diff --git a/frontend/src/components/ModelAdapterModal.vue b/frontend/src/components/ModelAdapterModal.vue
index 4e36eba..2e784ab 100644
--- a/frontend/src/components/ModelAdapterModal.vue
+++ b/frontend/src/components/ModelAdapterModal.vue
@@ -7,6 +7,7 @@ import {
   createEmptyModelAdapter,
   normalizeModelAdapter,
   OPENAI_ENDPOINT_CHAT_COMPLETIONS,
+  OPENAI_ENDPOINT_CUSTOM,
   OPENAI_ENDPOINT_RESPONSES,
   OPENAI_EXTRA_PARAMS_DEFAULT_JSON,
 } from "@/state/appState";
@@ -35,6 +36,7 @@ const anthropicThinkingEffortOptions = [
 const openAIEndpointOptions = [
   { label: "/v1/responses", value: OPENAI_ENDPOINT_RESPONSES, icon: "icon-[mdi--api]" },
   { label: "/v1/chat/completions", value: OPENAI_ENDPOINT_CHAT_COMPLETIONS, icon: "icon-[mdi--message-text-outline]" },
+  { label: "自定义路径", value: OPENAI_ENDPOINT_CUSTOM, icon: "icon-[mdi--pencil-outline]" },
 ];
 
 const fieldTips = {
diff --git a/frontend/src/state/appState.js b/frontend/src/state/appState.js
index 01143da..858ec96 100644
--- a/frontend/src/state/appState.js
+++ b/frontend/src/state/appState.js
@@ -27,6 +27,7 @@ const SUPPORTED_ANTHROPIC_THINKING_EFFORTS = new Set(["low", "medium", "high", "
 export const ANTHROPIC_THINKING_EFFORT_DEFAULT = "xhigh";
 export const OPENAI_ENDPOINT_RESPONSES = "/v1/responses";
 export const OPENAI_ENDPOINT_CHAT_COMPLETIONS = "/v1/chat/completions";
+export const OPENAI_ENDPOINT_CUSTOM = "/custom";
 export const OPENAI_EXTRA_PARAMS_DEFAULT_JSON = `{
   "service_tier": "priority"
 }`;
@@ -34,7 +35,7 @@ export const EXTRA_PARAMS_DEFAULT_JSON = `{
 }`;
 export const CUSTOM_HEADERS_DEFAULT_JSON = `{
 }`;
-const SUPPORTED_OPENAI_ENDPOINTS = new Set([OPENAI_ENDPOINT_RESPONSES, OPENAI_ENDPOINT_CHAT_COMPLETIONS]);
+const SUPPORTED_OPENAI_ENDPOINTS = new Set([OPENAI_ENDPOINT_RESPONSES, OPENAI_ENDPOINT_CHAT_COMPLETIONS, OPENAI_ENDPOINT_CUSTOM]);
 const SUPPORTED_ROUTE_MODES = new Set(["local", "upstream"]);
 const PROXY_STATE_EVENT = "proxy:state";
 const USER_CONFIG_CHANGED_EVENT = "user-config:changed";
@@ -282,6 +283,9 @@ export function createEmptyModelAdapter() {
   };
 }
 
+// normalizeOpenAIEndpoint 归一化 endpoint 路径。
+// 支持三个预设值：/v1/responses、/v1/chat/completions、/custom（自定义路径）。
+// 选 /custom 时，用户需在接口地址栏填写完整请求 URL。
 function normalizeOpenAIEndpoint(value) {
   const text = asString(value).toLowerCase();
   if (!text) {
@@ -290,6 +294,10 @@ function normalizeOpenAIEndpoint(value) {
   return SUPPORTED_OPENAI_ENDPOINTS.has(text) ? text : "";
 }
 
+function isValidOpenAIEndpoint(value) {
+  return normalizeOpenAIEndpoint(value) !== "";
+}
+
 function validateJSONObject(value, label) {
   const text = asString(value);
   if (!text) {
@@ -426,8 +434,8 @@ export function validateModelAdapters(source) {
     if (adapter.type === "openai" && !SUPPORTED_REASONING_EFFORTS.has(adapter.reasoningEffort)) {
       return `${prefix} 的推理强度仅支持 low、medium、high、xhigh`;
     }
-    if (adapter.type === "openai" && !SUPPORTED_OPENAI_ENDPOINTS.has(adapter.openAIEndpoint)) {
-      return `${prefix} 的 OpenAI 端点仅支持 /v1/responses 或 /v1/chat/completions`;
+    if (adapter.type === "openai" && !isValidOpenAIEndpoint(adapter.openAIEndpoint)) {
+      return `${prefix} 的 OpenAI 端点仅支持 /v1/responses、/v1/chat/completions 或以 / 开头的自定义路径`;
     }
     if (adapter.type === "openai" && adapter.openAIExtraParamsEnabled) {
       const extraParamsError = validateOpenAIExtraParamsJSON(adapter.openAIExtraParamsJSON);
diff --git a/frontend/src/views/ModelEditor.vue b/frontend/src/views/ModelEditor.vue
index 02f1e0d..e373b75 100644
--- a/frontend/src/views/ModelEditor.vue
+++ b/frontend/src/views/ModelEditor.vue
@@ -17,6 +17,7 @@ import {
   isModelAdapterTestResultStale,
   normalizeModelAdapter,
   OPENAI_ENDPOINT_CHAT_COMPLETIONS,
+  OPENAI_ENDPOINT_CUSTOM,
   OPENAI_ENDPOINT_RESPONSES,
   OPENAI_EXTRA_PARAMS_DEFAULT_JSON,
   runModelAdapterTest,
@@ -50,6 +51,7 @@ const anthropicThinkingEffortOptions = [
 const openAIEndpointOptions = [
   { label: "/v1/responses", value: OPENAI_ENDPOINT_RESPONSES, icon: "icon-[mdi--api]" },
   { label: "/v1/chat/completions", value: OPENAI_ENDPOINT_CHAT_COMPLETIONS, icon: "icon-[mdi--message-text-outline]" },
+  { label: "自定义路径(请输入完整请求地址)", value: OPENAI_ENDPOINT_CUSTOM, icon: "icon-[mdi--pencil-outline]" },
 ];
 
 const editorIndex = ref(-1);
@@ -128,7 +130,7 @@ const fieldTips = {
   contextWindowTokens: "模型单次可接受的最大上下文 Token 数。留空时使用默认值。",
   reasoningEffort: "推理强度仅对部分支持 reasoning_effort 的模型生效，并不是所有模型都支持。越高通常越稳，但也可能更慢。",
   maxCompletionTokens: "单次回复允许生成的最大 Token 数。留空时使用默认值。",
-  openAIEndpoint: "OpenAI 兼容接口使用的协议端点。未选择时默认使用 /v1/responses。",
+  openAIEndpoint: "选择接口协议端点。选“自定义路径”时，请在接口地址栏填写完整请求地址（含 /chat/completions 或 /responses 路径后缀），系统会根据末段自动判断协议形态。",
   openAIExtraParams: "开启后会把 JSON 对象覆盖到 OpenAI 请求体。同名字段以这里为准。OpenAI service_tier 支持 auto、default、flex、scale、priority。",
   customHeaders: "开启后会把 JSON 对象覆盖到最终请求头。同名请求头以这里为准，值必须是字符串。",
   anthropicExtraParams: "开启后会把 JSON 对象覆盖到 Anthropic 请求体。同名字段以这里为准。",
diff --git a/internal/backend/agent/model/openai.go b/internal/backend/agent/model/openai.go
index 751b2b3..4012831 100644
--- a/internal/backend/agent/model/openai.go
+++ b/internal/backend/agent/model/openai.go
@@ -304,15 +304,67 @@ func OpenAIEndpointURL(baseURL string, endpoint string) string {
 	if !strings.HasPrefix(normalizedEndpoint, "/") {
 		normalizedEndpoint = "/" + normalizedEndpoint
 	}
+	// 规则0：自定义路径模式
+	// - baseURL 已含 endpoint 后缀（/chat/completions 或 /responses）→ 直接用 base
+	// - 否则追加 /chat/completions（默认协议形态，覆盖 Z.AI /v4 等场景）
+	if normalizedEndpoint == modelchannel.OpenAIEndpointCustom {
+		if OpenAIEndpointFromBaseURL(base) != "" {
+			return base
+		}
+		return base + "/chat/completions"
+	}
+	// 规则1：baseURL 已含 endpoint 后缀 → 直接用 base
 	if OpenAIEndpointFromBaseURL(base) != "" {
 		return base
 	}
-	if strings.HasSuffix(base, "/v1") && strings.HasPrefix(normalizedEndpoint, "/v1/") {
-		return base + strings.TrimPrefix(normalizedEndpoint, "/v1")
+	// 规则2：baseURL 以 /vN 结尾时，剥离 endpoint 的版本前缀（/v1/、/v2/ 等）
+	// 这样 base=.../v4 + endpoint=/v1/chat/completions → .../v4/chat/completions
+	if _, ok := trailingVersionSegment(base); ok {
+		if rest, stripped := stripEndpointVersionPrefix(normalizedEndpoint); stripped {
+			return base + rest
+		}
 	}
+	// 规则3：兜底原样拼接
 	return base + normalizedEndpoint
 }
 
+// trailingVersionSegment 检测 URL 末尾是否以 /vN 形式结尾（N 为数字），
+// 返回版本段（如 "v4"）和是否匹配。用于通用版本段去重。
+func trailingVersionSegment(base string) (string, bool) {
+	idx := strings.LastIndex(base, "/")
+	if idx < 0 {
+		return "", false
+	}
+	seg := base[idx+1:]
+	if len(seg) < 2 || seg[0] != 'v' {
+		return "", false
+	}
+	for i := 1; i < len(seg); i++ {
+		if seg[i] < '0' || seg[i] > '9' {
+			return "", false
+		}
+	}
+	return seg, true
+}
+
+// stripEndpointVersionPrefix 剥离 endpoint 路径开头的版本段前缀（/vN/），
+// 返回剩余路径和是否成功剥离。
+// /v1/chat/completions → ("/chat/completions", true)
+// /chat/completions    → ("", false)
+func stripEndpointVersionPrefix(endpoint string) (string, bool) {
+	if len(endpoint) < 4 || endpoint[0] != '/' || endpoint[1] != 'v' {
+		return "", false
+	}
+	i := 2
+	for i < len(endpoint) && endpoint[i] >= '0' && endpoint[i] <= '9' {
+		i++
+	}
+	if i == 2 || i >= len(endpoint) || endpoint[i] != '/' {
+		return "", false
+	}
+	return endpoint[i:], true
+}
+
 func ResolveOpenAIEndpoint(baseURL string, endpoint string) string {
 	if endpointFromURL := OpenAIEndpointFromBaseURL(baseURL); endpointFromURL != "" {
 		return endpointFromURL
@@ -377,11 +429,11 @@ func (adapter *OpenAIAdapter) Stream(ctx context.Context, req StreamRequest, sin
 	req.OpenAIEndpoint = endpoint
 	if req.RequestKnobs != nil {
 		req.RequestKnobs["openai_endpoint"] = endpoint
-		if endpoint == modelchannel.OpenAIEndpointResponses {
+		if modelchannel.OpenAIEndpointShape(endpoint) == "responses" {
 			req.RequestKnobs["max_output_tokens"] = req.MaxTokens
 		}
 	}
-	if endpoint == modelchannel.OpenAIEndpointResponses {
+	if modelchannel.OpenAIEndpointShape(endpoint) == "responses" {
 		return adapter.streamResponses(ctx, req, baseURL, apiKey, modelID, sink)
 	}
 	return adapter.streamChatCompletions(ctx, req, baseURL, apiKey, modelID, sink)
@@ -425,14 +477,14 @@ func (adapter *OpenAIAdapter) streamChatCompletions(ctx context.Context, req Str
 		recordLLMSummaryArtifact(req, buildLLMSummaryPayload(req, "openai", modelID, startedAt, time.Time{}, finishedAt, "", 0, 0, 0, 0, err))
 		return err
 	}
-	applyOpenAIThinkingDisable(bodyMap, req, baseURL, modelID, modelchannel.OpenAIEndpointChatCompletions)
+	applyOpenAIThinkingDisable(bodyMap, req, baseURL, modelID, req.OpenAIEndpoint)
 	if err := ApplyOpenAIExtraParams(bodyMap, req.OpenAIExtraParamsEnabled, req.OpenAIExtraParamsJSON); err != nil {
 		finishedAt = time.Now().UTC()
 		recordLLMSummaryArtifact(req, buildLLMSummaryPayload(req, "openai", modelID, startedAt, time.Time{}, finishedAt, "", 0, 0, 0, 0, err))
 		return err
 	}
 	body = bodyMap
-	requestURL := OpenAIEndpointURL(baseURL, modelchannel.OpenAIEndpointChatCompletions)
+	requestURL := OpenAIEndpointURL(baseURL, req.OpenAIEndpoint)
 	recordLLMRequestArtifact(req, "openai", modelID, "POST", requestURL, body)
 
 	payload, err := json.Marshal(body)
@@ -901,7 +953,7 @@ func (adapter *OpenAIAdapter) streamResponses(ctx context.Context, req StreamReq
 		recordLLMSummaryArtifact(req, buildLLMSummaryPayload(req, "openai", modelID, startedAt, time.Time{}, finishedAt, "", 0, 0, 0, 0, err))
 		return err
 	}
-	applyOpenAIThinkingDisable(bodyMap, req, baseURL, modelID, modelchannel.OpenAIEndpointResponses)
+	applyOpenAIThinkingDisable(bodyMap, req, baseURL, modelID, req.OpenAIEndpoint)
 	if err := ApplyOpenAIExtraParams(bodyMap, req.OpenAIExtraParamsEnabled, req.OpenAIExtraParamsJSON); err != nil {
 		finishedAt = time.Now().UTC()
 		recordLLMSummaryArtifact(req, buildLLMSummaryPayload(req, "openai", modelID, startedAt, time.Time{}, finishedAt, "", 0, 0, 0, 0, err))
@@ -909,7 +961,7 @@ func (adapter *OpenAIAdapter) streamResponses(ctx context.Context, req StreamReq
 	}
 	body = bodyMap
 
-	requestURL := OpenAIEndpointURL(baseURL, modelchannel.OpenAIEndpointResponses)
+	requestURL := OpenAIEndpointURL(baseURL, req.OpenAIEndpoint)
 	recordLLMRequestArtifact(req, "openai", modelID, "POST", requestURL, body)
 
 	payload, err := json.Marshal(body)
@@ -1819,7 +1871,7 @@ func applyOpenAIThinkingDisable(body map[string]any, req StreamRequest, baseURL
 		delete(body, "reasoning_effort")
 		setRequestKnob(req, "thinking_disabled_provider_param", "enable_thinking")
 	case "reasoning_none":
-		if endpoint == modelchannel.OpenAIEndpointResponses {
+		if modelchannel.OpenAIEndpointShape(endpoint) == "responses" {
 			body["reasoning"] = map[string]any{"effort": "none"}
 		} else {
 			body["reasoning_effort"] = "none"
diff --git a/internal/backend/server/config/types.go b/internal/backend/server/config/types.go
index 94fe1cb..f2c192a 100644
--- a/internal/backend/server/config/types.go
+++ b/internal/backend/server/config/types.go
@@ -154,7 +154,7 @@ func NormalizeModelAdapterConfigs(input []ModelAdapterConfig) ([]ModelAdapterCon
 		case next.Type == "openai" && next.ReasoningEffort == "":
 			return nil, errors.New("模型适配器 reasoningEffort 仅支持 low、medium、high、xhigh")
 		case next.Type == "openai" && next.OpenAIEndpoint == "":
-			return nil, errors.New("模型适配器 openAIEndpoint 仅支持 /v1/responses 或 /v1/chat/completions")
+			return nil, errors.New("模型适配器 openAIEndpoint 仅支持 /v1/responses、/v1/chat/completions 或 /custom（自定义路径）")
 		case next.Type == "openai" && next.OpenAIExtraParamsEnabled:
 			if err := validateJSONMap(next.OpenAIExtraParamsJSON, "openAIExtraParamsJSON"); err != nil {
 				return nil, err
diff --git a/internal/modelchannel/identity.go b/internal/modelchannel/identity.go
index 7084bfc..da498bc 100644
--- a/internal/modelchannel/identity.go
+++ b/internal/modelchannel/identity.go
@@ -13,6 +13,7 @@ const ChannelIDHexLength = 16
 const (
 	OpenAIEndpointResponses       = "/v1/responses"
 	OpenAIEndpointChatCompletions = "/v1/chat/completions"
+	OpenAIEndpointCustom          = "/custom"
 )
 
 func NormalizeBaseURL(raw string) (string, error) {
@@ -39,20 +40,37 @@ func NormalizeBaseURL(raw string) (string, error) {
 	return normalized, nil
 }
 
+// NormalizeOpenAIEndpoint 归一化 OpenAI endpoint 路径。
+// 支持三个预设值：/v1/responses、/v1/chat/completions、/custom（自定义路径）。
+// 选 /custom 时，用户需在接口地址栏填写完整请求 URL。
 func NormalizeOpenAIEndpoint(providerType string, endpoint string) string {
 	if strings.TrimSpace(strings.ToLower(providerType)) != "openai" {
 		return ""
 	}
-	switch strings.ToLower(strings.TrimSpace(endpoint)) {
-	case "", OpenAIEndpointResponses:
+	normalized := strings.TrimSpace(endpoint)
+	switch normalized {
+	case "":
 		return OpenAIEndpointResponses
-	case OpenAIEndpointChatCompletions:
-		return OpenAIEndpointChatCompletions
+	case OpenAIEndpointResponses, OpenAIEndpointChatCompletions, OpenAIEndpointCustom:
+		return normalized
 	default:
 		return ""
 	}
 }
 
+// OpenAIEndpointShape 根据 endpoint 路径末段推断协议形态。
+// 返回 "responses"（Responses API）或 "chat/completions"（Chat Completions API）。
+// 这样 /v1/chat/completions、/v4/chat/completions、/chat/completions 都走同一协议分支。
+func OpenAIEndpointShape(endpoint string) string {
+	lower := strings.ToLower(strings.TrimSpace(endpoint))
+	switch {
+	case strings.HasSuffix(lower, "/responses"):
+		return "responses"
+	default:
+		return "chat/completions"
+	}
+}
+
 func BuildLegacyChannelID(baseURL string, modelID string, apiKey string, name string) string {
 	return buildChannelID([]string{
 		strings.TrimSpace(baseURL),