diff --git a/backend/internal/service/account_header_override.go b/backend/internal/service/account_header_override.go
new file mode 100644
index 0000000000..80c32b648d
--- /dev/null
+++ b/backend/internal/service/account_header_override.go
@@ -0,0 +1,226 @@
+package service
+
+import (
+	"net/http"
+	"sort"
+	"strings"
+
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
+
+	"golang.org/x/net/http/httpguts"
+)
+
+// 请求头覆写（header override）：仅对 Anthropic / OpenAI 平台的 api_key 账号生效。
+// 管理员在账号上配置一组 header name -> value，转发到上游前用配置值覆盖同名请求头
+// （匹配不区分大小写）；value 为空的条目视为"未填写"，不参与覆盖。
+const (
+	credKeyHeaderOverrideEnabled = "header_override_enabled"
+	credKeyHeaderOverrides       = "header_overrides"
+
+	maxHeaderOverrideEntries     = 64
+	maxHeaderOverrideNameLength  = 200
+	maxHeaderOverrideValueLength = 8192
+)
+
+// headerOverrideBlockedNames 禁止覆写的请求头（小写）。
+//   - 连接控制/逐跳头：由 HTTP 栈管理，覆写会破坏请求传输；
+//   - host/content-length：由 Go 的 Request.Host / ContentLength 字段管理，header 覆写不生效或产生冲突；
+//   - authorization/x-api-key：上游认证头由账号凭据统一注入，禁止通过覆写篡改；
+//   - accept-encoding：强制压缩会破坏网关对上游流式响应（SSE/usage）的解析；
+//   - sec-websocket-*：WebSocket 握手头由拨号器管理（OpenAI WS 模式）；
+//   - session_id/conversation_id 等：逐请求会话隔离头，固定值会造成会话串扰。
+var headerOverrideBlockedNames = map[string]struct{}{
+	"host":                     {},
+	"content-length":           {},
+	"transfer-encoding":        {},
+	"connection":               {},
+	"keep-alive":               {},
+	"proxy-authenticate":       {},
+	"proxy-authorization":      {},
+	"proxy-connection":         {},
+	"te":                       {},
+	"trailer":                  {},
+	"upgrade":                  {},
+	"authorization":            {},
+	"x-api-key":                {},
+	"accept-encoding":          {},
+	"sec-websocket-key":        {},
+	"sec-websocket-version":    {},
+	"sec-websocket-extensions": {},
+	"sec-websocket-protocol":   {},
+	"sec-websocket-accept":     {},
+	"session_id":               {},
+	"conversation_id":          {},
+	"x-codex-turn-state":       {},
+	"x-codex-turn-metadata":    {},
+	"chatgpt-account-id":       {},
+}
+
+func isHeaderOverrideBlockedName(lowerName string) bool {
+	_, blocked := headerOverrideBlockedNames[lowerName]
+	return blocked
+}
+
+// IsHeaderOverrideEligible 报告账号类型是否支持请求头覆写。
+// 目前仅开放 Anthropic / OpenAI 两个平台的 api_key 账号。
+func (a *Account) IsHeaderOverrideEligible() bool {
+	if a == nil || a.Type != AccountTypeAPIKey {
+		return false
+	}
+	return a.Platform == PlatformAnthropic || a.Platform == PlatformOpenAI
+}
+
+// IsHeaderOverrideEnabled 报告账号是否启用了请求头覆写。
+func (a *Account) IsHeaderOverrideEnabled() bool {
+	if !a.IsHeaderOverrideEligible() || a.Credentials == nil {
+		return false
+	}
+	enabled, ok := a.Credentials[credKeyHeaderOverrideEnabled].(bool)
+	return ok && enabled
+}
+
+// GetHeaderOverrides 返回生效的请求头覆写表（key 统一小写）。
+// 未启用、不符合平台/类型条件或配置为空时返回 nil。
+// 空 value 的条目（模板占位）与非法/禁止的 header 名会被跳过。
+func (a *Account) GetHeaderOverrides() map[string]string {
+	if !a.IsHeaderOverrideEnabled() {
+		return nil
+	}
+	raw := stringMappingFromRaw(a.Credentials[credKeyHeaderOverrides])
+	if len(raw) == 0 {
+		return nil
+	}
+	result := make(map[string]string, len(raw))
+	for name, value := range raw {
+		lowerName := strings.ToLower(strings.TrimSpace(name))
+		value = strings.TrimSpace(value)
+		if lowerName == "" || value == "" {
+			continue
+		}
+		// 防御性过滤：保存路径已做校验，这里兜底未经 Normalize 落库的数据
+		if len(lowerName) > maxHeaderOverrideNameLength || len(value) > maxHeaderOverrideValueLength {
+			continue
+		}
+		if isHeaderOverrideBlockedName(lowerName) {
+			continue
+		}
+		if !httpguts.ValidHeaderFieldName(lowerName) || !httpguts.ValidHeaderFieldValue(value) {
+			continue
+		}
+		result[lowerName] = value
+	}
+	if len(result) == 0 {
+		return nil
+	}
+	return result
+}
+
+// ApplyHeaderOverrides 将账号配置的请求头覆写应用到出站请求头。
+// 对每个覆写条目：先删除所有大小写变体（转发链路会以 wire casing 直接写入 map，
+// 可能存在非 canonical key），再按已知 wire casing 写入，避免产生重复头。
+// 账号未启用或不符合条件时为 no-op，可安全地在 OAuth/api_key 共用的构建器中调用。
+func (a *Account) ApplyHeaderOverrides(h http.Header) {
+	if h == nil {
+		return
+	}
+	overrides := a.GetHeaderOverrides()
+	if len(overrides) == 0 {
+		return
+	}
+	names := make([]string, 0, len(overrides))
+	for name := range overrides {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	for _, name := range names {
+		for existing := range h {
+			if strings.EqualFold(existing, name) {
+				delete(h, existing)
+			}
+		}
+		h[resolveWireCasing(name)] = []string{overrides[name]}
+	}
+}
+
+// NormalizeHeaderOverrideCredentials 校验并原地规范化 credentials 中的请求头覆写字段。
+// 供账号创建/更新/批量更新的保存路径调用；credentials 未携带相关字段时为 no-op。
+// 规范化内容：header 名转小写并去除首尾空白，value 去除首尾空白，丢弃名和值均为空的条目。
+func NormalizeHeaderOverrideCredentials(credentials map[string]any) error {
+	if credentials == nil {
+		return nil
+	}
+	if raw, ok := credentials[credKeyHeaderOverrideEnabled]; ok && raw != nil {
+		if _, isBool := raw.(bool); !isBool {
+			return infraerrors.New(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"header_override_enabled must be a boolean")
+		}
+	}
+	raw, ok := credentials[credKeyHeaderOverrides]
+	if !ok || raw == nil {
+		return nil
+	}
+
+	var entries map[string]any
+	switch m := raw.(type) {
+	case map[string]any:
+		entries = m
+	case map[string]string:
+		entries = make(map[string]any, len(m))
+		for k, v := range m {
+			entries[k] = v
+		}
+	default:
+		return infraerrors.New(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+			"header_overrides must be an object of header name to string value")
+	}
+
+	if len(entries) > maxHeaderOverrideEntries {
+		return infraerrors.Newf(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+			"header_overrides supports at most %d entries", maxHeaderOverrideEntries)
+	}
+
+	normalized := make(map[string]any, len(entries))
+	for name, rawValue := range entries {
+		value, isString := rawValue.(string)
+		if !isString {
+			return infraerrors.Newf(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"header %q value must be a string", name)
+		}
+		lowerName := strings.ToLower(strings.TrimSpace(name))
+		value = strings.TrimSpace(value)
+		if lowerName == "" {
+			if value == "" {
+				continue // 丢弃完全为空的占位行
+			}
+			return infraerrors.New(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"header name must not be empty")
+		}
+		if len(lowerName) > maxHeaderOverrideNameLength {
+			return infraerrors.Newf(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"header name %q exceeds %d characters", lowerName, maxHeaderOverrideNameLength)
+		}
+		if !httpguts.ValidHeaderFieldName(lowerName) {
+			return infraerrors.Newf(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"invalid header name %q", lowerName)
+		}
+		if isHeaderOverrideBlockedName(lowerName) {
+			return infraerrors.Newf(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"header %q is not allowed to be overridden", lowerName)
+		}
+		if len(value) > maxHeaderOverrideValueLength {
+			return infraerrors.Newf(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"header %q value exceeds %d characters", lowerName, maxHeaderOverrideValueLength)
+		}
+		if !httpguts.ValidHeaderFieldValue(value) {
+			return infraerrors.Newf(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"header %q has an invalid value", lowerName)
+		}
+		if _, dup := normalized[lowerName]; dup {
+			return infraerrors.Newf(http.StatusBadRequest, "INVALID_HEADER_OVERRIDE",
+				"duplicate header name %q (matching is case-insensitive)", lowerName)
+		}
+		normalized[lowerName] = value
+	}
+	credentials[credKeyHeaderOverrides] = normalized
+	return nil
+}
diff --git a/backend/internal/service/account_header_override_test.go b/backend/internal/service/account_header_override_test.go
new file mode 100644
index 0000000000..56c95b3fcb
--- /dev/null
+++ b/backend/internal/service/account_header_override_test.go
@@ -0,0 +1,335 @@
+//go:build unit
+
+package service
+
+import (
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func headerOverrideTestAccount(platform, accountType string, credentials map[string]any) *Account {
+	return &Account{
+		Platform:    platform,
+		Type:        accountType,
+		Credentials: credentials,
+	}
+}
+
+func TestIsHeaderOverrideEligible(t *testing.T) {
+	tests := []struct {
+		name     string
+		platform string
+		accType  string
+		want     bool
+	}{
+		{"anthropic apikey", PlatformAnthropic, AccountTypeAPIKey, true},
+		{"openai apikey", PlatformOpenAI, AccountTypeAPIKey, true},
+		{"anthropic oauth", PlatformAnthropic, AccountTypeOAuth, false},
+		{"openai oauth", PlatformOpenAI, AccountTypeOAuth, false},
+		{"gemini apikey", PlatformGemini, AccountTypeAPIKey, false},
+		{"grok apikey", PlatformGrok, AccountTypeAPIKey, false},
+		{"antigravity apikey", PlatformAntigravity, AccountTypeAPIKey, false},
+		{"anthropic bedrock", PlatformAnthropic, AccountTypeBedrock, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			acc := headerOverrideTestAccount(tt.platform, tt.accType, nil)
+			require.Equal(t, tt.want, acc.IsHeaderOverrideEligible())
+		})
+	}
+
+	var nilAccount *Account
+	require.False(t, nilAccount.IsHeaderOverrideEligible())
+	require.False(t, nilAccount.IsHeaderOverrideEnabled())
+	require.Nil(t, nilAccount.GetHeaderOverrides())
+}
+
+func TestIsHeaderOverrideEnabled(t *testing.T) {
+	acc := headerOverrideTestAccount(PlatformAnthropic, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+	})
+	require.True(t, acc.IsHeaderOverrideEnabled())
+
+	// 未配置 / 非 bool / false 均视为未启用
+	require.False(t, headerOverrideTestAccount(PlatformAnthropic, AccountTypeAPIKey, nil).IsHeaderOverrideEnabled())
+	require.False(t, headerOverrideTestAccount(PlatformAnthropic, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: "true",
+	}).IsHeaderOverrideEnabled())
+	require.False(t, headerOverrideTestAccount(PlatformAnthropic, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: false,
+	}).IsHeaderOverrideEnabled())
+
+	// 不符合平台/类型条件时即使配置了 true 也不启用
+	require.False(t, headerOverrideTestAccount(PlatformAnthropic, AccountTypeOAuth, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+	}).IsHeaderOverrideEnabled())
+	require.False(t, headerOverrideTestAccount(PlatformGemini, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+	}).IsHeaderOverrideEnabled())
+}
+
+func TestGetHeaderOverrides(t *testing.T) {
+	acc := headerOverrideTestAccount(PlatformOpenAI, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+		credKeyHeaderOverrides: map[string]any{
+			"User-Agent":    "my-agent/1.0",  // 大写 key 归一化为小写
+			" X-App ":       "cli",           // 名称去空白
+			"x-empty":       "",              // 空 value（模板占位）跳过
+			"authorization": "Bearer leaked", // 禁止覆写的头跳过
+			"bad name":      "value",         // 非法 header 名跳过
+			"x-padded":      "  padded  ",    // value 去空白
+		},
+	})
+	overrides := acc.GetHeaderOverrides()
+	require.Equal(t, map[string]string{
+		"user-agent": "my-agent/1.0",
+		"x-app":      "cli",
+		"x-padded":   "padded",
+	}, overrides)
+
+	// 未启用时返回 nil
+	disabled := headerOverrideTestAccount(PlatformOpenAI, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrides: map[string]any{"user-agent": "x"},
+	})
+	require.Nil(t, disabled.GetHeaderOverrides())
+
+	// 启用但全部为空 value 时返回 nil
+	empty := headerOverrideTestAccount(PlatformOpenAI, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+		credKeyHeaderOverrides:       map[string]any{"user-agent": ""},
+	})
+	require.Nil(t, empty.GetHeaderOverrides())
+
+	// 未经 Normalize 落库的超长数据 / WebSocket 握手头在应用时被防御性跳过
+	oversizedValue := strings.Repeat("a", maxHeaderOverrideValueLength+1)
+	defensive := headerOverrideTestAccount(PlatformOpenAI, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+		credKeyHeaderOverrides: map[string]any{
+			"x-big":             oversizedValue,
+			"sec-websocket-key": "forged",
+			"x-ok":              "ok",
+		},
+	})
+	require.Equal(t, map[string]string{"x-ok": "ok"}, defensive.GetHeaderOverrides())
+}
+
+func TestApplyHeaderOverrides(t *testing.T) {
+	acc := headerOverrideTestAccount(PlatformAnthropic, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+		credKeyHeaderOverrides: map[string]any{
+			"user-agent":     "override-agent/2.0",
+			"anthropic-beta": "custom-beta-1",
+			"x-custom":       "custom-value",
+		},
+	})
+
+	h := http.Header{}
+	// 模拟转发链路：canonical key 与 wire casing 原样 key 混合存在
+	h.Set("User-Agent", "claude-cli/2.1.161 (external, cli)")
+	h["anthropic-beta"] = []string{"claude-code-20250219,oauth-2025-04-20"} // 非 canonical 原样 key
+	h.Set("Content-Type", "application/json")
+
+	acc.ApplyHeaderOverrides(h)
+
+	// user-agent 覆盖且只有一个值（已知头恢复 wire casing）
+	require.Equal(t, []string{"override-agent/2.0"}, h["User-Agent"])
+	// anthropic-beta：非 canonical 旧值被清除，写入 wire casing（小写）
+	require.Equal(t, []string{"custom-beta-1"}, h["anthropic-beta"])
+	require.Empty(t, h["Anthropic-Beta"])
+	// 新增头（未知头以小写原样键写入，与转发链路 wire casing 约定一致）
+	require.Equal(t, []string{"custom-value"}, h["x-custom"])
+	require.Equal(t, "custom-value", getHeaderRaw(h, "x-custom"))
+	// 未覆写的头不受影响
+	require.Equal(t, "application/json", h.Get("Content-Type"))
+
+	// 覆盖后不存在任何大小写重复
+	count := 0
+	for k := range h {
+		if k == "anthropic-beta" || k == "Anthropic-Beta" {
+			count++
+		}
+	}
+	require.Equal(t, 1, count)
+}
+
+func TestApplyHeaderOverridesNoOpPaths(t *testing.T) {
+	baseline := func() http.Header {
+		h := http.Header{}
+		h.Set("User-Agent", "orig")
+		return h
+	}
+
+	// OAuth 账号：即使配置了覆写也不生效
+	oauth := headerOverrideTestAccount(PlatformAnthropic, AccountTypeOAuth, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+		credKeyHeaderOverrides:       map[string]any{"user-agent": "hacked"},
+	})
+	h := baseline()
+	oauth.ApplyHeaderOverrides(h)
+	require.Equal(t, "orig", h.Get("User-Agent"))
+
+	// 未启用开关
+	off := headerOverrideTestAccount(PlatformAnthropic, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrides: map[string]any{"user-agent": "hacked"},
+	})
+	h = baseline()
+	off.ApplyHeaderOverrides(h)
+	require.Equal(t, "orig", h.Get("User-Agent"))
+
+	// 禁止覆写的头（authorization / x-api-key / host 等）不会被应用
+	blocked := headerOverrideTestAccount(PlatformOpenAI, AccountTypeAPIKey, map[string]any{
+		credKeyHeaderOverrideEnabled: true,
+		credKeyHeaderOverrides: map[string]any{
+			"Authorization":  "Bearer evil",
+			"X-Api-Key":      "evil",
+			"Host":           "evil.example.com",
+			"Content-Length": "0",
+		},
+	})
+	h = http.Header{}
+	h.Set("Authorization", "Bearer real-key")
+	blocked.ApplyHeaderOverrides(h)
+	require.Equal(t, "Bearer real-key", h.Get("Authorization"))
+	require.Empty(t, h.Get("X-Api-Key"))
+	require.Empty(t, h.Get("Host"))
+
+	// nil header 不 panic
+	blocked.ApplyHeaderOverrides(nil)
+}
+
+func TestNormalizeHeaderOverrideCredentials(t *testing.T) {
+	t.Run("nil credentials no-op", func(t *testing.T) {
+		require.NoError(t, NormalizeHeaderOverrideCredentials(nil))
+	})
+
+	t.Run("missing keys no-op", func(t *testing.T) {
+		creds := map[string]any{"api_key": "sk-xxx"}
+		require.NoError(t, NormalizeHeaderOverrideCredentials(creds))
+		_, exists := creds[credKeyHeaderOverrides]
+		require.False(t, exists)
+	})
+
+	t.Run("normalizes names and values", func(t *testing.T) {
+		creds := map[string]any{
+			credKeyHeaderOverrideEnabled: true,
+			credKeyHeaderOverrides: map[string]any{
+				" User-Agent ": " my-agent ",
+				"X-App":        "",
+				"":             "", // 完全空行被丢弃
+			},
+		}
+		require.NoError(t, NormalizeHeaderOverrideCredentials(creds))
+		require.Equal(t, map[string]any{
+			"user-agent": "my-agent",
+			"x-app":      "",
+		}, creds[credKeyHeaderOverrides])
+	})
+
+	t.Run("accepts map[string]string input", func(t *testing.T) {
+		creds := map[string]any{
+			credKeyHeaderOverrides: map[string]string{"X-App": "cli"},
+		}
+		require.NoError(t, NormalizeHeaderOverrideCredentials(creds))
+		require.Equal(t, map[string]any{"x-app": "cli"}, creds[credKeyHeaderOverrides])
+	})
+
+	t.Run("rejects non-bool enabled", func(t *testing.T) {
+		err := NormalizeHeaderOverrideCredentials(map[string]any{
+			credKeyHeaderOverrideEnabled: "yes",
+		})
+		require.Error(t, err)
+	})
+
+	t.Run("rejects non-object overrides", func(t *testing.T) {
+		err := NormalizeHeaderOverrideCredentials(map[string]any{
+			credKeyHeaderOverrides: []any{"user-agent"},
+		})
+		require.Error(t, err)
+	})
+
+	t.Run("rejects non-string value", func(t *testing.T) {
+		err := NormalizeHeaderOverrideCredentials(map[string]any{
+			credKeyHeaderOverrides: map[string]any{"x-app": 123},
+		})
+		require.Error(t, err)
+	})
+
+	t.Run("rejects invalid header name", func(t *testing.T) {
+		for _, name := range []string{"bad name", "bad:name", "bad\nname", "值"} {
+			err := NormalizeHeaderOverrideCredentials(map[string]any{
+				credKeyHeaderOverrides: map[string]any{name: "v"},
+			})
+			require.Error(t, err, "name %q should be rejected", name)
+		}
+	})
+
+	t.Run("rejects empty name with value", func(t *testing.T) {
+		err := NormalizeHeaderOverrideCredentials(map[string]any{
+			credKeyHeaderOverrides: map[string]any{"  ": "v"},
+		})
+		require.Error(t, err)
+	})
+
+	t.Run("rejects blocked headers", func(t *testing.T) {
+		for _, name := range []string{
+			"Authorization", "x-api-key", "Host", "content-length", "Transfer-Encoding",
+			"connection", "accept-encoding", "Sec-WebSocket-Key", "session_id",
+			"conversation_id", "x-codex-turn-state", "chatgpt-account-id",
+		} {
+			err := NormalizeHeaderOverrideCredentials(map[string]any{
+				credKeyHeaderOverrides: map[string]any{name: "v"},
+			})
+			require.Error(t, err, "blocked header %q should be rejected", name)
+		}
+	})
+
+	t.Run("allows tab inside value", func(t *testing.T) {
+		creds := map[string]any{
+			credKeyHeaderOverrides: map[string]any{"x-app": "a\tb"},
+		}
+		require.NoError(t, NormalizeHeaderOverrideCredentials(creds))
+		require.Equal(t, map[string]any{"x-app": "a\tb"}, creds[credKeyHeaderOverrides])
+	})
+
+	t.Run("rejects invalid value", func(t *testing.T) {
+		err := NormalizeHeaderOverrideCredentials(map[string]any{
+			credKeyHeaderOverrides: map[string]any{"x-app": "bad\nvalue"},
+		})
+		require.Error(t, err)
+	})
+
+	t.Run("rejects duplicate names case-insensitively", func(t *testing.T) {
+		err := NormalizeHeaderOverrideCredentials(map[string]any{
+			credKeyHeaderOverrides: map[string]any{
+				"User-Agent": "a",
+				"user-agent": "b",
+			},
+		})
+		require.Error(t, err)
+	})
+
+	t.Run("rejects too many entries", func(t *testing.T) {
+		entries := make(map[string]any, maxHeaderOverrideEntries+1)
+		for i := 0; i <= maxHeaderOverrideEntries; i++ {
+			entries["x-h-"+string(rune('a'+i%26))+string(rune('a'+(i/26)%26))+string(rune('a'+(i/676)%26))] = "v"
+		}
+		err := NormalizeHeaderOverrideCredentials(map[string]any{
+			credKeyHeaderOverrides: entries,
+		})
+		require.Error(t, err)
+	})
+
+	t.Run("rejects oversized value", func(t *testing.T) {
+		big := make([]byte, maxHeaderOverrideValueLength+1)
+		for i := range big {
+			big[i] = 'a'
+		}
+		err := NormalizeHeaderOverrideCredentials(map[string]any{
+			credKeyHeaderOverrides: map[string]any{"x-app": string(big)},
+		})
+		require.Error(t, err)
+	})
+}
diff --git a/backend/internal/service/account_test_service.go b/backend/internal/service/account_test_service.go
index 80a862b971..b598ac8ced 100644
--- a/backend/internal/service/account_test_service.go
+++ b/backend/internal/service/account_test_service.go
@@ -295,6 +295,9 @@ func (s *AccountTestService) testClaudeAccountConnection(c *gin.Context, account
 		setAnthropicAPIKeyAuthHeader(req.Header, account, authToken)
 	}
 
+	// 账号级请求头覆写：测试请求与真实转发保持一致的最终头
+	account.ApplyHeaderOverrides(req.Header)
+
 	// Get proxy URL
 	proxyURL := ""
 	if account.ProxyID != nil && account.Proxy != nil {
@@ -603,6 +606,9 @@ func (s *AccountTestService) testOpenAIAccountConnection(c *gin.Context, account
 		setOpenAIChatGPTAccountHeaders(req.Header, credentialAccount)
 	}
 
+	// 账号级请求头覆写：测试请求与真实转发保持一致的最终头
+	credentialAccount.ApplyHeaderOverrides(req.Header)
+
 	// Get proxy URL
 	proxyURL := ""
 	if account.ProxyID != nil && account.Proxy != nil {
@@ -756,6 +762,9 @@ func (s *AccountTestService) testOpenAIChatCompletionsConnection(
 	req.Header.Set("Accept", "text/event-stream")
 	req.Header.Set("Authorization", "Bearer "+authToken)
 
+	// 账号级请求头覆写：测试请求与真实转发保持一致的最终头
+	account.ApplyHeaderOverrides(req.Header)
+
 	proxyURL := ""
 	if account.ProxyID != nil && account.Proxy != nil {
 		proxyURL = account.Proxy.URL()
@@ -848,6 +857,9 @@ func (s *AccountTestService) testOpenAICompactConnection(c *gin.Context, account
 		setOpenAIChatGPTAccountHeaders(req.Header, account)
 	}
 
+	// 账号级请求头覆写：测试请求与真实转发保持一致的最终头
+	account.ApplyHeaderOverrides(req.Header)
+
 	proxyURL := ""
 	if account.ProxyID != nil && account.Proxy != nil {
 		proxyURL = account.Proxy.URL()
@@ -1599,6 +1611,9 @@ func (s *AccountTestService) testOpenAIImageAPIKey(c *gin.Context, ctx context.C
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("Authorization", "Bearer "+authToken)
 
+	// 账号级请求头覆写：测试请求与真实转发保持一致的最终头
+	account.ApplyHeaderOverrides(req.Header)
+
 	proxyURL := ""
 	if account.ProxyID != nil && account.Proxy != nil {
 		proxyURL = account.Proxy.URL()
diff --git a/backend/internal/service/admin_service.go b/backend/internal/service/admin_service.go
index ebf1e7e404..f1de60eb47 100644
--- a/backend/internal/service/admin_service.go
+++ b/backend/internal/service/admin_service.go
@@ -2691,6 +2691,11 @@ func (s *adminServiceImpl) CreateAccount(ctx context.Context, input *CreateAccou
 		}
 	}
 
+	// 校验并规范化请求头覆写配置（header 名小写化、格式检查）
+	if err := NormalizeHeaderOverrideCredentials(input.Credentials); err != nil {
+		return nil, err
+	}
+
 	account := &Account{
 		Name:        input.Name,
 		Notes:       normalizeAccountNotes(input.Notes),
@@ -2821,6 +2826,10 @@ func (s *adminServiceImpl) UpdateAccount(ctx context.Context, id int64, input *U
 		// 敏感子键采用"incoming 没提供就保留"的合并语义：前端响应已脱敏，
 		// 全对象 PUT 编辑时不会再带回 token，避免覆盖时清空已有凭证。
 		account.Credentials = MergePreservingSensitiveCreds(account.Credentials, input.Credentials)
+		// 校验并规范化请求头覆写配置（header 名小写化、格式检查）
+		if err := NormalizeHeaderOverrideCredentials(account.Credentials); err != nil {
+			return nil, err
+		}
 	}
 	// Extra 使用 map：需要区分“未提供(nil)”与“显式清空({})”。
 	// 关闭配额限制时前端会删除 quota_* 键并提交 extra:{}，此时也必须落库。
@@ -3039,6 +3048,11 @@ func (s *adminServiceImpl) BulkUpdateAccounts(ctx context.Context, input *BulkUp
 		}
 	}
 
+	// 校验并规范化请求头覆写配置（批量路径为 JSONB 顶层 key 合并，直接校验增量即可）
+	if err := NormalizeHeaderOverrideCredentials(input.Credentials); err != nil {
+		return nil, err
+	}
+
 	// Prepare bulk updates for columns and JSONB fields.
 	repoUpdates := AccountBulkUpdate{
 		Credentials: input.Credentials,
diff --git a/backend/internal/service/gateway_service.go b/backend/internal/service/gateway_service.go
index 54035345d9..e683fc5463 100644
--- a/backend/internal/service/gateway_service.go
+++ b/backend/internal/service/gateway_service.go
@@ -5956,6 +5956,9 @@ func (s *GatewayService) buildUpstreamRequestAnthropicAPIKeyPassthrough(
 		setHeaderRaw(req.Header, "anthropic-version", "2023-06-01")
 	}
 
+	// 账号级请求头覆写（最终生效，覆盖上面所有来源的同名头）
+	account.ApplyHeaderOverrides(req.Header)
+
 	return req, body, nil
 }
 
@@ -6959,6 +6962,10 @@ func (s *GatewayService) buildUpstreamRequest(ctx context.Context, c *gin.Contex
 		}
 	}
 
+	// 账号级请求头覆写（仅 anthropic/openai api_key 账号启用时生效；OAuth 路径 no-op）。
+	// 放在所有 header 逻辑之后，确保配置值对同名头拥有最终决定权。
+	account.ApplyHeaderOverrides(req.Header)
+
 	// === DEBUG: 打印上游转发请求（headers + body 摘要），与 CLIENT_ORIGINAL 对比 ===
 	s.debugLogGatewaySnapshot("UPSTREAM_FORWARD", req.Header, body, map[string]string{
 		"url":                 req.URL.String(),
@@ -10445,6 +10452,9 @@ func (s *GatewayService) buildCountTokensRequestAnthropicAPIKeyPassthrough(
 		req.Header.Set("anthropic-version", "2023-06-01")
 	}
 
+	// 账号级请求头覆写（最终生效，覆盖上面所有来源的同名头）
+	account.ApplyHeaderOverrides(req.Header)
+
 	return req, nil
 }
 
@@ -10578,6 +10588,9 @@ func (s *GatewayService) buildCountTokensRequest(ctx context.Context, c *gin.Con
 		}
 	}
 
+	// 账号级请求头覆写（仅 anthropic/openai api_key 账号启用时生效；OAuth 路径 no-op）
+	account.ApplyHeaderOverrides(req.Header)
+
 	if c != nil && tokenType == "oauth" {
 		c.Set(claudeMimicDebugInfoKey, buildClaudeMimicDebugLine(req, body, account, tokenType, mimicClaudeCode))
 	}
diff --git a/backend/internal/service/openai_apikey_responses_probe.go b/backend/internal/service/openai_apikey_responses_probe.go
index 64f963ab9b..10cf050029 100644
--- a/backend/internal/service/openai_apikey_responses_probe.go
+++ b/backend/internal/service/openai_apikey_responses_probe.go
@@ -149,6 +149,9 @@ func (s *AccountTestService) ProbeOpenAIAPIKeyResponsesSupport(ctx context.Conte
 	req.Header.Set("Authorization", "Bearer "+apiKey)
 	req.Header.Set("Accept", "application/json")
 
+	// 账号级请求头覆写：能力探测与真实转发保持一致的最终头
+	account.ApplyHeaderOverrides(req.Header)
+
 	proxyURL := ""
 	if account.ProxyID != nil && account.Proxy != nil {
 		proxyURL = account.Proxy.URL()
diff --git a/backend/internal/service/openai_embeddings.go b/backend/internal/service/openai_embeddings.go
index 0fb3fff1f7..fb2dc5ccbb 100644
--- a/backend/internal/service/openai_embeddings.go
+++ b/backend/internal/service/openai_embeddings.go
@@ -82,6 +82,9 @@ func (s *OpenAIGatewayService) ForwardEmbeddings(
 		upstreamReq.Header.Set("user-agent", customUA)
 	}
 
+	// 账号级请求头覆写（仅 openai api_key 账号启用时生效）
+	account.ApplyHeaderOverrides(upstreamReq.Header)
+
 	proxyURL := ""
 	if account.Proxy != nil {
 		proxyURL = account.Proxy.URL()
diff --git a/backend/internal/service/openai_gateway_chat_completions_raw.go b/backend/internal/service/openai_gateway_chat_completions_raw.go
index 6bcb6718b7..348213a992 100644
--- a/backend/internal/service/openai_gateway_chat_completions_raw.go
+++ b/backend/internal/service/openai_gateway_chat_completions_raw.go
@@ -166,6 +166,9 @@ func (s *OpenAIGatewayService) forwardAsRawChatCompletions(
 		upstreamReq.Header.Set("user-agent", "sub2api-grok/1.0")
 	}
 
+	// 账号级请求头覆写（仅 openai api_key 账号启用时生效）
+	account.ApplyHeaderOverrides(upstreamReq.Header)
+
 	// 6. Send request
 	proxyURL := ""
 	if account.Proxy != nil {
diff --git a/backend/internal/service/openai_gateway_count_tokens.go b/backend/internal/service/openai_gateway_count_tokens.go
index 4a01b143e9..7518a6073a 100644
--- a/backend/internal/service/openai_gateway_count_tokens.go
+++ b/backend/internal/service/openai_gateway_count_tokens.go
@@ -231,6 +231,9 @@ func (s *OpenAIGatewayService) buildInputTokensUpstreamRequest(
 		}
 	}
 
+	// 账号级请求头覆写（仅 openai api_key 账号启用时生效；OAuth 路径 no-op）
+	account.ApplyHeaderOverrides(req.Header)
+
 	return req, nil
 }
 
diff --git a/backend/internal/service/openai_gateway_responses_chat_fallback.go b/backend/internal/service/openai_gateway_responses_chat_fallback.go
index d33df4c19d..c499bec778 100644
--- a/backend/internal/service/openai_gateway_responses_chat_fallback.go
+++ b/backend/internal/service/openai_gateway_responses_chat_fallback.go
@@ -138,6 +138,9 @@ func (s *OpenAIGatewayService) forwardResponsesViaRawChatCompletions(
 		upstreamReq.Header.Set("user-agent", customUA)
 	}
 
+	// 账号级请求头覆写（仅 openai api_key 账号启用时生效）
+	account.ApplyHeaderOverrides(upstreamReq.Header)
+
 	proxyURL := ""
 	if account.Proxy != nil {
 		proxyURL = account.Proxy.URL()
diff --git a/backend/internal/service/openai_gateway_service.go b/backend/internal/service/openai_gateway_service.go
index dd3d48aed0..f13c44f3a6 100644
--- a/backend/internal/service/openai_gateway_service.go
+++ b/backend/internal/service/openai_gateway_service.go
@@ -3783,6 +3783,9 @@ func (s *OpenAIGatewayService) buildUpstreamRequestOpenAIPassthrough(
 		req.Header.Set("content-type", "application/json")
 	}
 
+	// 账号级请求头覆写（仅 openai api_key 账号启用时生效；OAuth 路径 no-op）
+	account.ApplyHeaderOverrides(req.Header)
+
 	return req, nil
 }
 
@@ -4568,6 +4571,9 @@ func (s *OpenAIGatewayService) buildUpstreamRequest(ctx context.Context, c *gin.
 		req.Header.Set("content-type", "application/json")
 	}
 
+	// 账号级请求头覆写（仅 openai api_key 账号启用时生效；OAuth 路径 no-op）
+	account.ApplyHeaderOverrides(req.Header)
+
 	return req, nil
 }
 
diff --git a/backend/internal/service/openai_images.go b/backend/internal/service/openai_images.go
index 7081653d80..09472fbaf1 100644
--- a/backend/internal/service/openai_images.go
+++ b/backend/internal/service/openai_images.go
@@ -760,6 +760,8 @@ func (s *OpenAIGatewayService) buildOpenAIImagesRequest(
 	if strings.TrimSpace(contentType) != "" {
 		req.Header.Set("Content-Type", contentType)
 	}
+	// 账号级请求头覆写（仅 openai api_key 账号启用时生效；OAuth 路径 no-op）
+	account.ApplyHeaderOverrides(req.Header)
 	return req, nil
 }
 
diff --git a/backend/internal/service/openai_ws_forwarder.go b/backend/internal/service/openai_ws_forwarder.go
index fcc4b98064..bbca9776ab 100644
--- a/backend/internal/service/openai_ws_forwarder.go
+++ b/backend/internal/service/openai_ws_forwarder.go
@@ -1183,6 +1183,10 @@ func (s *OpenAIGatewayService) buildOpenAIWSHeaders(
 		headers.Set("user-agent", codexCLIUserAgent)
 	}
 
+	// 账号级请求头覆写（仅 openai api_key 账号启用时生效；OAuth 路径 no-op）。
+	// 覆盖所有 WS 模式（ctx_pool/dedicated/passthrough）的握手头。
+	account.ApplyHeaderOverrides(headers)
+
 	return headers, sessionResolution, nil
 }
 
diff --git a/backend/internal/service/upstream_models.go b/backend/internal/service/upstream_models.go
index ee3e6bfc04..e9fa7de451 100644
--- a/backend/internal/service/upstream_models.go
+++ b/backend/internal/service/upstream_models.go
@@ -208,6 +208,8 @@ func (s *AccountTestService) buildAnthropicUpstreamModelsRequest(ctx context.Con
 	} else {
 		setAnthropicAPIKeyAuthHeader(req.Header, account, apiKeyAuthToken)
 	}
+	// 账号级请求头覆写：模型列表探测与真实转发保持一致的最终头
+	account.ApplyHeaderOverrides(req.Header)
 	return req, nil
 }
 
@@ -277,6 +279,8 @@ func (s *AccountTestService) buildOpenAIUpstreamModelsRequest(ctx context.Contex
 	}
 	req.Header.Set("Accept", "application/json")
 	req.Header.Set("Authorization", "Bearer "+apiKey)
+	// 账号级请求头覆写：模型列表探测与真实转发保持一致的最终头
+	account.ApplyHeaderOverrides(req.Header)
 	return req, nil
 }
 
diff --git a/frontend/src/components/account/BulkEditAccountModal.vue b/frontend/src/components/account/BulkEditAccountModal.vue
index d24488b47a..7ce016810e 100644
--- a/frontend/src/components/account/BulkEditAccountModal.vue
+++ b/frontend/src/components/account/BulkEditAccountModal.vue
@@ -486,6 +486,125 @@
         </div>
       </div>
 
+      <!-- Header Override (anthropic/openai apikey only) -->
+      <div v-if="allHeaderOverrideCapable" class="border-t border-gray-200 pt-4 dark:border-dark-600">
+        <div class="flex items-center justify-between">
+          <div class="flex-1 pr-4">
+            <label
+              id="bulk-edit-header-override-label"
+              class="input-label mb-0"
+              for="bulk-edit-header-override-enabled"
+            >
+              {{ t('admin.accounts.headerOverride.title') }}
+            </label>
+            <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
+              {{ t('admin.accounts.headerOverride.hint') }}
+            </p>
+          </div>
+          <input
+            v-model="enableHeaderOverride"
+            id="bulk-edit-header-override-enabled"
+            type="checkbox"
+            aria-controls="bulk-edit-header-override-body"
+            class="rounded border-gray-300 text-primary-600 focus:ring-primary-500"
+          />
+        </div>
+        <div v-if="enableHeaderOverride" id="bulk-edit-header-override-body" class="mt-3 space-y-3">
+          <button
+            type="button"
+            :class="[
+              'relative inline-flex h-6 w-11 flex-shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors duration-200 ease-in-out focus:outline-none focus:ring-2 focus:ring-primary-500 focus:ring-offset-2',
+              headerOverrideEnabled ? 'bg-primary-600' : 'bg-gray-200 dark:bg-dark-600'
+            ]"
+            @click="headerOverrideEnabled = !headerOverrideEnabled"
+          >
+            <span
+              :class="[
+                'pointer-events-none inline-block h-5 w-5 transform rounded-full bg-white shadow ring-0 transition duration-200 ease-in-out',
+                headerOverrideEnabled ? 'translate-x-5' : 'translate-x-0'
+              ]"
+            />
+          </button>
+
+          <div v-if="headerOverrideEnabled" class="space-y-3">
+            <div class="rounded-lg bg-blue-50 p-3 dark:bg-blue-900/20">
+              <p class="text-xs text-blue-700 dark:text-blue-400">
+                <Icon name="exclamationCircle" size="sm" class="mr-1 inline" :stroke-width="2" />
+                {{ t('admin.accounts.headerOverride.info') }}
+              </p>
+            </div>
+
+            <div v-if="headerOverrideRows.length > 0" class="space-y-2">
+              <div
+                v-for="(row, index) in headerOverrideRows"
+                :key="getHeaderOverrideRowKey(row)"
+                class="flex items-center gap-2"
+              >
+                <input
+                  v-model="row.name"
+                  type="text"
+                  class="input flex-1"
+                  :placeholder="t('admin.accounts.headerOverride.namePlaceholder')"
+                />
+                <input
+                  v-model="row.value"
+                  type="text"
+                  class="input flex-1"
+                  :placeholder="t('admin.accounts.headerOverride.valuePlaceholder')"
+                />
+                <button
+                  type="button"
+                  class="rounded-lg p-2 text-red-500 transition-colors hover:bg-red-50 hover:text-red-600 dark:hover:bg-red-900/20"
+                  @click="removeHeaderOverrideRow(index)"
+                >
+                  <svg class="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                    <path
+                      stroke-linecap="round"
+                      stroke-linejoin="round"
+                      stroke-width="2"
+                      d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16"
+                    />
+                  </svg>
+                </button>
+              </div>
+            </div>
+
+            <button
+              type="button"
+              class="w-full rounded-lg border-2 border-dashed border-gray-300 px-4 py-2 text-gray-600 transition-colors hover:border-gray-400 hover:text-gray-700 dark:border-dark-500 dark:text-gray-400 dark:hover:border-dark-400 dark:hover:text-gray-300"
+              @click="addHeaderOverrideRow"
+            >
+              <svg class="mr-1 inline h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                <path
+                  stroke-linecap="round"
+                  stroke-linejoin="round"
+                  stroke-width="2"
+                  d="M12 4v16m8-8H4"
+                />
+              </svg>
+              {{ t('admin.accounts.headerOverride.addRow') }}
+            </button>
+
+            <div class="flex flex-wrap gap-2">
+              <button
+                type="button"
+                class="rounded-lg bg-primary-50 px-3 py-1 text-xs text-primary-700 transition-colors hover:bg-primary-100 dark:bg-primary-900/30 dark:text-primary-400 dark:hover:bg-primary-900/50"
+                @click="fillHeaderOverrideTemplate"
+              >
+                + {{ t('admin.accounts.headerOverride.fillTemplate') }}
+              </button>
+            </div>
+
+            <p class="text-xs text-gray-500 dark:text-gray-400">
+              {{ t('admin.accounts.headerOverride.emptyValueHint') }}
+            </p>
+          </div>
+          <p v-else class="text-xs text-gray-500 dark:text-gray-400">
+            {{ t('admin.accounts.headerOverride.bulkDisableHint') }}
+          </p>
+        </div>
+      </div>
+
       <!-- Proxy -->
       <div class="border-t border-gray-200 pt-4 dark:border-dark-600">
         <div class="mb-3 flex items-center justify-between">
@@ -1149,6 +1268,16 @@ import {
   buildModelMappingObject as buildModelMappingPayload,
   getPresetMappingsByPlatform
 } from '@/composables/useModelWhitelist'
+import {
+  buildHeaderOverridesObject,
+  getHeaderOverrideTemplate,
+  isHeaderOverridePlatform,
+  validateHeaderOverrideRows,
+  HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY,
+  HEADER_OVERRIDES_CREDENTIAL_KEY,
+  type HeaderOverrideRow
+} from '@/components/account/credentialsBuilder'
+import { createStableObjectKeyResolver } from '@/utils/stableObjectKey'
 import {
   OPENAI_WS_MODE_CTX_POOL,
   OPENAI_WS_MODE_OFF,
@@ -1217,6 +1346,16 @@ const allOpenAIAPIKey = computed(() => {
   )
 })
 
+// 是否全部为 anthropic/openai 平台的 apikey 账号（请求头覆写仅在此条件下显示）
+const allHeaderOverrideCapable = computed(() => {
+  return (
+    targetSelectedPlatforms.value.length > 0 &&
+    targetSelectedPlatforms.value.every(p => isHeaderOverridePlatform(p)) &&
+    targetSelectedTypes.value.length > 0 &&
+    targetSelectedTypes.value.every(t => t === 'apikey')
+  )
+})
+
 // 是否全部为 Anthropic OAuth/SetupToken（RPM 配置仅在此条件下显示）
 const allAnthropicOAuthOrSetupToken = computed(() => {
   return (
@@ -1253,6 +1392,7 @@ const enableBaseUrl = ref(false)
 const enableModelRestriction = ref(false)
 const enableCustomErrorCodes = ref(false)
 const enableInterceptWarmup = ref(false)
+const enableHeaderOverride = ref(false)
 const enableProxy = ref(false)
 const enableConcurrency = ref(false)
 const enableLoadFactor = ref(false)
@@ -1281,6 +1421,36 @@ const modelMappings = ref<ModelMapping[]>([])
 const selectedErrorCodes = ref<number[]>([])
 const customErrorCodeInput = ref<number | null>(null)
 const interceptWarmupRequests = ref(false)
+const headerOverrideEnabled = ref(false)
+const headerOverrideRows = ref<HeaderOverrideRow[]>([])
+const getHeaderOverrideRowKey = createStableObjectKeyResolver<HeaderOverrideRow>('bulk-header-override-row')
+
+const addHeaderOverrideRow = () => {
+  headerOverrideRows.value.push({ name: '', value: '' })
+}
+
+const removeHeaderOverrideRow = (index: number) => {
+  headerOverrideRows.value.splice(index, 1)
+}
+
+// 模板按钮：填入标准客户端请求头名称（值留空），跳过已存在的同名行。
+// 目标全为 openai 时用 Codex 模板，否则用 Claude Code 模板。
+const fillHeaderOverrideTemplate = () => {
+  const platform =
+    targetSelectedPlatforms.value.length === 1 && targetSelectedPlatforms.value[0] === 'openai'
+      ? 'openai'
+      : 'anthropic'
+  const existing = new Set(
+    headerOverrideRows.value.map((row) => row.name.trim().toLowerCase()).filter(Boolean)
+  )
+  const rows = headerOverrideRows.value.filter((row) => row.name.trim() || row.value.trim())
+  for (const row of getHeaderOverrideTemplate(platform)) {
+    if (!existing.has(row.name)) {
+      rows.push(row)
+    }
+  }
+  headerOverrideRows.value = rows
+}
 const proxyId = ref<number | null>(null)
 const concurrency = ref(1)
 const loadFactor = ref<number | null>(null)
@@ -1523,6 +1693,15 @@ const buildUpdatePayload = (): Record<string, unknown> | null => {
     credentialsChanged = true
   }
 
+  if (enableHeaderOverride.value) {
+    // 后端使用 JSONB || merge 语义：关闭时显式写入 false + 空对象以清除旧配置
+    credentials[HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY] = headerOverrideEnabled.value
+    credentials[HEADER_OVERRIDES_CREDENTIAL_KEY] = headerOverrideEnabled.value
+      ? buildHeaderOverridesObject(headerOverrideRows.value)
+      : {}
+    credentialsChanged = true
+  }
+
   if (enableOpenAIWSMode.value) {
     const extra = ensureExtra()
     extra.openai_oauth_responses_websockets_v2_mode = openaiOAuthResponsesWebSocketV2Mode.value
@@ -1651,6 +1830,7 @@ const handleSubmit = async () => {
     enableModelRestriction.value ||
     enableCustomErrorCodes.value ||
     enableInterceptWarmup.value ||
+    enableHeaderOverride.value ||
     enableProxy.value ||
     enableConcurrency.value ||
     enableLoadFactor.value ||
@@ -1672,6 +1852,14 @@ const handleSubmit = async () => {
     return
   }
 
+  if (enableHeaderOverride.value && headerOverrideEnabled.value) {
+    const headerError = validateHeaderOverrideRows(headerOverrideRows.value)
+    if (headerError) {
+      appStore.showError(t(`admin.accounts.headerOverride.${headerError}`))
+      return
+    }
+  }
+
   const built = buildUpdatePayload()
   if (!built) {
     appStore.showError(t('admin.accounts.bulkEdit.noFieldsSelected'))
@@ -1753,6 +1941,7 @@ watch(
       enableModelRestriction.value = false
       enableCustomErrorCodes.value = false
       enableInterceptWarmup.value = false
+      enableHeaderOverride.value = false
       enableProxy.value = false
       enableConcurrency.value = false
       enableLoadFactor.value = false
@@ -1778,6 +1967,8 @@ watch(
       selectedErrorCodes.value = []
       customErrorCodeInput.value = null
       interceptWarmupRequests.value = false
+      headerOverrideEnabled.value = false
+      headerOverrideRows.value = []
       proxyId.value = null
       concurrency.value = 1
       loadFactor.value = null
diff --git a/frontend/src/components/account/CreateAccountModal.vue b/frontend/src/components/account/CreateAccountModal.vue
index 3514153c82..a00b49cfa0 100644
--- a/frontend/src/components/account/CreateAccountModal.vue
+++ b/frontend/src/components/account/CreateAccountModal.vue
@@ -1468,6 +1468,110 @@
           </div>
         </div>
 
+        <!-- Header Override Section (anthropic/openai apikey only) -->
+        <div
+          v-if="isHeaderOverridePlatform(form.platform)"
+          class="border-t border-gray-200 pt-4 dark:border-dark-600"
+        >
+          <div class="mb-3 flex items-center justify-between">
+            <div>
+              <label class="input-label mb-0">{{ t('admin.accounts.headerOverride.title') }}</label>
+              <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
+                {{ t('admin.accounts.headerOverride.hint') }}
+              </p>
+            </div>
+            <button
+              type="button"
+              @click="headerOverrideEnabled = !headerOverrideEnabled"
+              :class="[
+                'relative inline-flex h-6 w-11 flex-shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors duration-200 ease-in-out focus:outline-none focus:ring-2 focus:ring-primary-500 focus:ring-offset-2',
+                headerOverrideEnabled ? 'bg-primary-600' : 'bg-gray-200 dark:bg-dark-600'
+              ]"
+            >
+              <span
+                :class="[
+                  'pointer-events-none inline-block h-5 w-5 transform rounded-full bg-white shadow ring-0 transition duration-200 ease-in-out',
+                  headerOverrideEnabled ? 'translate-x-5' : 'translate-x-0'
+                ]"
+              />
+            </button>
+          </div>
+
+          <div v-if="headerOverrideEnabled" class="space-y-3">
+            <div class="rounded-lg bg-blue-50 p-3 dark:bg-blue-900/20">
+              <p class="text-xs text-blue-700 dark:text-blue-400">
+                <Icon name="exclamationCircle" size="sm" class="mr-1 inline" :stroke-width="2" />
+                {{ t('admin.accounts.headerOverride.info') }}
+              </p>
+            </div>
+
+            <div v-if="headerOverrideRows.length > 0" class="space-y-2">
+              <div
+                v-for="(row, index) in headerOverrideRows"
+                :key="getHeaderOverrideRowKey(row)"
+                class="flex items-center gap-2"
+              >
+                <input
+                  v-model="row.name"
+                  type="text"
+                  class="input flex-1"
+                  :placeholder="t('admin.accounts.headerOverride.namePlaceholder')"
+                />
+                <input
+                  v-model="row.value"
+                  type="text"
+                  class="input flex-1"
+                  :placeholder="t('admin.accounts.headerOverride.valuePlaceholder')"
+                />
+                <button
+                  type="button"
+                  @click="removeHeaderOverrideRow(index)"
+                  class="rounded-lg p-2 text-red-500 transition-colors hover:bg-red-50 hover:text-red-600 dark:hover:bg-red-900/20"
+                >
+                  <svg class="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                    <path
+                      stroke-linecap="round"
+                      stroke-linejoin="round"
+                      stroke-width="2"
+                      d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16"
+                    />
+                  </svg>
+                </button>
+              </div>
+            </div>
+
+            <button
+              type="button"
+              @click="addHeaderOverrideRow"
+              class="w-full rounded-lg border-2 border-dashed border-gray-300 px-4 py-2 text-gray-600 transition-colors hover:border-gray-400 hover:text-gray-700 dark:border-dark-500 dark:text-gray-400 dark:hover:border-dark-400 dark:hover:text-gray-300"
+            >
+              <svg class="mr-1 inline h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                <path
+                  stroke-linecap="round"
+                  stroke-linejoin="round"
+                  stroke-width="2"
+                  d="M12 4v16m8-8H4"
+                />
+              </svg>
+              {{ t('admin.accounts.headerOverride.addRow') }}
+            </button>
+
+            <div class="flex flex-wrap gap-2">
+              <button
+                type="button"
+                @click="fillHeaderOverrideTemplate"
+                class="rounded-lg bg-primary-50 px-3 py-1 text-xs text-primary-700 transition-colors hover:bg-primary-100 dark:bg-primary-900/30 dark:text-primary-400 dark:hover:bg-primary-900/50"
+              >
+                + {{ t('admin.accounts.headerOverride.fillTemplate') }}
+              </button>
+            </div>
+
+            <p class="text-xs text-gray-500 dark:text-gray-400">
+              {{ t('admin.accounts.headerOverride.emptyValueHint') }}
+            </p>
+          </div>
+        </div>
+
       </div>
 
       <!-- Bedrock credentials (only for Anthropic Bedrock type) -->
@@ -3328,7 +3432,12 @@ import ModelWhitelistSelector from '@/components/account/ModelWhitelistSelector.
 import QuotaLimitCard from '@/components/account/QuotaLimitCard.vue'
 import {
   applyAntigravityProjectID,
-  applyInterceptWarmup
+  applyHeaderOverride,
+  applyInterceptWarmup,
+  getHeaderOverrideTemplate,
+  isHeaderOverridePlatform,
+  validateHeaderOverrideRows,
+  type HeaderOverrideRow
 } from '@/components/account/credentialsBuilder'
 import { formatDateTimeLocalInput, parseDateTimeLocalInput } from '@/utils/format'
 import { createStableObjectKeyResolver } from '@/utils/stableObjectKey'
@@ -3512,6 +3621,30 @@ function parsePoolModeRetryStatusCodes(input: string): number[] {
 const customErrorCodesEnabled = ref(false)
 const selectedErrorCodes = ref<number[]>([])
 const customErrorCodeInput = ref<number | null>(null)
+const headerOverrideEnabled = ref(false)
+const headerOverrideRows = ref<HeaderOverrideRow[]>([])
+
+const addHeaderOverrideRow = () => {
+  headerOverrideRows.value.push({ name: '', value: '' })
+}
+
+const removeHeaderOverrideRow = (index: number) => {
+  headerOverrideRows.value.splice(index, 1)
+}
+
+// 模板按钮：填入标准客户端请求头名称（值留空），跳过已存在的同名行
+const fillHeaderOverrideTemplate = () => {
+  const existing = new Set(
+    headerOverrideRows.value.map((row) => row.name.trim().toLowerCase()).filter(Boolean)
+  )
+  const rows = headerOverrideRows.value.filter((row) => row.name.trim() || row.value.trim())
+  for (const row of getHeaderOverrideTemplate(form.platform)) {
+    if (!existing.has(row.name)) {
+      rows.push(row)
+    }
+  }
+  headerOverrideRows.value = rows
+}
 const interceptWarmupRequests = ref(false)
 const autoPauseOnExpired = ref(true)
 const openaiPassthroughEnabled = ref(false)
@@ -3569,6 +3702,7 @@ const vertexServiceAccountDragActive = ref(false)
 const tempUnschedEnabled = ref(false)
 const tempUnschedRules = ref<TempUnschedRuleForm[]>([])
 const getModelMappingKey = createStableObjectKeyResolver<ModelMapping>('create-model-mapping')
+const getHeaderOverrideRowKey = createStableObjectKeyResolver<HeaderOverrideRow>('create-header-override-row')
 const getOpenAICompactModelMappingKey = createStableObjectKeyResolver<ModelMapping>('create-openai-compact-model-mapping')
 const getAntigravityModelMappingKey = createStableObjectKeyResolver<ModelMapping>('create-antigravity-model-mapping')
 const getTempUnschedRuleKey = createStableObjectKeyResolver<TempUnschedRuleForm>('create-temp-unsched-rule')
@@ -4359,6 +4493,8 @@ const resetForm = () => {
   customErrorCodesEnabled.value = false
   selectedErrorCodes.value = []
   customErrorCodeInput.value = null
+  headerOverrideEnabled.value = false
+  headerOverrideRows.value = []
   interceptWarmupRequests.value = false
   autoPauseOnExpired.value = true
   openaiPassthroughEnabled.value = false
@@ -4789,6 +4925,18 @@ const handleSubmit = async () => {
     credentials.custom_error_codes = [...selectedErrorCodes.value]
   }
 
+  // Add header override if enabled (anthropic/openai apikey only)
+  if (isHeaderOverridePlatform(form.platform)) {
+    if (headerOverrideEnabled.value) {
+      const headerError = validateHeaderOverrideRows(headerOverrideRows.value)
+      if (headerError) {
+        appStore.showError(t(`admin.accounts.headerOverride.${headerError}`))
+        return
+      }
+    }
+    applyHeaderOverride(credentials, headerOverrideEnabled.value, headerOverrideRows.value, 'create')
+  }
+
   applyInterceptWarmup(credentials, interceptWarmupRequests.value, 'create')
   if (!applyTempUnschedConfig(credentials)) {
     return
diff --git a/frontend/src/components/account/EditAccountModal.vue b/frontend/src/components/account/EditAccountModal.vue
index 3670f233e3..9b5ab82fc5 100644
--- a/frontend/src/components/account/EditAccountModal.vue
+++ b/frontend/src/components/account/EditAccountModal.vue
@@ -417,6 +417,110 @@
           </div>
         </div>
 
+        <!-- Header Override Section (anthropic/openai apikey only) -->
+        <div
+          v-if="isHeaderOverridePlatform(account.platform)"
+          class="border-t border-gray-200 pt-4 dark:border-dark-600"
+        >
+          <div class="mb-3 flex items-center justify-between">
+            <div>
+              <label class="input-label mb-0">{{ t('admin.accounts.headerOverride.title') }}</label>
+              <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
+                {{ t('admin.accounts.headerOverride.hint') }}
+              </p>
+            </div>
+            <button
+              type="button"
+              @click="headerOverrideEnabled = !headerOverrideEnabled"
+              :class="[
+                'relative inline-flex h-6 w-11 flex-shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors duration-200 ease-in-out focus:outline-none focus:ring-2 focus:ring-primary-500 focus:ring-offset-2',
+                headerOverrideEnabled ? 'bg-primary-600' : 'bg-gray-200 dark:bg-dark-600'
+              ]"
+            >
+              <span
+                :class="[
+                  'pointer-events-none inline-block h-5 w-5 transform rounded-full bg-white shadow ring-0 transition duration-200 ease-in-out',
+                  headerOverrideEnabled ? 'translate-x-5' : 'translate-x-0'
+                ]"
+              />
+            </button>
+          </div>
+
+          <div v-if="headerOverrideEnabled" class="space-y-3">
+            <div class="rounded-lg bg-blue-50 p-3 dark:bg-blue-900/20">
+              <p class="text-xs text-blue-700 dark:text-blue-400">
+                <Icon name="exclamationCircle" size="sm" class="mr-1 inline" :stroke-width="2" />
+                {{ t('admin.accounts.headerOverride.info') }}
+              </p>
+            </div>
+
+            <div v-if="headerOverrideRows.length > 0" class="space-y-2">
+              <div
+                v-for="(row, index) in headerOverrideRows"
+                :key="getHeaderOverrideRowKey(row)"
+                class="flex items-center gap-2"
+              >
+                <input
+                  v-model="row.name"
+                  type="text"
+                  class="input flex-1"
+                  :placeholder="t('admin.accounts.headerOverride.namePlaceholder')"
+                />
+                <input
+                  v-model="row.value"
+                  type="text"
+                  class="input flex-1"
+                  :placeholder="t('admin.accounts.headerOverride.valuePlaceholder')"
+                />
+                <button
+                  type="button"
+                  @click="removeHeaderOverrideRow(index)"
+                  class="rounded-lg p-2 text-red-500 transition-colors hover:bg-red-50 hover:text-red-600 dark:hover:bg-red-900/20"
+                >
+                  <svg class="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                    <path
+                      stroke-linecap="round"
+                      stroke-linejoin="round"
+                      stroke-width="2"
+                      d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16"
+                    />
+                  </svg>
+                </button>
+              </div>
+            </div>
+
+            <button
+              type="button"
+              @click="addHeaderOverrideRow"
+              class="w-full rounded-lg border-2 border-dashed border-gray-300 px-4 py-2 text-gray-600 transition-colors hover:border-gray-400 hover:text-gray-700 dark:border-dark-500 dark:text-gray-400 dark:hover:border-dark-400 dark:hover:text-gray-300"
+            >
+              <svg class="mr-1 inline h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                <path
+                  stroke-linecap="round"
+                  stroke-linejoin="round"
+                  stroke-width="2"
+                  d="M12 4v16m8-8H4"
+                />
+              </svg>
+              {{ t('admin.accounts.headerOverride.addRow') }}
+            </button>
+
+            <div class="flex flex-wrap gap-2">
+              <button
+                type="button"
+                @click="fillHeaderOverrideTemplate"
+                class="rounded-lg bg-primary-50 px-3 py-1 text-xs text-primary-700 transition-colors hover:bg-primary-100 dark:bg-primary-900/30 dark:text-primary-400 dark:hover:bg-primary-900/50"
+              >
+                + {{ t('admin.accounts.headerOverride.fillTemplate') }}
+              </button>
+            </div>
+
+            <p class="text-xs text-gray-500 dark:text-gray-400">
+              {{ t('admin.accounts.headerOverride.emptyValueHint') }}
+            </p>
+          </div>
+        </div>
+
       </div>
 
       <!-- OpenAI/Grok OAuth Model Mapping (OAuth 类型没有 apikey 容器，需要独立的模型映射区域) -->
@@ -2433,7 +2537,15 @@ import ModelWhitelistSelector from '@/components/account/ModelWhitelistSelector.
 import QuotaLimitCard from '@/components/account/QuotaLimitCard.vue'
 import {
   applyAntigravityProjectID,
-  applyInterceptWarmup
+  applyHeaderOverride,
+  applyInterceptWarmup,
+  getHeaderOverrideTemplate,
+  isHeaderOverridePlatform,
+  splitHeaderOverridesObject,
+  validateHeaderOverrideRows,
+  HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY,
+  HEADER_OVERRIDES_CREDENTIAL_KEY,
+  type HeaderOverrideRow
 } from '@/components/account/credentialsBuilder'
 import { formatDateTime, formatDateTimeLocalInput, parseDateTimeLocalInput } from '@/utils/format'
 import { createStableObjectKeyResolver } from '@/utils/stableObjectKey'
@@ -2564,6 +2676,30 @@ function formatPoolModeRetryStatusCodes(value: unknown): string {
 const customErrorCodesEnabled = ref(false)
 const selectedErrorCodes = ref<number[]>([])
 const customErrorCodeInput = ref<number | null>(null)
+const headerOverrideEnabled = ref(false)
+const headerOverrideRows = ref<HeaderOverrideRow[]>([])
+
+const addHeaderOverrideRow = () => {
+  headerOverrideRows.value.push({ name: '', value: '' })
+}
+
+const removeHeaderOverrideRow = (index: number) => {
+  headerOverrideRows.value.splice(index, 1)
+}
+
+// 模板按钮：填入标准客户端请求头名称（值留空），跳过已存在的同名行
+const fillHeaderOverrideTemplate = () => {
+  const existing = new Set(
+    headerOverrideRows.value.map((row) => row.name.trim().toLowerCase()).filter(Boolean)
+  )
+  const rows = headerOverrideRows.value.filter((row) => row.name.trim() || row.value.trim())
+  for (const row of getHeaderOverrideTemplate(props.account?.platform || '')) {
+    if (!existing.has(row.name)) {
+      rows.push(row)
+    }
+  }
+  headerOverrideRows.value = rows
+}
 const interceptWarmupRequests = ref(false)
 const autoPauseOnExpired = ref(false)
 const autoPause5hThreshold = ref<number | null>(null)
@@ -2580,6 +2716,7 @@ const isSyncingAntigravityUpstream = ref(false)
 const tempUnschedEnabled = ref(false)
 const tempUnschedRules = ref<TempUnschedRuleForm[]>([])
 const getModelMappingKey = createStableObjectKeyResolver<ModelMapping>('edit-model-mapping')
+const getHeaderOverrideRowKey = createStableObjectKeyResolver<HeaderOverrideRow>('edit-header-override-row')
 const getOpenAICompactModelMappingKey = createStableObjectKeyResolver<ModelMapping>('edit-openai-compact-model-mapping')
 const getAntigravityModelMappingKey = createStableObjectKeyResolver<ModelMapping>('edit-antigravity-model-mapping')
 const getTempUnschedRuleKey = createStableObjectKeyResolver<TempUnschedRuleForm>('edit-temp-unsched-rule')
@@ -3186,6 +3323,10 @@ const syncFormFromAccount = (newAccount: Account | null) => {
 
   loadTempUnschedRules(credentials)
 
+  // Reset header override state (loaded below only for apikey accounts)
+  headerOverrideEnabled.value = false
+  headerOverrideRows.value = []
+
   // Initialize API Key fields for apikey type
   if (newAccount.type === 'apikey' && newAccount.credentials) {
     const credentials = newAccount.credentials as Record<string, unknown>
@@ -3215,6 +3356,14 @@ const syncFormFromAccount = (newAccount: Account | null) => {
     } else {
       selectedErrorCodes.value = []
     }
+
+    // Load header override (anthropic/openai apikey only)
+    headerOverrideEnabled.value =
+      isHeaderOverridePlatform(newAccount.platform) &&
+      credentials[HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY] === true
+    headerOverrideRows.value = splitHeaderOverridesObject(
+      credentials[HEADER_OVERRIDES_CREDENTIAL_KEY]
+    )
   } else if (newAccount.type === 'bedrock' && newAccount.credentials) {
     const bedrockCreds = newAccount.credentials as Record<string, unknown>
     const authMode = (bedrockCreds.auth_mode as string) || 'sigv4'
@@ -3850,6 +3999,18 @@ const handleSubmit = async () => {
         delete newCredentials.custom_error_codes
       }
 
+      // Add header override if enabled (anthropic/openai apikey only)
+      if (isHeaderOverridePlatform(props.account.platform)) {
+        if (headerOverrideEnabled.value) {
+          const headerError = validateHeaderOverrideRows(headerOverrideRows.value)
+          if (headerError) {
+            appStore.showError(t(`admin.accounts.headerOverride.${headerError}`))
+            return
+          }
+        }
+        applyHeaderOverride(newCredentials, headerOverrideEnabled.value, headerOverrideRows.value, 'edit')
+      }
+
       // Add intercept warmup requests setting
       applyInterceptWarmup(newCredentials, interceptWarmupRequests.value, 'edit')
       if (!applyTempUnschedConfig(newCredentials)) {
diff --git a/frontend/src/components/account/__tests__/credentialsBuilder.spec.ts b/frontend/src/components/account/__tests__/credentialsBuilder.spec.ts
index 665b1732e7..cbad111f45 100644
--- a/frontend/src/components/account/__tests__/credentialsBuilder.spec.ts
+++ b/frontend/src/components/account/__tests__/credentialsBuilder.spec.ts
@@ -1,8 +1,16 @@
 import { describe, it, expect } from 'vitest'
 import {
   ANTIGRAVITY_PROJECT_ID_CREDENTIAL_KEY,
+  HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY,
+  HEADER_OVERRIDES_CREDENTIAL_KEY,
   applyAntigravityProjectID,
-  applyInterceptWarmup
+  applyHeaderOverride,
+  applyInterceptWarmup,
+  buildHeaderOverridesObject,
+  getHeaderOverrideTemplate,
+  isHeaderOverridePlatform,
+  splitHeaderOverridesObject,
+  validateHeaderOverrideRows
 } from '../credentialsBuilder'
 
 describe('applyInterceptWarmup', () => {
@@ -82,3 +90,185 @@ describe('applyAntigravityProjectID', () => {
     expect(creds[ANTIGRAVITY_PROJECT_ID_CREDENTIAL_KEY]).toBe('configured-project')
   })
 })
+
+describe('isHeaderOverridePlatform', () => {
+  it('only anthropic and openai are supported', () => {
+    expect(isHeaderOverridePlatform('anthropic')).toBe(true)
+    expect(isHeaderOverridePlatform('openai')).toBe(true)
+    expect(isHeaderOverridePlatform('gemini')).toBe(false)
+    expect(isHeaderOverridePlatform('grok')).toBe(false)
+    expect(isHeaderOverridePlatform('antigravity')).toBe(false)
+    expect(isHeaderOverridePlatform('')).toBe(false)
+  })
+})
+
+describe('validateHeaderOverrideRows', () => {
+  it('accepts valid rows and empty placeholder rows', () => {
+    expect(
+      validateHeaderOverrideRows([
+        { name: 'user-agent', value: 'my-agent/1.0' },
+        { name: 'x-app', value: '' },
+        { name: '', value: '' }
+      ])
+    ).toBeNull()
+  })
+
+  it('rejects empty name with non-empty value', () => {
+    expect(validateHeaderOverrideRows([{ name: '', value: 'v' }])).toBe('invalidName')
+  })
+
+  it('rejects invalid header names', () => {
+    expect(validateHeaderOverrideRows([{ name: 'bad name', value: '' }])).toBe('invalidName')
+    expect(validateHeaderOverrideRows([{ name: 'bad:name', value: '' }])).toBe('invalidName')
+    expect(validateHeaderOverrideRows([{ name: '名称', value: '' }])).toBe('invalidName')
+  })
+
+  it('rejects blocked header names case-insensitively', () => {
+    expect(validateHeaderOverrideRows([{ name: 'Authorization', value: '' }])).toBe('blockedName')
+    expect(validateHeaderOverrideRows([{ name: 'X-Api-Key', value: '' }])).toBe('blockedName')
+    expect(validateHeaderOverrideRows([{ name: 'host', value: '' }])).toBe('blockedName')
+    expect(validateHeaderOverrideRows([{ name: 'Content-Length', value: '' }])).toBe('blockedName')
+  })
+
+  it('rejects duplicate names case-insensitively', () => {
+    expect(
+      validateHeaderOverrideRows([
+        { name: 'User-Agent', value: 'a' },
+        { name: 'user-agent', value: 'b' }
+      ])
+    ).toBe('duplicateName')
+  })
+})
+
+describe('buildHeaderOverridesObject / splitHeaderOverridesObject', () => {
+  it('lowercases names, trims values and drops empty-name rows', () => {
+    expect(
+      buildHeaderOverridesObject([
+        { name: ' User-Agent ', value: ' my-agent ' },
+        { name: 'X-App', value: '' },
+        { name: '', value: 'ignored' }
+      ])
+    ).toEqual({ 'user-agent': 'my-agent', 'x-app': '' })
+  })
+
+  it('splits an object into sorted rows and ignores non-string values', () => {
+    expect(
+      splitHeaderOverridesObject({ 'x-app': 'cli', 'user-agent': 'ua', bogus: 42 })
+    ).toEqual([
+      { name: 'user-agent', value: 'ua' },
+      { name: 'x-app', value: 'cli' }
+    ])
+    expect(splitHeaderOverridesObject(null)).toEqual([])
+    expect(splitHeaderOverridesObject(['a'])).toEqual([])
+    expect(splitHeaderOverridesObject('str')).toEqual([])
+  })
+
+  it('roundtrips through build and split', () => {
+    const rows = [
+      { name: 'user-agent', value: 'ua' },
+      { name: 'x-app', value: 'cli' }
+    ]
+    expect(splitHeaderOverridesObject(buildHeaderOverridesObject(rows))).toEqual(rows)
+  })
+})
+
+describe('getHeaderOverrideTemplate', () => {
+  it('returns Claude Code CLI headers with empty values for anthropic', () => {
+    const rows = getHeaderOverrideTemplate('anthropic')
+    expect(rows.every((r) => r.value === '')).toBe(true)
+    const names = rows.map((r) => r.name)
+    expect(names).toContain('user-agent')
+    expect(names).toContain('x-app')
+    expect(names).toContain('anthropic-beta')
+    expect(names).toContain('x-stainless-lang')
+    expect(validateHeaderOverrideRows(rows)).toBeNull()
+  })
+
+  it('returns Codex CLI headers with empty values for openai', () => {
+    const rows = getHeaderOverrideTemplate('openai')
+    expect(rows.every((r) => r.value === '')).toBe(true)
+    const names = rows.map((r) => r.name)
+    expect(names).toContain('user-agent')
+    expect(names).toContain('originator')
+    expect(names).toContain('openai-beta')
+    expect(validateHeaderOverrideRows(rows)).toBeNull()
+  })
+})
+
+describe('applyHeaderOverride', () => {
+  it('create + enabled: writes enabled flag and overrides object', () => {
+    const creds: Record<string, unknown> = { api_key: 'sk' }
+    applyHeaderOverride(creds, true, [{ name: 'User-Agent', value: 'ua' }], 'create')
+    expect(creds[HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY]).toBe(true)
+    expect(creds[HEADER_OVERRIDES_CREDENTIAL_KEY]).toEqual({ 'user-agent': 'ua' })
+  })
+
+  it('create + disabled: does not add fields', () => {
+    const creds: Record<string, unknown> = { api_key: 'sk' }
+    applyHeaderOverride(creds, false, [{ name: 'user-agent', value: 'ua' }], 'create')
+    expect(HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY in creds).toBe(false)
+    expect(HEADER_OVERRIDES_CREDENTIAL_KEY in creds).toBe(false)
+  })
+
+  it('edit + disabled: deletes existing fields', () => {
+    const creds: Record<string, unknown> = {
+      api_key: 'sk',
+      [HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY]: true,
+      [HEADER_OVERRIDES_CREDENTIAL_KEY]: { 'user-agent': 'ua' }
+    }
+    applyHeaderOverride(creds, false, [], 'edit')
+    expect(HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY in creds).toBe(false)
+    expect(HEADER_OVERRIDES_CREDENTIAL_KEY in creds).toBe(false)
+    expect(creds.api_key).toBe('sk')
+  })
+
+  it('edit + enabled: replaces overrides object wholesale', () => {
+    const creds: Record<string, unknown> = {
+      [HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY]: true,
+      [HEADER_OVERRIDES_CREDENTIAL_KEY]: { 'x-old': 'old' }
+    }
+    applyHeaderOverride(creds, true, [{ name: 'x-new', value: 'new' }], 'edit')
+    expect(creds[HEADER_OVERRIDES_CREDENTIAL_KEY]).toEqual({ 'x-new': 'new' })
+  })
+})
+
+describe('validateHeaderOverrideRows value/entry limits', () => {
+  it('rejects websocket handshake headers', () => {
+    expect(validateHeaderOverrideRows([{ name: 'Sec-WebSocket-Key', value: '' }])).toBe(
+      'blockedName'
+    )
+  })
+
+  it('rejects control characters in values', () => {
+    expect(validateHeaderOverrideRows([{ name: 'x-app', value: 'a\x0bb' }])).toBe('invalidValue')
+  })
+
+  it('rejects oversized values', () => {
+    expect(validateHeaderOverrideRows([{ name: 'x-app', value: 'a'.repeat(8193) }])).toBe(
+      'invalidValue'
+    )
+  })
+
+  it('rejects too many entries', () => {
+    const rows = Array.from({ length: 65 }, (_, i) => ({ name: `x-h-${i}`, value: 'v' }))
+    expect(validateHeaderOverrideRows(rows)).toBe('tooManyEntries')
+  })
+})
+
+describe('validateHeaderOverrideRows session isolation headers', () => {
+  it('rejects per-request session headers', () => {
+    expect(validateHeaderOverrideRows([{ name: 'session_id', value: '' }])).toBe('blockedName')
+    expect(validateHeaderOverrideRows([{ name: 'Conversation_ID', value: '' }])).toBe('blockedName')
+    expect(validateHeaderOverrideRows([{ name: 'x-codex-turn-state', value: '' }])).toBe(
+      'blockedName'
+    )
+  })
+
+  it('allows tab inside value', () => {
+    expect(validateHeaderOverrideRows([{ name: 'x-app', value: 'a\tb' }])).toBeNull()
+  })
+
+  it('rejects oversized names', () => {
+    expect(validateHeaderOverrideRows([{ name: 'x'.repeat(201), value: 'v' }])).toBe('invalidName')
+  })
+})
diff --git a/frontend/src/components/account/credentialsBuilder.ts b/frontend/src/components/account/credentialsBuilder.ts
index f138976519..9e175a2712 100644
--- a/frontend/src/components/account/credentialsBuilder.ts
+++ b/frontend/src/components/account/credentialsBuilder.ts
@@ -24,3 +24,170 @@ export function applyAntigravityProjectID(
     delete credentials[ANTIGRAVITY_PROJECT_ID_CREDENTIAL_KEY]
   }
 }
+
+// ========== 请求头覆写（仅 anthropic/openai 平台的 api_key 账号） ==========
+
+export const HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY = 'header_override_enabled'
+export const HEADER_OVERRIDES_CREDENTIAL_KEY = 'header_overrides'
+
+export interface HeaderOverrideRow {
+  name: string
+  value: string
+}
+
+/** 请求头覆写支持的平台（与后端 IsHeaderOverrideEligible 保持一致） */
+export function isHeaderOverridePlatform(platform: string): boolean {
+  return platform === 'anthropic' || platform === 'openai'
+}
+
+/** 禁止覆写的请求头（与后端 headerOverrideBlockedNames 保持一致） */
+const HEADER_OVERRIDE_BLOCKED_NAMES = new Set([
+  'host',
+  'content-length',
+  'transfer-encoding',
+  'connection',
+  'keep-alive',
+  'proxy-authenticate',
+  'proxy-authorization',
+  'proxy-connection',
+  'te',
+  'trailer',
+  'upgrade',
+  'authorization',
+  'x-api-key',
+  'accept-encoding',
+  'sec-websocket-key',
+  'sec-websocket-version',
+  'sec-websocket-extensions',
+  'sec-websocket-protocol',
+  'sec-websocket-accept',
+  'session_id',
+  'conversation_id',
+  'x-codex-turn-state',
+  'x-codex-turn-metadata',
+  'chatgpt-account-id'
+])
+
+/** RFC 7230 token：合法的 HTTP header 名称字符集 */
+const HEADER_NAME_PATTERN = /^[!#$%&'*+\-.^_`|~0-9A-Za-z]+$/
+
+export function isValidHeaderOverrideName(name: string): boolean {
+  return HEADER_NAME_PATTERN.test(name)
+}
+
+export function isBlockedHeaderOverrideName(name: string): boolean {
+  return HEADER_OVERRIDE_BLOCKED_NAMES.has(name.trim().toLowerCase())
+}
+
+/** 模板：Claude Code CLI 标准客户端请求头（值留空由管理员填写） */
+const ANTHROPIC_HEADER_OVERRIDE_TEMPLATE = [
+  'user-agent',
+  'x-app',
+  'anthropic-beta',
+  'anthropic-version',
+  'anthropic-dangerous-direct-browser-access',
+  'x-stainless-lang',
+  'x-stainless-package-version',
+  'x-stainless-os',
+  'x-stainless-arch',
+  'x-stainless-runtime',
+  'x-stainless-runtime-version',
+  'x-stainless-retry-count',
+  'x-stainless-timeout'
+]
+
+/** 模板：Codex CLI 标准客户端请求头（值留空由管理员填写） */
+const OPENAI_HEADER_OVERRIDE_TEMPLATE = [
+  'user-agent',
+  'originator',
+  'openai-beta',
+  'version',
+  'accept',
+  'accept-language'
+]
+
+export function getHeaderOverrideTemplate(platform: string): HeaderOverrideRow[] {
+  const names =
+    platform === 'openai' ? OPENAI_HEADER_OVERRIDE_TEMPLATE : ANTHROPIC_HEADER_OVERRIDE_TEMPLATE
+  return names.map((name) => ({ name, value: '' }))
+}
+
+/** 与后端 maxHeaderOverride* 常量保持一致 */
+const HEADER_OVERRIDE_MAX_ENTRIES = 64
+const HEADER_OVERRIDE_MAX_NAME_LENGTH = 200
+const HEADER_OVERRIDE_MAX_VALUE_LENGTH = 8192
+
+/** header value 不允许包含控制字符（与后端 httpguts.ValidHeaderFieldValue 对齐） */
+// eslint-disable-next-line no-control-regex
+const HEADER_VALUE_INVALID_PATTERN = /[\x00-\x08\x0a-\x1f\x7f]/
+
+/**
+ * 校验请求头覆写行，返回首个错误的 i18n key（无错误返回 null）。
+ * 名称为空但值非空 → invalidName；名称非法 → invalidName；
+ * 禁止覆写 → blockedName；大小写不敏感重名 → duplicateName；
+ * 值含控制字符或超长 → invalidValue；条目过多 → tooManyEntries。
+ */
+export function validateHeaderOverrideRows(
+  rows: HeaderOverrideRow[]
+): 'invalidName' | 'blockedName' | 'duplicateName' | 'invalidValue' | 'tooManyEntries' | null {
+  const seen = new Set<string>()
+  for (const row of rows) {
+    const name = row.name.trim()
+    const value = row.value.trim()
+    if (!name) {
+      if (value) return 'invalidName'
+      continue
+    }
+    if (!isValidHeaderOverrideName(name) || name.length > HEADER_OVERRIDE_MAX_NAME_LENGTH) {
+      return 'invalidName'
+    }
+    const lower = name.toLowerCase()
+    if (HEADER_OVERRIDE_BLOCKED_NAMES.has(lower)) return 'blockedName'
+    if (seen.has(lower)) return 'duplicateName'
+    if (HEADER_VALUE_INVALID_PATTERN.test(value) || value.length > HEADER_OVERRIDE_MAX_VALUE_LENGTH) {
+      return 'invalidValue'
+    }
+    seen.add(lower)
+  }
+  if (seen.size > HEADER_OVERRIDE_MAX_ENTRIES) return 'tooManyEntries'
+  return null
+}
+
+/** 行数组 → credentials 存储对象（名称小写化，丢弃空行） */
+export function buildHeaderOverridesObject(rows: HeaderOverrideRow[]): Record<string, string> {
+  const result: Record<string, string> = {}
+  for (const row of rows) {
+    const name = row.name.trim().toLowerCase()
+    if (!name) continue
+    result[name] = row.value.trim()
+  }
+  return result
+}
+
+/** credentials 存储对象 → 行数组（按名称排序保证稳定展示） */
+export function splitHeaderOverridesObject(record: unknown): HeaderOverrideRow[] {
+  if (!record || typeof record !== 'object' || Array.isArray(record)) return []
+  return Object.entries(record as Record<string, unknown>)
+    .filter(([, value]) => typeof value === 'string')
+    .map(([name, value]) => ({ name, value: value as string }))
+    .sort((a, b) => a.name.localeCompare(b.name))
+}
+
+/**
+ * 将请求头覆写写入 credentials。
+ * create 模式：关闭时不写入任何字段；edit 模式：关闭时删除字段（全量替换语义）。
+ */
+export function applyHeaderOverride(
+  credentials: Record<string, unknown>,
+  enabled: boolean,
+  rows: HeaderOverrideRow[],
+  mode: 'create' | 'edit'
+): void {
+  if (enabled) {
+    credentials[HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY] = true
+    credentials[HEADER_OVERRIDES_CREDENTIAL_KEY] = buildHeaderOverridesObject(rows)
+  } else if (mode === 'edit') {
+    delete credentials[HEADER_OVERRIDE_ENABLED_CREDENTIAL_KEY]
+    delete credentials[HEADER_OVERRIDES_CREDENTIAL_KEY]
+  }
+}
diff --git a/frontend/src/i18n/locales/en.ts b/frontend/src/i18n/locales/en.ts
index 749d2dcbcd..6e5aa18b28 100644
--- a/frontend/src/i18n/locales/en.ts
+++ b/frontend/src/i18n/locales/en.ts
@@ -3674,6 +3674,22 @@ export default {
       interceptWarmupRequests: 'Intercept Warmup Requests',
       interceptWarmupRequestsDesc:
         'When enabled, warmup requests like title generation will return mock responses without consuming upstream tokens',
+      headerOverride: {
+        title: 'Header Override',
+        hint: 'Override same-named request headers on forwarding (case-insensitive)',
+        info: 'Applies to outbound requests of this account only: configured headers override client/gateway-generated headers of the same name before forwarding. Auth headers (authorization, x-api-key) and connection-control headers cannot be overridden.',
+        namePlaceholder: 'Header name (e.g. user-agent)',
+        valuePlaceholder: 'Override value (leave empty to skip)',
+        addRow: 'Add Header',
+        fillTemplate: 'Fill Template',
+        emptyValueHint: 'Rows with an empty value are placeholders and do not override anything.',
+        bulkDisableHint: 'Saving will disable header override and clear existing configuration on the selected accounts.',
+        invalidName: 'Invalid header name (only letters, digits and !#$%&\'*+-.^_`|~ are allowed)',
+        blockedName: 'This header cannot be overridden (auth and connection-control headers are managed by the system)',
+        duplicateName: 'Duplicate header name (matching is case-insensitive)',
+        invalidValue: 'Invalid header value (control characters are not allowed; max length 8192)',
+        tooManyEntries: 'Too many header override entries (max 64)'
+      },
       autoPauseOnExpired: 'Auto Pause On Expired',
       autoPauseOnExpiredDesc: 'When enabled, the account will auto pause scheduling after it expires',
 	  autoPause5hThreshold: '5h Usage Threshold (%)',
diff --git a/frontend/src/i18n/locales/zh.ts b/frontend/src/i18n/locales/zh.ts
index a0b1337796..3ec15e2ec6 100644
--- a/frontend/src/i18n/locales/zh.ts
+++ b/frontend/src/i18n/locales/zh.ts
@@ -3842,6 +3842,22 @@ export default {
       errorCodeExists: '该错误码已被选中',
       interceptWarmupRequests: '拦截预热请求',
       interceptWarmupRequestsDesc: '启用后，标题生成等预热请求将返回 mock 响应，不消耗上游 token',
+      headerOverride: {
+        title: '请求头覆写',
+        hint: '转发时用配置值覆盖同名请求头（不区分大小写）',
+        info: '仅对本账号的出站请求生效：配置的请求头会在转发前覆盖客户端/网关生成的同名头。认证头（authorization、x-api-key）与连接控制头不允许覆写。',
+        namePlaceholder: '请求头名称（如 user-agent）',
+        valuePlaceholder: '覆写值（留空表示不覆写）',
+        addRow: '添加请求头',
+        fillTemplate: '填入模板',
+        emptyValueHint: '值留空的行不会参与覆盖，仅作为待填写的占位。',
+        bulkDisableHint: '保存后将关闭所选账号的请求头覆写并清空已有配置。',
+        invalidName: '请求头名称格式不正确（仅允许字母、数字和 !#$%&\'*+-.^_`|~ 字符）',
+        blockedName: '该请求头不允许覆写（认证头与连接控制头由系统管理）',
+        duplicateName: '存在重复的请求头名称（匹配不区分大小写）',
+        invalidValue: '请求头值不合法（不允许控制字符，长度不超过 8192）',
+        tooManyEntries: '请求头覆写条目过多（最多 64 条）'
+      },
       autoPauseOnExpired: '过期自动暂停调度',
       autoPauseOnExpiredDesc: '启用后，账号过期将自动暂停调度',
 	  autoPause5hThreshold: '5h 用量阈值(%)',