fix: gpt->claude格式转换对齐effort映射和fast

backend/internal/service/gateway_beta_test.go

@@ -148,6 +148,32 @@ func TestBuildBetaTokenSet(t *testing.T) {
 	require.Empty(t, empty)
 }
 
+func TestContainsBetaToken(t *testing.T) {
+	tests := []struct {
+		name   string
+		header string
+		token  string
+		want   bool
+	}{
+		{"present in middle", "oauth-2025-04-20,fast-mode-2026-02-01,interleaved-thinking-2025-05-14", "fast-mode-2026-02-01", true},
+		{"present at start", "fast-mode-2026-02-01,oauth-2025-04-20", "fast-mode-2026-02-01", true},
+		{"present at end", "oauth-2025-04-20,fast-mode-2026-02-01", "fast-mode-2026-02-01", true},
+		{"only token", "fast-mode-2026-02-01", "fast-mode-2026-02-01", true},
+		{"not present", "oauth-2025-04-20,interleaved-thinking-2025-05-14", "fast-mode-2026-02-01", false},
+		{"with spaces", "oauth-2025-04-20, fast-mode-2026-02-01 , interleaved-thinking-2025-05-14", "fast-mode-2026-02-01", true},
+		{"empty header", "", "fast-mode-2026-02-01", false},
+		{"empty token", "fast-mode-2026-02-01", "", false},
+		{"partial match", "fast-mode-2026-02-01-extra", "fast-mode-2026-02-01", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := containsBetaToken(tt.header, tt.token)
+			require.Equal(t, tt.want, got)
+		})
+	}
+}
+
 func TestStripBetaTokensWithSet_EmptyDropSet(t *testing.T) {
 	header := "oauth-2025-04-20,interleaved-thinking-2025-05-14"
 	got := stripBetaTokensWithSet(header, map[string]struct{}{})

backend/internal/service/gateway_service.go

@@ -5341,6 +5341,19 @@ func droppedBetaSet(extra ...string) map[string]struct{} {
 	return m
 }
 
+// containsBetaToken checks if a comma-separated header value contains the given token.
+func containsBetaToken(header, token string) bool {
+	if header == "" || token == "" {
+		return false
+	}
+	for _, p := range strings.Split(header, ",") {
+		if strings.TrimSpace(p) == token {
+			return true
+		}
+	}
+	return false
+}
+
 func buildBetaTokenSet(tokens []string) map[string]struct{} {
 	m := make(map[string]struct{}, len(tokens))
 	for _, t := range tokens {

backend/internal/service/openai_gateway_messages.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/pkg/apicompat"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/claude"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
 	"github.com/Wei-Shaw/sub2api/internal/util/responseheaders"
 	"github.com/gin-gonic/gin"
@@ -46,6 +47,11 @@ func (s *OpenAIGatewayService) ForwardAsAnthropic(
 		return nil, fmt.Errorf("convert anthropic to responses: %w", err)
 	}
 
+	// 2b. Handle BetaFastMode → service_tier: "priority"
+	if containsBetaToken(c.GetHeader("anthropic-beta"), claude.BetaFastMode) {
+		responsesReq.ServiceTier = "priority"
+	}
+
 	// 3. Model mapping
 	mappedModel := account.GetMappedModel(originalModel)
 	// 分组级降级：账号未映射时使用分组默认映射模型
@@ -94,6 +100,12 @@ func (s *OpenAIGatewayService) ForwardAsAnthropic(
 		return nil, fmt.Errorf("build upstream request: %w", err)
 	}
 
+	// Override session_id with a deterministic UUID derived from the sticky
+	// session key (buildUpstreamRequest may have set it to the raw value).
+	if promptCacheKey != "" {
+		upstreamReq.Header.Set("session_id", generateSessionUUID(promptCacheKey))
+	}
+
 	// 7. Send request
 	proxyURL := ""
 	if account.Proxy != nil {
@@ -160,6 +172,18 @@ func (s *OpenAIGatewayService) ForwardAsAnthropic(
 		result, handleErr = s.handleAnthropicNonStreamingResponse(resp, c, originalModel, mappedModel, startTime)
 	}
 
+	// Propagate ServiceTier and ReasoningEffort to result for billing
+	if handleErr == nil && result != nil {
+		if responsesReq.ServiceTier != "" {
+			st := responsesReq.ServiceTier
+			result.ServiceTier = &st
+		}
+		if responsesReq.Reasoning != nil && responsesReq.Reasoning.Effort != "" {
+			re := responsesReq.Reasoning.Effort
+			result.ReasoningEffort = &re
+		}
+	}
+
 	// Extract and save Codex usage snapshot from response headers (for OAuth accounts)
 	if handleErr == nil && account.Type == AccountTypeOAuth {
 		if snapshot := ParseCodexRateLimitHeaders(resp.Header); snapshot != nil {