flash"}
+	}`)
+
+	payload := map[string]any{
+		"model_aliases": map[string]any{
+			"gpt-5.5": "deepseek-v4-pro",
+		},
+	}
+	b, _ := json.Marshal(payload)
+	req := httptest.NewRequest(http.MethodPost, "/admin/config", bytes.NewReader(b))
+	rec := httptest.NewRecorder()
+	h.updateConfig(rec, req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status=%d body=%s", rec.Code, rec.Body.String())
+	}
+
+	snap := h.Store.Snapshot()
+	if len(snap.ModelAliases) != 1 {
+		t.Fatalf("expected aliases to be replaced, got %#v", snap.ModelAliases)
+	}
+	if snap.ModelAliases["gpt-5.5"] != "deepseek-v4-pro" {
+		t.Fatalf("expected updated alias, got %#v", snap.ModelAliases)
+	}
+}
+
 func TestUpdateSettingsPasswordInvalidatesOldJWT(t *testing.T) {
 	hash := authn.HashAdminPassword("old-password")
 	h := newAdminTestHandler(t, `{"admin":{"password_hash":"`+hash+`"}}`)
diff --git a/internal/admin/handler_settings_write.go b/internal/admin/handler_settings_write.go
index ee4105a..2510d01 100644
--- a/internal/admin/handler_settings_write.go
+++ b/internal/admin/handler_settings_write.go
@@ -17,7 +17,7 @@ func (h *Handler) updateSettings(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	adminCfg, runtimeCfg, compatCfg, responsesCfg, embeddingsCfg, autoDeleteCfg, historySplitCfg, claudeMap, aliasMap, err := parseSettingsUpdateRequest(req)
+	adminCfg, runtimeCfg, compatCfg, responsesCfg, embeddingsCfg, autoDeleteCfg, historySplitCfg, aliasMap, err := parseSettingsUpdateRequest(req)
 	if err != nil {
 		writeJSON(w, http.StatusBadRequest, map[string]any{"detail": err.Error()})
 		return
@@ -75,10 +75,6 @@ func (h *Handler) updateSettings(w http.ResponseWriter, r *http.Request) {
 				c.HistorySplit.TriggerAfterTurns = historySplitCfg.TriggerAfterTurns
 			}
 		}
-		if claudeMap != nil {
-			c.ClaudeMapping = claudeMap
-			c.ClaudeModelMap = nil
-		}
 		if aliasMap != nil {
 			c.ModelAliases = aliasMap
 		}
diff --git a/internal/claudeconv/convert.go b/internal/claudeconv/convert.go
index aa64e5a..cd6e156 100644
--- a/internal/claudeconv/convert.go
+++ b/internal/claudeconv/convert.go
@@ -1,34 +1,23 @@
 package claudeconv
 
-import "strings"
+import (
+	"strings"
 
-type ClaudeMappingProvider interface {
-	ClaudeMapping() map[string]string
-}
+	"ds2api/internal/config"
+)
 
-func ConvertClaudeToDeepSeek(claudeReq map[string]any, mappingProvider ClaudeMappingProvider, defaultClaudeModel string) map[string]any {
+func ConvertClaudeToDeepSeek(claudeReq map[string]any, aliasProvider config.ModelAliasReader, defaultClaudeModel string) map[string]any {
 	messages, _ := claudeReq["messages"].([]any)
 	model, _ := claudeReq["model"].(string)
 	if model == "" {
 		model = defaultClaudeModel
 	}
 
-	mapping := map[string]string{}
-	if mappingProvider != nil {
-		mapping = mappingProvider.ClaudeMapping()
-	}
-	dsModel := mapping["fast"]
-	if dsModel == "" {
+	dsModel, ok := config.ResolveModel(aliasProvider, model)
+	if !ok || strings.TrimSpace(dsModel) == "" {
 		dsModel = "deepseek-v4-flash"
 	}
 
-	modelLower := strings.ToLower(model)
-	if strings.Contains(modelLower, "opus") || strings.Contains(modelLower, "reasoner") || strings.Contains(modelLower, "slow") {
-		if slow := mapping["slow"]; slow != "" {
-			dsModel = slow
-		}
-	}
-
 	convertedMessages := make([]any, 0, len(messages)+1)
 	if system, ok := claudeReq["system"].(string); ok && system != "" {
 		convertedMessages = append(convertedMessages, map[string]any{"role": "system", "content": system})
diff --git a/internal/config/codec.go b/internal/config/codec.go
index 11bf1d6..246df9b 100644
--- a/internal/config/codec.go
+++ b/internal/config/codec.go
@@ -26,12 +26,6 @@ func (c Config) MarshalJSON() ([]byte, error) {
 	if len(c.Proxies) > 0 {
 		m["proxies"] = c.Proxies
 	}
-	if len(c.ClaudeMapping) > 0 {
-		m["claude_mapping"] = c.ClaudeMapping
-	}
-	if len(c.ClaudeModelMap) > 0 {
-		m["claude_model_mapping"] = c.ClaudeModelMap
-	}
 	if len(c.ModelAliases) > 0 {
 		m["model_aliases"] = c.ModelAliases
 	}
@@ -88,13 +82,8 @@ func (c *Config) UnmarshalJSON(b []byte) error {
 				return fmt.Errorf("invalid field %q: %w", k, err)
 			}
 		case "claude_mapping":
-			if err := json.Unmarshal(v, &c.ClaudeMapping); err != nil {
-				return fmt.Errorf("invalid field %q: %w", k, err)
-			}
 		case "claude_model_mapping":
-			if err := json.Unmarshal(v, &c.ClaudeModelMap); err != nil {
-				return fmt.Errorf("invalid field %q: %w", k, err)
-			}
+			// Removed legacy mapping fields are ignored instead of persisted.
 		case "model_aliases":
 			if err := json.Unmarshal(v, &c.ModelAliases); err != nil {
 				return fmt.Errorf("invalid field %q: %w", k, err)
@@ -150,15 +139,13 @@ func (c *Config) UnmarshalJSON(b []byte) error {
 
 func (c Config) Clone() Config {
 	clone := Config{
-		Keys:           slices.Clone(c.Keys),
-		APIKeys:        slices.Clone(c.APIKeys),
-		Accounts:       slices.Clone(c.Accounts),
-		Proxies:        slices.Clone(c.Proxies),
-		ClaudeMapping:  cloneStringMap(c.ClaudeMapping),
-		ClaudeModelMap: cloneStringMap(c.ClaudeModelMap),
-		ModelAliases:   cloneStringMap(c.ModelAliases),
-		Admin:          c.Admin,
-		Runtime:        c.Runtime,
+		Keys:         slices.Clone(c.Keys),
+		APIKeys:      slices.Clone(c.APIKeys),
+		Accounts:     slices.Clone(c.Accounts),
+		Proxies:      slices.Clone(c.Proxies),
+		ModelAliases: cloneStringMap(c.ModelAliases),
+		Admin:        c.Admin,
+		Runtime:      c.Runtime,
 		Compat: CompatConfig{
 			WideInputStrictOutput: cloneBoolPtr(c.Compat.WideInputStrictOutput),
 			StripReferenceMarkers: cloneBoolPtr(c.Compat.StripReferenceMarkers),
diff --git a/internal/config/config.go b/internal/config/config.go
index dd1d5df..43856c6 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -12,8 +12,6 @@ type Config struct {
 	APIKeys          []APIKey           `json:"api_keys,omitempty"`
 	Accounts         []Account          `json:"accounts,omitempty"`
 	Proxies          []Proxy            `json:"proxies,omitempty"`
-	ClaudeMapping    map[string]string  `json:"claude_mapping,omitempty"`
-	ClaudeModelMap   map[string]string  `json:"claude_model_mapping,omitempty"`
 	ModelAliases     map[string]string  `json:"model_aliases,omitempty"`
 	Admin            AdminConfig        `json:"admin,omitempty"`
 	Runtime          RuntimeConfig      `json:"runtime,omitempty"`
@@ -100,6 +98,8 @@ func (c *Config) NormalizeCredentials() {
 		c.Accounts[i].Name = strings.TrimSpace(c.Accounts[i].Name)
 		c.Accounts[i].Remark = strings.TrimSpace(c.Accounts[i].Remark)
 	}
+
+	c.normalizeModelAliases()
 }
 
 // DropInvalidAccounts removes accounts that cannot be addressed by admin APIs
@@ -119,6 +119,27 @@ func (c *Config) DropInvalidAccounts() {
 	c.Accounts = kept
 }
 
+func (c *Config) normalizeModelAliases() {
+	if c == nil {
+		return
+	}
+
+	aliases := map[string]string{}
+	for k, v := range c.ModelAliases {
+		key := strings.TrimSpace(lower(k))
+		val := strings.TrimSpace(lower(v))
+		if key == "" || val == "" {
+			continue
+		}
+		aliases[key] = val
+	}
+	if len(aliases) == 0 {
+		c.ModelAliases = nil
+	} else {
+		c.ModelAliases = aliases
+	}
+}
+
 type CompatConfig struct {
 	WideInputStrictOutput *bool `json:"wide_input_strict_output,omitempty"`
 	StripReferenceMarkers *bool `json:"strip_reference_markers,omitempty"`
diff --git a/internal/config/config_edge_test.go b/internal/config/config_edge_test.go
index f1658ef..7741777 100644
--- a/internal/config/config_edge_test.go
+++ b/internal/config/config_edge_test.go
@@ -145,12 +145,9 @@ func TestConfigJSONRoundtrip(t *testing.T) {
 	trueVal := true
 	falseVal := false
 	cfg := Config{
-		Keys:     []string{"key1", "key2"},
-		Accounts: []Account{{Email: "user@example.com", Password: "pass", Token: "tok"}},
-		ClaudeMapping: map[string]string{
-			"fast": "deepseek-v4-flash",
-			"slow": "deepseek-v4-pro",
-		},
+		Keys:         []string{"key1", "key2"},
+		Accounts:     []Account{{Email: "user@example.com", Password: "pass", Token: "tok"}},
+		ModelAliases: map[string]string{"Claude-Sonnet-4-6": "DeepSeek-V4-Flash"},
 		AutoDelete: AutoDeleteConfig{
 			Mode: "single",
 		},
@@ -188,8 +185,8 @@ func TestConfigJSONRoundtrip(t *testing.T) {
 	if len(decoded.Accounts) != 1 || decoded.Accounts[0].Email != "user@example.com" {
 		t.Fatalf("unexpected accounts: %#v", decoded.Accounts)
 	}
-	if decoded.ClaudeMapping["fast"] != "deepseek-v4-flash" {
-		t.Fatalf("unexpected claude mapping: %#v", decoded.ClaudeMapping)
+	if decoded.ModelAliases["claude-sonnet-4-6"] != "deepseek-v4-flash" {
+		t.Fatalf("unexpected normalized model aliases: %#v", decoded.ModelAliases)
 	}
 	if decoded.Runtime.TokenRefreshIntervalHours != 12 {
 		t.Fatalf("unexpected runtime refresh interval: %#v", decoded.Runtime.TokenRefreshIntervalHours)
@@ -255,6 +252,23 @@ func TestConfigUnmarshalJSONPreservesUnknownFields(t *testing.T) {
 	}
 }
 
+func TestConfigUnmarshalJSONIgnoresRemovedLegacyModelMappings(t *testing.T) {
+	raw := `{"keys":["k1"],"accounts":[],"claude_mapping":{"fast":"deepseek-v4-pro"},"claude_model_mapping":{"slow":"deepseek-v4-pro"}}`
+	var cfg Config
+	if err := json.Unmarshal([]byte(raw), &cfg); err != nil {
+		t.Fatalf("unmarshal error: %v", err)
+	}
+	if len(cfg.ModelAliases) != 0 {
+		t.Fatalf("expected removed legacy mappings to be ignored, got %#v", cfg.ModelAliases)
+	}
+	if _, ok := cfg.AdditionalFields["claude_mapping"]; ok {
+		t.Fatalf("expected removed legacy field not to persist in additional fields: %#v", cfg.AdditionalFields)
+	}
+	if _, ok := cfg.AdditionalFields["claude_model_mapping"]; ok {
+		t.Fatalf("expected removed legacy field not to persist in additional fields: %#v", cfg.AdditionalFields)
+	}
+}
+
 // ─── Config.Clone ────────────────────────────────────────────────────
 
 func TestConfigCloneIsDeepCopy(t *testing.T) {
@@ -262,11 +276,9 @@ func TestConfigCloneIsDeepCopy(t *testing.T) {
 	trueVal := true
 	turns := 2
 	cfg := Config{
-		Keys:     []string{"key1"},
-		Accounts: []Account{{Email: "user@test.com", Token: "token"}},
-		ClaudeMapping: map[string]string{
-			"fast": "deepseek-v4-flash",
-		},
+		Keys:         []string{"key1"},
+		Accounts:     []Account{{Email: "user@test.com", Token: "token"}},
+		ModelAliases: map[string]string{"claude-sonnet-4-6": "deepseek-v4-flash"},
 		Compat: CompatConfig{
 			StripReferenceMarkers: &falseVal,
 		},
@@ -282,7 +294,7 @@ func TestConfigCloneIsDeepCopy(t *testing.T) {
 	// Modify original
 	cfg.Keys[0] = "modified"
 	cfg.Accounts[0].Email = "modified@test.com"
-	cfg.ClaudeMapping["fast"] = "modified-model"
+	cfg.ModelAliases["claude-sonnet-4-6"] = "modified-model"
 	if cfg.Compat.StripReferenceMarkers != nil {
 		*cfg.Compat.StripReferenceMarkers = true
 	}
@@ -300,8 +312,8 @@ func TestConfigCloneIsDeepCopy(t *testing.T) {
 	if cloned.Accounts[0].Email != "user@test.com" {
 		t.Fatalf("clone accounts was affected: %#v", cloned.Accounts)
 	}
-	if cloned.ClaudeMapping["fast"] != "deepseek-v4-flash" {
-		t.Fatalf("clone claude mapping was affected: %#v", cloned.ClaudeMapping)
+	if cloned.ModelAliases["claude-sonnet-4-6"] != "deepseek-v4-flash" {
+		t.Fatalf("clone model aliases was affected: %#v", cloned.ModelAliases)
 	}
 	if cloned.Compat.StripReferenceMarkers == nil || *cloned.Compat.StripReferenceMarkers {
 		t.Fatalf("clone compat was affected: %#v", cloned.Compat.StripReferenceMarkers)
@@ -652,25 +664,27 @@ func TestNormalizeCredentialsPrefersStructuredAPIKeys(t *testing.T) {
 	}
 }
 
-func TestStoreClaudeMapping(t *testing.T) {
-	t.Setenv("DS2API_CONFIG_JSON", `{"keys":[],"accounts":[],"claude_mapping":{"fast":"deepseek-v4-flash","slow":"deepseek-v4-pro"}}`)
+func TestStoreModelAliasesIncludesDefaultsAndOverrides(t *testing.T) {
+	t.Setenv("DS2API_CONFIG_JSON", `{"keys":[],"accounts":[],"model_aliases":{"claude-opus-4-6":"deepseek-v4-pro-search"}}`)
 	store := LoadStore()
-	mapping := store.ClaudeMapping()
-	if mapping["fast"] != "deepseek-v4-flash" {
-		t.Fatalf("unexpected fast mapping: %q", mapping["fast"])
+	aliases := store.ModelAliases()
+	if aliases["claude-sonnet-4-6"] != "deepseek-v4-flash" {
+		t.Fatalf("expected default alias to remain available, got %q", aliases["claude-sonnet-4-6"])
 	}
-	if mapping["slow"] != "deepseek-v4-pro" {
-		t.Fatalf("unexpected slow mapping: %q", mapping["slow"])
+	if aliases["claude-opus-4-6"] != "deepseek-v4-pro-search" {
+		t.Fatalf("expected custom alias override, got %q", aliases["claude-opus-4-6"])
 	}
 }
 
-func TestStoreClaudeMappingEmpty(t *testing.T) {
+func TestStoreModelAliasesDefault(t *testing.T) {
 	t.Setenv("DS2API_CONFIG_JSON", `{"keys":[],"accounts":[]}`)
 	store := LoadStore()
-	mapping := store.ClaudeMapping()
-	// Even without config mapping, there are defaults
-	if mapping == nil {
-		t.Fatal("expected non-nil mapping (may contain defaults)")
+	aliases := store.ModelAliases()
+	if aliases == nil {
+		t.Fatal("expected non-nil aliases")
+	}
+	if aliases["claude-sonnet-4-6"] != "deepseek-v4-flash" {
+		t.Fatalf("expected built-in alias, got %q", aliases["claude-sonnet-4-6"])
 	}
 }
 
diff --git a/internal/config/model_alias_test.go b/internal/config/model_alias_test.go
index c00aed6..f537b21 100644
--- a/internal/config/model_alias_test.go
+++ b/internal/config/model_alias_test.go
@@ -20,6 +20,47 @@ func TestResolveModelAlias(t *testing.T) {
 	}
 }
 
+func TestResolveLatestOpenAIAlias(t *testing.T) {
+	got, ok := ResolveModel(nil, "gpt-5.5")
+	if !ok || got != "deepseek-v4-flash" {
+		t.Fatalf("expected alias gpt-5.5 -> deepseek-v4-flash, got ok=%v model=%q", ok, got)
+	}
+}
+
+func TestResolveLatestClaudeAlias(t *testing.T) {
+	got, ok := ResolveModel(nil, "claude-sonnet-4-6")
+	if !ok || got != "deepseek-v4-flash" {
+		t.Fatalf("expected alias claude-sonnet-4-6 -> deepseek-v4-flash, got ok=%v model=%q", ok, got)
+	}
+}
+
+func TestResolveExpandedHistoricalAliases(t *testing.T) {
+	cases := []struct {
+		name  string
+		model string
+		want  string
+	}{
+		{name: "openai old chatgpt", model: "chatgpt-4o", want: "deepseek-v4-flash"},
+		{name: "openai codex max", model: "gpt-5.1-codex-max", want: "deepseek-v4-pro"},
+		{name: "openai deep research", model: "o3-deep-research", want: "deepseek-v4-pro-search"},
+		{name: "openai historical reasoning", model: "o1-preview", want: "deepseek-v4-pro"},
+		{name: "claude latest historical", model: "claude-3-5-sonnet-latest", want: "deepseek-v4-flash"},
+		{name: "claude historical opus", model: "claude-3-opus-20240229", want: "deepseek-v4-pro"},
+		{name: "claude historical haiku", model: "claude-3-haiku-20240307", want: "deepseek-v4-flash"},
+		{name: "gemini latest alias", model: "gemini-flash-latest", want: "deepseek-v4-flash"},
+		{name: "gemini historical pro", model: "gemini-1.5-pro", want: "deepseek-v4-pro"},
+		{name: "gemini vision legacy", model: "gemini-pro-vision", want: "deepseek-v4-vision"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, ok := ResolveModel(nil, tc.model)
+			if !ok || got != tc.want {
+				t.Fatalf("expected alias %s -> %s, got ok=%v model=%q", tc.model, tc.want, ok, got)
+			}
+		})
+	}
+}
+
 func TestResolveModelHeuristicReasoner(t *testing.T) {
 	got, ok := ResolveModel(nil, "o3-super")
 	if !ok || got != "deepseek-v4-pro" {
@@ -51,6 +92,19 @@ func TestResolveModelRejectsLegacyDeepSeekIDs(t *testing.T) {
 	}
 }
 
+func TestResolveModelRejectsRetiredHistoricalModels(t *testing.T) {
+	retiredModels := []string{
+		"claude-2.1",
+		"claude-instant-1.2",
+		"gpt-3.5-turbo",
+	}
+	for _, model := range retiredModels {
+		if got, ok := ResolveModel(nil, model); ok {
+			t.Fatalf("expected retired model %q to be rejected, got %q", model, got)
+		}
+	}
+}
+
 func TestResolveModelDirectDeepSeekExpert(t *testing.T) {
 	got, ok := ResolveModel(nil, "deepseek-v4-pro")
 	if !ok || got != "deepseek-v4-pro" {
diff --git a/internal/config/models.go b/internal/config/models.go
index d4d1afa..7b28ec3 100644
--- a/internal/config/models.go
+++ b/internal/config/models.go
@@ -26,11 +26,11 @@ var DeepSeekModels = []ModelInfo{
 var ClaudeModels = []ModelInfo{
 	// Current aliases
 	{ID: "claude-opus-4-6", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-sonnet-4-5", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
+	{ID: "claude-sonnet-4-6", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
 	{ID: "claude-haiku-4-5", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
 
-	// Current snapshots
-	{ID: "claude-opus-4-5-20251101", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
+	// Claude 4.x snapshots and prior aliases kept for compatibility
+	{ID: "claude-sonnet-4-5", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
 	{ID: "claude-opus-4-1", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
 	{ID: "claude-opus-4-1-20250805", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
 	{ID: "claude-opus-4-0", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
@@ -51,17 +51,6 @@ var ClaudeModels = []ModelInfo{
 	{ID: "claude-3-5-haiku-latest", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
 	{ID: "claude-3-5-haiku-20241022", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
 	{ID: "claude-3-haiku-20240307", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-
-	// Claude 2.x and 1.x (retired but accepted for compatibility)
-	{ID: "claude-2.1", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-2.0", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-1.3", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-1.2", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-1.1", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-1.0", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-instant-1.2", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-instant-1.1", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
-	{ID: "claude-instant-1.0", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
 }
 
 func GetModelConfig(model string) (thinking bool, search bool, ok bool) {
@@ -95,25 +84,103 @@ func IsSupportedDeepSeekModel(model string) bool {
 
 func DefaultModelAliases() map[string]string {
 	return map[string]string{
-		"gpt-4o":                 "deepseek-v4-flash",
-		"gpt-4.1":                "deepseek-v4-flash",
-		"gpt-4.1-mini":           "deepseek-v4-flash",
-		"gpt-4.1-nano":           "deepseek-v4-flash",
-		"gpt-5":                  "deepseek-v4-flash",
-		"gpt-5-mini":             "deepseek-v4-flash",
-		"gpt-5-codex":            "deepseek-v4-pro",
-		"o1":                     "deepseek-v4-pro",
-		"o1-mini":                "deepseek-v4-pro",
-		"o3":                     "deepseek-v4-pro",
-		"o3-mini":                "deepseek-v4-pro",
-		"claude-sonnet-4-5":      "deepseek-v4-flash",
-		"claude-haiku-4-5":       "deepseek-v4-flash",
-		"claude-opus-4-6":        "deepseek-v4-pro",
-		"claude-3-5-sonnet":      "deepseek-v4-flash",
-		"claude-3-5-haiku":       "deepseek-v4-flash",
-		"claude-3-opus":          "deepseek-v4-pro",
-		"gemini-2.5-pro":         "deepseek-v4-pro",
-		"gemini-2.5-flash":       "deepseek-v4-flash",
+		// OpenAI GPT / ChatGPT families
+		"chatgpt-4o":          "deepseek-v4-flash",
+		"gpt-4":               "deepseek-v4-flash",
+		"gpt-4-turbo":         "deepseek-v4-flash",
+		"gpt-4-turbo-preview": "deepseek-v4-flash",
+		"gpt-4.5-preview":     "deepseek-v4-flash",
+		"gpt-4o":              "deepseek-v4-flash",
+		"gpt-4o-mini":         "deepseek-v4-flash",
+		"gpt-4.1":             "deepseek-v4-flash",
+		"gpt-4.1-mini":        "deepseek-v4-flash",
+		"gpt-4.1-nano":        "deepseek-v4-flash",
+		"gpt-5":               "deepseek-v4-flash",
+		"gpt-5-chat":          "deepseek-v4-flash",
+		"gpt-5.1":             "deepseek-v4-flash",
+		"gpt-5.1-chat":        "deepseek-v4-flash",
+		"gpt-5.2":             "deepseek-v4-flash",
+		"gpt-5.2-chat":        "deepseek-v4-flash",
+		"gpt-5.3-chat":        "deepseek-v4-flash",
+		"gpt-5.4":             "deepseek-v4-flash",
+		"gpt-5.5":             "deepseek-v4-flash",
+		"gpt-5-mini":          "deepseek-v4-flash",
+		"gpt-5-nano":          "deepseek-v4-flash",
+		"gpt-5.4-mini":        "deepseek-v4-flash",
+		"gpt-5.4-nano":        "deepseek-v4-flash",
+		"gpt-5-pro":           "deepseek-v4-pro",
+		"gpt-5.2-pro":         "deepseek-v4-pro",
+		"gpt-5.4-pro":         "deepseek-v4-pro",
+		"gpt-5.5-pro":         "deepseek-v4-pro",
+		"gpt-5-codex":         "deepseek-v4-pro",
+		"gpt-5.1-codex":       "deepseek-v4-pro",
+		"gpt-5.1-codex-mini":  "deepseek-v4-pro",
+		"gpt-5.1-codex-max":   "deepseek-v4-pro",
+		"gpt-5.2-codex":       "deepseek-v4-pro",
+		"gpt-5.3-codex":       "deepseek-v4-pro",
+		"codex-mini-latest":   "deepseek-v4-pro",
+
+		// OpenAI reasoning / research families
+		"o1":                    "deepseek-v4-pro",
+		"o1-preview":            "deepseek-v4-pro",
+		"o1-mini":               "deepseek-v4-pro",
+		"o1-pro":                "deepseek-v4-pro",
+		"o3":                    "deepseek-v4-pro",
+		"o3-mini":               "deepseek-v4-pro",
+		"o3-pro":                "deepseek-v4-pro",
+		"o3-deep-research":      "deepseek-v4-pro-search",
+		"o4-mini":               "deepseek-v4-pro",
+		"o4-mini-deep-research": "deepseek-v4-pro-search",
+
+		// Claude current and historical aliases
+		"claude-opus-4-6":            "deepseek-v4-pro",
+		"claude-opus-4-1":            "deepseek-v4-pro",
+		"claude-opus-4-1-20250805":   "deepseek-v4-pro",
+		"claude-opus-4-0":            "deepseek-v4-pro",
+		"claude-opus-4-20250514":     "deepseek-v4-pro",
+		"claude-sonnet-4-6":          "deepseek-v4-flash",
+		"claude-sonnet-4-5":          "deepseek-v4-flash",
+		"claude-sonnet-4-5-20250929": "deepseek-v4-flash",
+		"claude-sonnet-4-0":          "deepseek-v4-flash",
+		"claude-sonnet-4-20250514":   "deepseek-v4-flash",
+		"claude-haiku-4-5":           "deepseek-v4-flash",
+		"claude-haiku-4-5-20251001":  "deepseek-v4-flash",
+		"claude-3-7-sonnet":          "deepseek-v4-flash",
+		"claude-3-7-sonnet-latest":   "deepseek-v4-flash",
+		"claude-3-7-sonnet-20250219": "deepseek-v4-flash",
+		"claude-3-5-sonnet":          "deepseek-v4-flash",
+		"claude-3-5-sonnet-latest":   "deepseek-v4-flash",
+		"claude-3-5-sonnet-20240620": "deepseek-v4-flash",
+		"claude-3-5-sonnet-20241022": "deepseek-v4-flash",
+		"claude-3-5-haiku":           "deepseek-v4-flash",
+		"claude-3-5-haiku-latest":    "deepseek-v4-flash",
+		"claude-3-5-haiku-20241022":  "deepseek-v4-flash",
+		"claude-3-opus":              "deepseek-v4-pro",
+		"claude-3-opus-20240229":     "deepseek-v4-pro",
+		"claude-3-sonnet":            "deepseek-v4-flash",
+		"claude-3-sonnet-20240229":   "deepseek-v4-flash",
+		"claude-3-haiku":             "deepseek-v4-flash",
+		"claude-3-haiku-20240307":    "deepseek-v4-flash",
+
+		// Gemini current and historical text / multimodal models
+		"gemini-pro":            "deepseek-v4-pro",
+		"gemini-pro-vision":     "deepseek-v4-vision",
+		"gemini-pro-latest":     "deepseek-v4-pro",
+		"gemini-flash-latest":   "deepseek-v4-flash",
+		"gemini-1.5-pro":        "deepseek-v4-pro",
+		"gemini-1.5-flash":      "deepseek-v4-flash",
+		"gemini-1.5-flash-8b":   "deepseek-v4-flash",
+		"gemini-2.0-flash":      "deepseek-v4-flash",
+		"gemini-2.0-flash-lite": "deepseek-v4-flash",
+		"gemini-2.5-pro":        "deepseek-v4-pro",
+		"gemini-2.5-flash":      "deepseek-v4-flash",
+		"gemini-2.5-flash-lite": "deepseek-v4-flash",
+		"gemini-3.1-pro":        "deepseek-v4-pro",
+		"gemini-3-pro":          "deepseek-v4-pro",
+		"gemini-3-flash":        "deepseek-v4-flash",
+		"gemini-3.1-flash":      "deepseek-v4-flash",
+		"gemini-3.1-flash-lite": "deepseek-v4-flash",
+
 		"llama-3.1-70b-instruct": "deepseek-v4-flash",
 		"qwen-max":               "deepseek-v4-flash",
 	}
@@ -124,6 +191,9 @@ func ResolveModel(store ModelAliasReader, requested string) (string, bool) {
 	if model == "" {
 		return "", false
 	}
+	if isRetiredHistoricalModel(model) {
+		return "", false
+	}
 	if IsSupportedDeepSeekModel(model) {
 		return model, true
 	}
@@ -179,6 +249,21 @@ func ResolveModel(store ModelAliasReader, requested string) (string, bool) {
 	}
 }
 
+func isRetiredHistoricalModel(model string) bool {
+	switch {
+	case strings.HasPrefix(model, "claude-1."):
+		return true
+	case strings.HasPrefix(model, "claude-2."):
+		return true
+	case strings.HasPrefix(model, "claude-instant-"):
+		return true
+	case strings.HasPrefix(model, "gpt-3.5"):
+		return true
+	default:
+		return false
+	}
+}
+
 func lower(s string) string {
 	b := []byte(s)
 	for i, c := range b {
diff --git a/internal/config/store_accessors.go b/internal/config/store_accessors.go
index b0a0f31..6849b85 100644
--- a/internal/config/store_accessors.go
+++ b/internal/config/store_accessors.go
@@ -6,18 +6,6 @@ import (
 	"strings"
 )
 
-func (s *Store) ClaudeMapping() map[string]string {
-	s.mu.RLock()
-	defer s.mu.RUnlock()
-	if len(s.cfg.ClaudeModelMap) > 0 {
-		return cloneStringMap(s.cfg.ClaudeModelMap)
-	}
-	if len(s.cfg.ClaudeMapping) > 0 {
-		return cloneStringMap(s.cfg.ClaudeMapping)
-	}
-	return map[string]string{"fast": "deepseek-v4-flash", "slow": "deepseek-v4-pro"}
-}
-
 func (s *Store) ModelAliases() map[string]string {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
diff --git a/internal/util/messages.go b/internal/util/messages.go
index b6920c0..3a43f24 100644
--- a/internal/util/messages.go
+++ b/internal/util/messages.go
@@ -6,7 +6,7 @@ import (
 	"ds2api/internal/prompt"
 )
 
-const ClaudeDefaultModel = "claude-sonnet-4-5"
+const ClaudeDefaultModel = "claude-sonnet-4-6"
 
 type Message struct {
 	Role    string `json:"role"`
diff --git a/internal/util/messages_test.go b/internal/util/messages_test.go
index e7fd822..077e903 100644
--- a/internal/util/messages_test.go
+++ b/internal/util/messages_test.go
@@ -104,6 +104,18 @@ func TestConvertClaudeToDeepSeek(t *testing.T) {
 	}
 }
 
+func TestConvertClaudeToDeepSeekUsesGlobalAliasResolution(t *testing.T) {
+	store := config.LoadStore()
+	req := map[string]any{
+		"model":    "claude-3-5-sonnet-latest",
+		"messages": []any{map[string]any{"role": "user", "content": "Hi"}},
+	}
+	out := ConvertClaudeToDeepSeek(req, store)
+	if out["model"] != "deepseek-v4-flash" {
+		t.Fatalf("expected global alias resolution, got model=%q", out["model"])
+	}
+}
+
 func contains(s, sub string) bool {
 	return len(s) >= len(sub) && (s == sub || len(sub) == 0 || (len(s) > 0 && (indexOf(s, sub) >= 0)))
 }
diff --git a/internal/util/util_edge_test.go b/internal/util/util_edge_test.go
index d168fdc..6084d9c 100644
--- a/internal/util/util_edge_test.go
+++ b/internal/util/util_edge_test.go
@@ -348,8 +348,7 @@ func TestConvertClaudeToDeepSeekNoSystem(t *testing.T) {
 	}
 }
 
-func TestConvertClaudeToDeepSeekOpusUsesSlowMapping(t *testing.T) {
-	t.Setenv("DS2API_CONFIG_JSON", `{"keys":[],"accounts":[],"claude_mapping":{"fast":"deepseek-v4-flash","slow":"deepseek-v4-pro"}}`)
+func TestConvertClaudeToDeepSeekOpusUsesGlobalAlias(t *testing.T) {
 	store := config.LoadStore()
 	req := map[string]any{
 		"model":    "claude-opus-4-6",
@@ -357,6 +356,19 @@ func TestConvertClaudeToDeepSeekOpusUsesSlowMapping(t *testing.T) {
 	}
 	out := ConvertClaudeToDeepSeek(req, store)
 	if out["model"] != "deepseek-v4-pro" {
-		t.Fatalf("expected opus to use slow mapping, got %q", out["model"])
+		t.Fatalf("expected opus to use global alias, got %q", out["model"])
+	}
+}
+
+func TestConvertClaudeToDeepSeekUsesExplicitModelAlias(t *testing.T) {
+	t.Setenv("DS2API_CONFIG_JSON", `{"keys":[],"accounts":[],"model_aliases":{"claude-sonnet-4-6":"deepseek-v4-pro-search"}}`)
+	store := config.LoadStore()
+	req := map[string]any{
+		"model":    "claude-sonnet-4-6",
+		"messages": []any{map[string]any{"role": "user", "content": "Hi"}},
+	}
+	out := ConvertClaudeToDeepSeek(req, store)
+	if out["model"] != "deepseek-v4-pro-search" {
+		t.Fatalf("expected explicit alias override, got %q", out["model"])
 	}
 }
diff --git a/webui/src/features/settings/ModelSection.jsx b/webui/src/features/settings/ModelSection.jsx
index b1a220e..d377ac5 100644
--- a/webui/src/features/settings/ModelSection.jsx
+++ b/webui/src/features/settings/ModelSection.jsx
@@ -2,26 +2,15 @@ export default function ModelSection({ t, form, setForm }) {
     return (
         <div className="bg-card border border-border rounded-xl p-5 space-y-4">
             <h3 className="font-semibold">{t('settings.modelTitle')}</h3>
-            <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
-                <label className="text-sm space-y-2">
-                    <span className="text-muted-foreground">{t('settings.claudeMapping')}</span>
-                    <textarea
-                        value={form.claude_mapping_text}
-                        onChange={(e) => setForm((prev) => ({ ...prev, claude_mapping_text: e.target.value }))}
-                        rows={8}
-                        className="w-full bg-background border border-border rounded-lg px-3 py-2 font-mono text-xs"
-                    />
-                </label>
-                <label className="text-sm space-y-2">
-                    <span className="text-muted-foreground">{t('settings.modelAliases')}</span>
-                    <textarea
-                        value={form.model_aliases_text}
-                        onChange={(e) => setForm((prev) => ({ ...prev, model_aliases_text: e.target.value }))}
-                        rows={8}
-                        className="w-full bg-background border border-border rounded-lg px-3 py-2 font-mono text-xs"
-                    />
-                </label>
-            </div>
+            <label className="text-sm space-y-2 block">
+                <span className="text-muted-foreground">{t('settings.modelAliases')}</span>
+                <textarea
+                    value={form.model_aliases_text}
+                    onChange={(e) => setForm((prev) => ({ ...prev, model_aliases_text: e.target.value }))}
+                    rows={12}
+                    className="w-full bg-background border border-border rounded-lg px-3 py-2 font-mono text-xs"
+                />
+            </label>
         </div>
     )
 }
diff --git a/webui/src/features/settings/useSettingsForm.js b/webui/src/features/settings/useSettingsForm.js
index c3428b2..6e9d80e 100644
--- a/webui/src/features/settings/useSettingsForm.js
+++ b/webui/src/features/settings/useSettingsForm.js
@@ -18,7 +18,6 @@ const DEFAULT_FORM = {
     embeddings: { provider: '' },
     auto_delete: { mode: 'none' },
     history_split: { enabled: true, trigger_after_turns: 1 },
-    claude_mapping_text: '{\n  "fast": "deepseek-v4-flash",\n  "slow": "deepseek-v4-pro"\n}',
     model_aliases_text: '{}',
 }
 
@@ -75,7 +74,6 @@ function fromServerForm(data) {
             enabled: data.history_split?.enabled ?? true,
             trigger_after_turns: Number(data.history_split?.trigger_after_turns || 1),
         },
-        claude_mapping_text: JSON.stringify(data.claude_mapping || {}, null, 2),
         model_aliases_text: JSON.stringify(data.model_aliases || {}, null, 2),
     }
 }
@@ -176,10 +174,8 @@ export function useSettingsForm({ apiFetch, t, onMessage, onRefresh, onForceLogo
     }, [loadSettings])
 
     const saveSettings = useCallback(async () => {
-        let claudeMapping = {}
         let modelAliases = {}
         try {
-            claudeMapping = parseJSONMap(form.claude_mapping_text, 'claude_mapping', t)
             modelAliases = parseJSONMap(form.model_aliases_text, 'model_aliases', t)
         } catch (e) {
             onMessage('error', e.message)
@@ -188,7 +184,6 @@ export function useSettingsForm({ apiFetch, t, onMessage, onRefresh, onForceLogo
 
         const payload = {
             ...toServerPayload(form),
-            claude_mapping: claudeMapping,
             model_aliases: modelAliases,
         }
 
diff --git a/webui/src/locales/en.json b/webui/src/locales/en.json
index a0f72a4..9b54959 100644
--- a/webui/src/locales/en.json
+++ b/webui/src/locales/en.json
@@ -383,8 +383,7 @@
         "compatibilityDesc": "Compatibility controls that keep stream output closer to the wire format or safer for the web UI.",
         "stripReferenceMarkers": "Strip [reference:N] markers",
         "modelTitle": "Model mapping",
-        "claudeMapping": "Claude mapping (JSON)",
-        "modelAliases": "Model aliases (JSON)",
+        "modelAliases": "Global model aliases (JSON)",
         "autoDeleteTitle": "Session Cleanup Policy",
         "autoDeleteDesc": "Choose how DeepSeek remote chat records are cleaned up after each request completes.",
         "autoDeleteMode": "Deletion mode",
diff --git a/webui/src/locales/zh.json b/webui/src/locales/zh.json
index e5ca592..37b8b2d 100644
--- a/webui/src/locales/zh.json
+++ b/webui/src/locales/zh.json
@@ -383,8 +383,7 @@
         "compatibilityDesc": "用于控制输出格式兼容性，避免把模型原始流里的标记直接暴露到前端。",
         "stripReferenceMarkers": "移除 [reference:N] 标记",
         "modelTitle": "模型映射",
-        "claudeMapping": "Claude 映射（JSON）",
-        "modelAliases": "模型别名（JSON）",
+        "modelAliases": "全局模型映射（JSON）",
         "autoDeleteTitle": "会话删除策略",
         "autoDeleteDesc": "选择每次请求完成后如何清理 DeepSeek 远端聊天记录。",
         "autoDeleteMode": "删除模式",