Merge pull request #7526 from HuntercodeT/fix/passthrough-model-discovery-merge

fix(gateway): let OpenAI passthrough accounts supplement model discovery instead of hiding mapped models

backend/internal/handler/gateway_models_test.go

@@ -287,6 +287,18 @@ func TestGatewayModels_UnmappedOpenAIAccountsSupplementMappedModels(t *testing.T
 			accounts: accounts[1:],
 			want:     []string{sparkModel, alias},
 		},
+		{
+			// A passthrough account with a stale mapping behaves like an unmapped
+			// one: it adds the defaults but never its own mapping keys, and it no
+			// longer hides the aliases declared on ordinary accounts.
+			name: "passthrough account contributes defaults without hiding mapped aliases",
+			accounts: append([]service.Account{{
+				ID: 5, Platform: service.PlatformOpenAI, Type: service.AccountTypeOAuth,
+				Credentials: map[string]any{"model_mapping": map[string]any{"stale-model": "stale-model"}},
+				Extra:       map[string]any{"openai_passthrough": true},
+			}}, accounts[1:]...),
+			want: append(openai.DefaultModelIDs(), alias),
+		},
 		{
 			name:     "unmapped accounts from another platform do not add defaults",
 			accounts: append([]service.Account{{ID: 4, Platform: service.PlatformAnthropic}}, accounts[1:]...),

backend/internal/service/gateway_hotpath_optimization_test.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/ctxkey"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/openai"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/usagestats"
 	gocache "github.com/patrickmn/go-cache"
 	"github.com/stretchr/testify/require"
@@ -670,7 +671,9 @@ func TestGetAvailableModels_OpenAIPassthroughUsesDefaultFallback(t *testing.T) {
 			want: nil,
 		},
 		{
-			name: "passthrough wins over ordinary account mapping",
+			// The passthrough account serves the default set (its stale mapping is
+			// ignored), while the ordinary account's mapping still reaches the list.
+			name: "passthrough contributes defaults alongside ordinary account mapping",
 			accounts: []Account{
 				{
 					ID:          2,
@@ -684,7 +687,7 @@ func TestGetAvailableModels_OpenAIPassthroughUsesDefaultFallback(t *testing.T) {
 					Extra:       map[string]any{"openai_passthrough": true},
 				},
 			},
-			want: nil,
+			want: dedupeAndSortModelIDs(append([]string{"configured-model"}, openai.DefaultModelIDs()...)),
 		},
 		{
 			name: "ordinary accounts preserve mapped whitelist",
@@ -708,7 +711,9 @@ func TestGetAvailableModels_OpenAIPassthroughUsesDefaultFallback(t *testing.T) {
 				modelsListCacheTTL: time.Minute,
 			}
 
-			require.Equal(t, tt.want, svc.GetAvailableModels(context.Background(), &groupID, PlatformOpenAI))
+			got := svc.GetAvailableModels(context.Background(), &groupID, PlatformOpenAI)
+			require.Equal(t, tt.want, got)
+			require.NotContains(t, got, "stale-model", "passthrough mapping must never reach the public list")
 		})
 	}
 }

backend/internal/service/gateway_service.go

@@ -1433,15 +1433,13 @@ func (s *GatewayService) GetAvailableModels(ctx context.Context, groupID *int64,
 	hasAnyMapping := false
 
 	for _, acc := range accounts {
-		// Passthrough routing accepts models independently of model_mapping. A stale
-		// mapping on any eligible passthrough account therefore cannot define the
-		// public whitelist; return nil so the handler uses its default model set.
+		// Passthrough routing accepts models independently of model_mapping, so a
+		// stale mapping on a passthrough account must not narrow the public list.
+		// Treat it like an unmapped account: skip its mapping here and let
+		// supplementUnmappedOpenAIModels contribute the default set. Mappings on
+		// the ordinary accounts in the same group still count.
 		if platform == PlatformOpenAI && acc.IsOpenAIPassthroughEnabled() {
-			if s.modelsListCache != nil {
-				s.modelsListCache.Set(cacheKey, []string(nil), s.modelsListCacheTTL)
-				modelsListCacheStoreTotal.Add(1)
-			}
-			return nil
+			continue
 		}
 
 		mapping := acc.GetModelMapping()

backend/internal/service/group_model_allowlist.go

@@ -29,15 +29,17 @@ func GroupModelAllowlistFromDomain(cfg domain.GroupModelAllowlist) GroupModelAll
 }
 
 // supplementUnmappedOpenAIModels ensures a partial mapping catalog does not
-// hide models from unmapped OpenAI accounts. An empty catalog is left unchanged
-// so callers retain their existing discovery fallback.
+// hide models from unmapped or passthrough OpenAI accounts (passthrough routing
+// ignores model_mapping, so it serves the same default set as an unmapped
+// account). An empty catalog is left unchanged so callers retain their existing
+// discovery fallback.
 func supplementUnmappedOpenAIModels(accounts []Account, models []string) []string {
 	if len(models) == 0 {
 		return models
 	}
 	for i := range accounts {
 		account := &accounts[i]
-		if account.Platform == PlatformOpenAI && len(account.GetModelMapping()) == 0 {
+		if account.Platform == PlatformOpenAI && (account.IsOpenAIPassthroughEnabled() || len(account.GetModelMapping()) == 0) {
 			return dedupeAndSortModelIDs(slices.Concat(models, openai.DefaultModelIDs()))
 		}
 	}