feat(ai): add Anthropic provider option

internal/ai/ai.go

@@ -10,6 +10,8 @@ const (
 	ProviderOpenAICompatible ProviderType = "OPENAI_COMPATIBLE"
 	// ProviderGemini is Google's Gemini API.
 	ProviderGemini ProviderType = "GEMINI"
+	// ProviderAnthropic is Anthropic's API.
+	ProviderAnthropic ProviderType = "ANTHROPIC"
 )
 
 // ProviderConfig configures a callable AI provider connection.

proto/api/v1/instance_service.proto

@@ -233,6 +233,7 @@ message InstanceSetting {
     OPENAI = 1;
     OPENAI_COMPATIBLE = 2;
     GEMINI = 3;
+    ANTHROPIC = 4;
   }
 }
 

proto/gen/api/v1/instance_service.pb.go

@@ -100,6 +100,7 @@ const (
 	InstanceSetting_OPENAI                       InstanceSetting_AIProviderType = 1
 	InstanceSetting_OPENAI_COMPATIBLE            InstanceSetting_AIProviderType = 2
 	InstanceSetting_GEMINI                       InstanceSetting_AIProviderType = 3
+	InstanceSetting_ANTHROPIC                    InstanceSetting_AIProviderType = 4
 )
 
 // Enum value maps for InstanceSetting_AIProviderType.
@@ -109,12 +110,14 @@ var (
 		1: "OPENAI",
 		2: "OPENAI_COMPATIBLE",
 		3: "GEMINI",
+		4: "ANTHROPIC",
 	}
 	InstanceSetting_AIProviderType_value = map[string]int32{
 		"AI_PROVIDER_TYPE_UNSPECIFIED": 0,
 		"OPENAI":                       1,
 		"OPENAI_COMPATIBLE":            2,
 		"GEMINI":                       3,
+		"ANTHROPIC":                    4,
 	}
 )
 
@@ -1411,7 +1414,7 @@ const file_api_v1_instance_service_proto_rawDesc = "" +
 	"\x04demo\x18\x03 \x01(\bR\x04demo\x12!\n" +
 	"\finstance_url\x18\x06 \x01(\tR\vinstanceUrl\x12(\n" +
 	"\x05admin\x18\a \x01(\v2\x12.memos.api.v1.UserR\x05admin\"\x1b\n" +
-	"\x19GetInstanceProfileRequest\"\xd3\x1a\n" +
+	"\x19GetInstanceProfileRequest\"\xe2\x1a\n" +
 	"\x0fInstanceSetting\x12\x17\n" +
 	"\x04name\x18\x01 \x01(\tB\x03\xe0A\bR\x04name\x12W\n" +
 	"\x0fgeneral_setting\x18\x02 \x01(\v2,.memos.api.v1.InstanceSetting.GeneralSettingH\x00R\x0egeneralSetting\x12W\n" +
@@ -1499,14 +1502,15 @@ const file_api_v1_instance_service_proto_rawDesc = "" +
 	"\fMEMO_RELATED\x10\x03\x12\b\n" +
 	"\x04TAGS\x10\x04\x12\x10\n" +
 	"\fNOTIFICATION\x10\x05\x12\x06\n" +
-	"\x02AI\x10\x06\"a\n" +
+	"\x02AI\x10\x06\"p\n" +
 	"\x0eAIProviderType\x12 \n" +
 	"\x1cAI_PROVIDER_TYPE_UNSPECIFIED\x10\x00\x12\n" +
 	"\n" +
 	"\x06OPENAI\x10\x01\x12\x15\n" +
 	"\x11OPENAI_COMPATIBLE\x10\x02\x12\n" +
 	"\n" +
-	"\x06GEMINI\x10\x03:a\xeaA^\n" +
+	"\x06GEMINI\x10\x03\x12\r\n" +
+	"\tANTHROPIC\x10\x04:a\xeaA^\n" +
 	"\x1cmemos.api.v1/InstanceSetting\x12\x1binstance/settings/{setting}*\x10instanceSettings2\x0finstanceSettingB\a\n" +
 	"\x05value\"U\n" +
 	"\x19GetInstanceSettingRequest\x128\n" +

proto/gen/openapi.yaml

@@ -2421,6 +2421,7 @@ components:
                         - OPENAI
                         - OPENAI_COMPATIBLE
                         - GEMINI
+                        - ANTHROPIC
                     type: string
                     format: enum
                 endpoint:

proto/gen/store/instance_setting.pb.go

@@ -100,6 +100,7 @@ const (
 	AIProviderType_OPENAI                       AIProviderType = 1
 	AIProviderType_OPENAI_COMPATIBLE            AIProviderType = 2
 	AIProviderType_GEMINI                       AIProviderType = 3
+	AIProviderType_ANTHROPIC                    AIProviderType = 4
 )
 
 // Enum value maps for AIProviderType.
@@ -109,12 +110,14 @@ var (
 		1: "OPENAI",
 		2: "OPENAI_COMPATIBLE",
 		3: "GEMINI",
+		4: "ANTHROPIC",
 	}
 	AIProviderType_value = map[string]int32{
 		"AI_PROVIDER_TYPE_UNSPECIFIED": 0,
 		"OPENAI":                       1,
 		"OPENAI_COMPATIBLE":            2,
 		"GEMINI":                       3,
+		"ANTHROPIC":                    4,
 	}
 )
 
@@ -1321,14 +1324,15 @@ const file_store_instance_setting_proto_rawDesc = "" +
 	"\fMEMO_RELATED\x10\x04\x12\b\n" +
 	"\x04TAGS\x10\x05\x12\x10\n" +
 	"\fNOTIFICATION\x10\x06\x12\x06\n" +
-	"\x02AI\x10\a*a\n" +
+	"\x02AI\x10\a*p\n" +
 	"\x0eAIProviderType\x12 \n" +
 	"\x1cAI_PROVIDER_TYPE_UNSPECIFIED\x10\x00\x12\n" +
 	"\n" +
 	"\x06OPENAI\x10\x01\x12\x15\n" +
 	"\x11OPENAI_COMPATIBLE\x10\x02\x12\n" +
 	"\n" +
-	"\x06GEMINI\x10\x03B\x9f\x01\n" +
+	"\x06GEMINI\x10\x03\x12\r\n" +
+	"\tANTHROPIC\x10\x04B\x9f\x01\n" +
 	"\x0fcom.memos.storeB\x14InstanceSettingProtoP\x01Z)github.com/usememos/memos/proto/gen/store\xa2\x02\x03MSX\xaa\x02\vMemos.Store\xca\x02\vMemos\\Store\xe2\x02\x17Memos\\Store\\GPBMetadata\xea\x02\fMemos::Storeb\x06proto3"
 
 var (

proto/store/instance_setting.proto

@@ -167,4 +167,5 @@ enum AIProviderType {
   OPENAI = 1;
   OPENAI_COMPATIBLE = 2;
   GEMINI = 3;
+  ANTHROPIC = 4;
 }

server/router/api/v1/ai_service.go

@@ -170,6 +170,8 @@ func convertAIProviderTypeFromStore(providerType storepb.AIProviderType) ai.Prov
 		return ai.ProviderOpenAICompatible
 	case storepb.AIProviderType_GEMINI:
 		return ai.ProviderGemini
+	case storepb.AIProviderType_ANTHROPIC:
+		return ai.ProviderAnthropic
 	default:
 		return ""
 	}

server/router/api/v1/instance_service.go

@@ -523,6 +523,9 @@ func (s *APIV1Service) prepareInstanceAISettingForUpdate(ctx context.Context, se
 		if provider.Type == storepb.AIProviderType_OPENAI && provider.Endpoint == "" {
 			provider.Endpoint = "https://api.openai.com/v1"
 		}
+		if provider.Type == storepb.AIProviderType_ANTHROPIC && provider.Endpoint == "" {
+			provider.Endpoint = "https://api.anthropic.com/v1"
+		}
 		if provider.Type == storepb.AIProviderType_OPENAI_COMPATIBLE && provider.Endpoint == "" {
 			return errors.Errorf("provider %q endpoint is required", provider.Id)
 		}

server/router/api/v1/test/ai_service_test.go

@@ -154,6 +154,47 @@ func TestTranscribe(t *testing.T) {
 		require.Equal(t, "gemini transcript", resp.Text)
 	})
 
+	t.Run("rejects Anthropic transcription as unsupported", func(t *testing.T) {
+		ts := NewTestService(t)
+		defer ts.Cleanup()
+
+		user, err := ts.CreateRegularUser(ctx, "anthropic-user")
+		require.NoError(t, err)
+		userCtx := ts.CreateUserContext(ctx, user.ID)
+
+		_, err = ts.Store.UpsertInstanceSetting(ctx, &storepb.InstanceSetting{
+			Key: storepb.InstanceSettingKey_AI,
+			Value: &storepb.InstanceSetting_AiSetting{
+				AiSetting: &storepb.InstanceAISetting{
+					Providers: []*storepb.AIProviderConfig{
+						{
+							Id:           "anthropic-main",
+							Title:        "Anthropic",
+							Type:         storepb.AIProviderType_ANTHROPIC,
+							Endpoint:     "https://api.anthropic.com/v1",
+							ApiKey:       "sk-ant-test",
+							Models:       []string{"claude-sonnet-4-5"},
+							DefaultModel: "claude-sonnet-4-5",
+						},
+					},
+				},
+			},
+		})
+		require.NoError(t, err)
+
+		_, err = ts.Service.Transcribe(userCtx, &v1pb.TranscribeRequest{
+			ProviderId: "anthropic-main",
+			Config:     &v1pb.TranscriptionConfig{},
+			Audio: &v1pb.TranscriptionAudio{
+				Source:      &v1pb.TranscriptionAudio_Content{Content: []byte("RIFF")},
+				Filename:    "voice.wav",
+				ContentType: "audio/wav",
+			},
+		})
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "capability unsupported")
+	})
+
 	t.Run("rejects unconfigured model", func(t *testing.T) {
 		ts := NewTestService(t)
 		defer ts.Cleanup()

server/router/api/v1/test/instance_service_test.go

@@ -624,4 +624,39 @@ func TestUpdateInstanceSetting(t *testing.T) {
 		require.Equal(t, []string{"gpt-5.4-mini", "gpt-5.4"}, stored.GetProviders()[0].GetModels())
 		require.Equal(t, "gpt-5.4-mini", stored.GetProviders()[0].GetDefaultModel())
 	})
+
+	t.Run("UpdateInstanceSetting - Anthropic provider gets default endpoint", func(t *testing.T) {
+		ts := NewTestService(t)
+		defer ts.Cleanup()
+
+		hostUser, err := ts.CreateHostUser(ctx, "admin")
+		require.NoError(t, err)
+		adminCtx := ts.CreateUserContext(ctx, hostUser.ID)
+
+		_, err = ts.Service.UpdateInstanceSetting(adminCtx, &v1pb.UpdateInstanceSettingRequest{
+			Setting: &v1pb.InstanceSetting{
+				Name: "instance/settings/AI",
+				Value: &v1pb.InstanceSetting_AiSetting{
+					AiSetting: &v1pb.InstanceSetting_AISetting{
+						Providers: []*v1pb.InstanceSetting_AIProviderConfig{
+							{
+								Id:           "anthropic-main",
+								Title:        "Anthropic",
+								Type:         v1pb.InstanceSetting_ANTHROPIC,
+								ApiKey:       "sk-ant-test",
+								Models:       []string{"claude-sonnet-4-5"},
+								DefaultModel: "claude-sonnet-4-5",
+							},
+						},
+					},
+				},
+			},
+		})
+		require.NoError(t, err)
+
+		stored, err := ts.Store.GetInstanceAISetting(ctx)
+		require.NoError(t, err)
+		require.Len(t, stored.GetProviders(), 1)
+		require.Equal(t, "https://api.anthropic.com/v1", stored.GetProviders()[0].GetEndpoint())
+	})
 }

web/src/components/Settings/AISection.tsx

@@ -42,6 +42,7 @@ const providerTypeOptions = [
   InstanceSetting_AIProviderType.OPENAI,
   InstanceSetting_AIProviderType.OPENAI_COMPATIBLE,
   InstanceSetting_AIProviderType.GEMINI,
+  InstanceSetting_AIProviderType.ANTHROPIC,
 ];
 
 const createProviderID = () => {