feat: first party Anthropic (api.anthropic.com) support (#1369)

**Description**

This commit adds support for the first party Anthropic API
api.anthropic.com in the project. Notably, this adds the passthrough
"translator" that captures the token usage as well as the API for the
Anthropic API key configuration which is slightly different from both
the existing APIKey security policy (authorization header) as well as
Azure API key (api-key header) in the sense that it requires the key
passed as "x-api-key" header.

**Related Issues/PRs (if applicable)**

#847

---------

Signed-off-by: Takeshi Yoneda <[email protected]>

Author: mathetake

.github/workflows/build_and_test.yaml

@@ -227,6 +227,7 @@ jobs:
           TEST_AWS_ACCESS_KEY_ID: ${{ secrets.AWS_BEDROCK_USER_AWS_ACCESS_KEY_ID }}
           TEST_AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_BEDROCK_USER_AWS_SECRET_ACCESS_KEY }}
           TEST_OPENAI_API_KEY: ${{ secrets.ENVOY_AI_GATEWAY_OPENAI_API_KEY }}
+          TEST_ANTHROPIC_API_KEY: ${{ secrets.ENVOY_AI_GATEWAY_ANTHROPIC_API_KEY }}
           TEST_GEMINI_API_KEY: ${{ secrets.ENVOY_AI_GATEWAY_GEMINI_API_KEY }}
         run: make test-e2e
 

api/v1alpha1/backendsecurity_policy.go

@@ -19,6 +19,7 @@ const (
 	BackendSecurityPolicyTypeAPIKey           BackendSecurityPolicyType = "APIKey"
 	BackendSecurityPolicyTypeAWSCredentials   BackendSecurityPolicyType = "AWSCredentials"
 	BackendSecurityPolicyTypeAzureAPIKey      BackendSecurityPolicyType = "AzureAPIKey"
+	BackendSecurityPolicyTypeAnthropicAPIKey  BackendSecurityPolicyType = "AnthropicAPIKey" // #nosec G101
 	BackendSecurityPolicyTypeAzureCredentials BackendSecurityPolicyType = "AzureCredentials"
 	BackendSecurityPolicyTypeGCPCredentials   BackendSecurityPolicyType = "GCPCredentials"
 )
@@ -43,11 +44,12 @@ type BackendSecurityPolicy struct {
 //
 // Only one type of BackendSecurityPolicy can be defined.
 // +kubebuilder:validation:MaxProperties=3
-// +kubebuilder:validation:XValidation:rule="self.type == 'APIKey' ? (has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureAPIKey) && !has(self.azureCredentials) && !has(self.gcpCredentials)) : true",message="When type is APIKey, only apiKey field should be set"
-// +kubebuilder:validation:XValidation:rule="self.type == 'AWSCredentials' ? (has(self.awsCredentials) && !has(self.apiKey) && !has(self.azureAPIKey) && !has(self.azureCredentials) && !has(self.gcpCredentials)) : true",message="When type is AWSCredentials, only awsCredentials field should be set"
-// +kubebuilder:validation:XValidation:rule="self.type == 'AzureAPIKey' ? (has(self.azureAPIKey) && !has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureCredentials) && !has(self.gcpCredentials)) : true",message="When type is AzureAPIKey, only azureAPIKey field should be set"
-// +kubebuilder:validation:XValidation:rule="self.type == 'AzureCredentials' ? (has(self.azureCredentials) && !has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureAPIKey) && !has(self.gcpCredentials)) : true",message="When type is AzureCredentials, only azureCredentials field should be set"
-// +kubebuilder:validation:XValidation:rule="self.type == 'GCPCredentials' ? (has(self.gcpCredentials) && !has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureAPIKey) && !has(self.azureCredentials)) : true",message="When type is GCPCredentials, only gcpCredentials field should be set"
+// +kubebuilder:validation:XValidation:rule="self.type == 'APIKey' ? (has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureAPIKey) && !has(self.azureCredentials) && !has(self.gcpCredentials) && !has(self.anthropicAPIKey)) : true",message="When type is APIKey, only apiKey field should be set"
+// +kubebuilder:validation:XValidation:rule="self.type == 'AWSCredentials' ? (has(self.awsCredentials) && !has(self.apiKey) && !has(self.azureAPIKey) && !has(self.azureCredentials) && !has(self.gcpCredentials) && !has(self.anthropicAPIKey)) : true",message="When type is AWSCredentials, only awsCredentials field should be set"
+// +kubebuilder:validation:XValidation:rule="self.type == 'AzureAPIKey' ? (has(self.azureAPIKey) && !has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureCredentials) && !has(self.gcpCredentials) && !has(self.anthropicAPIKey)) : true",message="When type is AzureAPIKey, only azureAPIKey field should be set"
+// +kubebuilder:validation:XValidation:rule="self.type == 'AzureCredentials' ? (has(self.azureCredentials) && !has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureAPIKey) && !has(self.gcpCredentials) && !has(self.anthropicAPIKey)) : true",message="When type is AzureCredentials, only azureCredentials field should be set"
+// +kubebuilder:validation:XValidation:rule="self.type == 'GCPCredentials' ? (has(self.gcpCredentials) && !has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureAPIKey) && !has(self.azureCredentials) && !has(self.anthropicAPIKey)) : true",message="When type is GCPCredentials, only gcpCredentials field should be set"
+// +kubebuilder:validation:XValidation:rule="self.type == 'AnthropicAPIKey' ? (has(self.anthropicAPIKey) && !has(self.apiKey) && !has(self.awsCredentials) && !has(self.azureAPIKey) && !has(self.azureCredentials) && !has(self.gcpCredentials)) : true",message="When type is AnthropicAPIKey, only anthropicAPIKey field should be set"
 type BackendSecurityPolicySpec struct {
 	// TargetRefs are the names of the AIServiceBackend resources this BackendSecurityPolicy is being attached to.
 	// Attaching multiple BackendSecurityPolicies to the same AIServiceBackend is invalid and will result in an error
@@ -60,7 +62,7 @@ type BackendSecurityPolicySpec struct {
 
 	// Type specifies the type of the backend security policy.
 	//
-	// +kubebuilder:validation:Enum=APIKey;AWSCredentials;AzureAPIKey;AzureCredentials;GCPCredentials
+	// +kubebuilder:validation:Enum=APIKey;AWSCredentials;AzureAPIKey;AzureCredentials;GCPCredentials;AnthropicAPIKey
 	Type BackendSecurityPolicyType `json:"type"`
 
 	// APIKey is a mechanism to access a backend(s). The API key will be injected into the Authorization header.
@@ -82,10 +84,17 @@ type BackendSecurityPolicySpec struct {
 	//
 	// +optional
 	AzureCredentials *BackendSecurityPolicyAzureCredentials `json:"azureCredentials,omitempty"`
+
 	// GCPCredentials is a mechanism to access a backend(s). GCP specific logic will be applied.
 	//
 	// +optional
 	GCPCredentials *BackendSecurityPolicyGCPCredentials `json:"gcpCredentials,omitempty"`
+
+	// AnthropicAPIKey is a mechanism to access Anthropic backend(s). The API key will be injected into the "x-api-key" header.
+	// https://docs.claude.com/en/api/overview#authentication
+	//
+	// +optional
+	AnthropicAPIKey *BackendSecurityPolicyAnthropicAPIKey `json:"anthropicAPIKey,omitempty"`
 }
 
 // BackendSecurityPolicyList contains a list of BackendSecurityPolicy
@@ -314,3 +323,11 @@ type GCPCredentialsFile struct {
 	// The secret should contain the GCP service account credentials file keyed on "service_account.json".
 	SecretRef *gwapiv1.SecretObjectReference `json:"secretRef"`
 }
+
+// BackendSecurityPolicyAnthropicAPIKey specifies the Anthropic API key.
+type BackendSecurityPolicyAnthropicAPIKey struct {
+	// SecretRef is the reference to the secret containing the Anthropic API key.
+	// ai-gateway must be given the permission to read this secret.
+	// The key of the secret should be "apiKey".
+	SecretRef *gwapiv1.SecretObjectReference `json:"secretRef"`
+}

api/v1alpha1/shared_types.go

@@ -15,7 +15,7 @@ package v1alpha1
 type VersionedAPISchema struct {
 	// Name is the name of the API schema of the AIGatewayRoute or AIServiceBackend.
 	//
-	// +kubebuilder:validation:Enum=OpenAI;AWSBedrock;AzureOpenAI;GCPVertexAI;GCPAnthropic
+	// +kubebuilder:validation:Enum=OpenAI;AWSBedrock;AzureOpenAI;GCPVertexAI;GCPAnthropic;Anthropic
 	Name APISchema `json:"name"`
 
 	// Version is the version of the API schema.
@@ -62,6 +62,9 @@ const (
 	//
 	// https://docs.anthropic.com/en/api/claude-on-vertex-ai
 	APISchemaGCPAnthropic APISchema = "GCPAnthropic"
+	// APISchemaAnthropic is the native Anthropic API schema.
+	// https://docs.claude.com/en/home
+	APISchemaAnthropic APISchema = "Anthropic"
 )
 
 const (

api/v1alpha1/zz_generated.deepcopy.go

@@ -0,0 +1,86 @@
+# Copyright Envoy AI Gateway Authors
+# SPDX-License-Identifier: Apache-2.0
+# The full text of the Apache license is available in the LICENSE file at
+# the root of the repo.
+
+apiVersion: aigateway.envoyproxy.io/v1alpha1
+kind: AIGatewayRoute
+metadata:
+  name: envoy-ai-gateway-basic-anthropic
+  namespace: default
+spec:
+  parentRefs:
+    - name: envoy-ai-gateway-basic
+      kind: Gateway
+      group: gateway.networking.k8s.io
+  rules:
+    - matches:
+        - headers:
+            - type: Exact
+              name: x-ai-eg-model
+              value: claude-sonnet-4-5
+      backendRefs:
+        - name: envoy-ai-gateway-basic-anthropic
+---
+apiVersion: aigateway.envoyproxy.io/v1alpha1
+kind: AIServiceBackend
+metadata:
+  name: envoy-ai-gateway-basic-anthropic
+  namespace: default
+spec:
+  schema:
+    name: Anthropic
+  backendRef:
+    name: envoy-ai-gateway-basic-anthropic
+    kind: Backend
+    group: gateway.envoyproxy.io
+---
+apiVersion: aigateway.envoyproxy.io/v1alpha1
+kind: BackendSecurityPolicy
+metadata:
+  name: envoy-ai-gateway-basic-anthropic-apikey
+  namespace: default
+spec:
+  targetRefs:
+    - group: aigateway.envoyproxy.io
+      kind: AIServiceBackend
+      name: envoy-ai-gateway-basic-anthropic
+  type: AnthropicAPIKey
+  anthropicAPIKey:
+    secretRef:
+      name: envoy-ai-gateway-basic-anthropic-apikey
+      namespace: default
+---
+apiVersion: gateway.envoyproxy.io/v1alpha1
+kind: Backend
+metadata:
+  name: envoy-ai-gateway-basic-anthropic
+  namespace: default
+spec:
+  endpoints:
+    - fqdn:
+        hostname: api.anthropic.com
+        port: 443
+---
+apiVersion: gateway.networking.k8s.io/v1alpha3
+kind: BackendTLSPolicy
+metadata:
+  name: envoy-ai-gateway-basic-anthropic-tls
+  namespace: default
+spec:
+  targetRefs:
+    - group: "gateway.envoyproxy.io"
+      kind: Backend
+      name: envoy-ai-gateway-basic-anthropic
+  validation:
+    wellKnownCACertificates: "System"
+    hostname: api.anthropic.com
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: envoy-ai-gateway-basic-anthropic-apikey
+  namespace: default
+type: Opaque
+stringData:
+  apiKey: ANTHROPIC_API_KEY # Replace with your Anthropic API key.

examples/basic/anthropic.yaml

@@ -86,7 +86,9 @@ func (c *BackendSecurityPolicyController) reconcile(ctx context.Context, bsp *ai
 	if handleFinalizer(ctx, c.client, c.logger, bsp, c.syncBackendSecurityPolicy) { // Propagate the bsp deletion all the way to relevant Gateways.
 		return res, nil
 	}
-	if bsp.Spec.Type != aigv1a1.BackendSecurityPolicyTypeAPIKey && bsp.Spec.Type != aigv1a1.BackendSecurityPolicyTypeAzureAPIKey {
+	if bsp.Spec.Type != aigv1a1.BackendSecurityPolicyTypeAPIKey &&
+		bsp.Spec.Type != aigv1a1.BackendSecurityPolicyTypeAzureAPIKey &&
+		bsp.Spec.Type != aigv1a1.BackendSecurityPolicyTypeAnthropicAPIKey {
 		res, err = c.rotateCredential(ctx, bsp)
 		if err != nil {
 			return res, err
@@ -385,10 +387,10 @@ func getBSPGeneratedSecretName(bsp *aigv1a1.BackendSecurityPolicy) string {
 		if bsp.Spec.GCPCredentials.WorkloadIdentityFederationConfig == nil {
 			return ""
 		}
-	case aigv1a1.BackendSecurityPolicyTypeAPIKey:
+	case aigv1a1.BackendSecurityPolicyTypeAPIKey,
+		aigv1a1.BackendSecurityPolicyTypeAzureAPIKey,
+		aigv1a1.BackendSecurityPolicyTypeAnthropicAPIKey:
 		return "" // APIKey does not require rotation.
-	case aigv1a1.BackendSecurityPolicyTypeAzureAPIKey:
-		return "" // AzureAPIKey does not require rotation.
 	default:
 		panic("BUG: unsupported backend security policy type: " + string(bsp.Spec.Type))
 	}

internal/controller/backend_security_policy.go

@@ -357,6 +357,9 @@ func backendSecurityPolicyIndexFunc(o client.Object) []string {
 	case aigv1a1.BackendSecurityPolicyTypeAzureAPIKey:
 		apiKey := backendSecurityPolicy.Spec.AzureAPIKey
 		key = getSecretNameAndNamespace(apiKey.SecretRef, backendSecurityPolicy.Namespace)
+	case aigv1a1.BackendSecurityPolicyTypeAnthropicAPIKey:
+		apiKey := backendSecurityPolicy.Spec.AnthropicAPIKey
+		key = getSecretNameAndNamespace(apiKey.SecretRef, backendSecurityPolicy.Namespace)
 	case aigv1a1.BackendSecurityPolicyTypeAzureCredentials:
 		azureCreds := backendSecurityPolicy.Spec.AzureCredentials
 		if azureCreds.ClientSecretRef != nil {

internal/controller/controller.go

@@ -222,6 +222,19 @@ func Test_backendSecurityPolicyIndexFunc(t *testing.T) {
 			},
 			expKey: "some-backend-security-policy-10.foo",
 		},
+		{
+			name: "anthropic api key",
+			backendSecurityPolicy: &aigv1a1.BackendSecurityPolicy{
+				ObjectMeta: metav1.ObjectMeta{Name: "some-backend-security-policy-2", Namespace: "ns"},
+				Spec: aigv1a1.BackendSecurityPolicySpec{
+					Type: aigv1a1.BackendSecurityPolicyTypeAnthropicAPIKey,
+					AnthropicAPIKey: &aigv1a1.BackendSecurityPolicyAnthropicAPIKey{
+						SecretRef: &gwapiv1.SecretObjectReference{Name: "some-aaaa"},
+					},
+				},
+			},
+			expKey: "some-aaaa.ns",
+		},
 	} {
 		t.Run(bsp.name, func(t *testing.T) {
 			c := fake.NewClientBuilder().

internal/controller/controller_test.go

@@ -367,6 +367,13 @@ func (c *GatewayController) bspToFilterAPIBackendAuth(ctx context.Context, backe
 			return nil, fmt.Errorf("failed to get secret %s: %w", secretName, err)
 		}
 		return &filterapi.BackendAuth{AzureAPIKey: &filterapi.AzureAPIKeyAuth{Key: apiKey}}, nil
+	case aigv1a1.BackendSecurityPolicyTypeAnthropicAPIKey:
+		secretName := string(backendSecurityPolicy.Spec.AnthropicAPIKey.SecretRef.Name)
+		apiKey, err := c.getSecretData(ctx, namespace, secretName, apiKeyInSecret)
+		if err != nil {
+			return nil, fmt.Errorf("failed to get secret %s: %w", secretName, err)
+		}
+		return &filterapi.BackendAuth{AnthropicAPIKey: &filterapi.AnthropicAPIKeyAuth{Key: apiKey}}, nil
 	case aigv1a1.BackendSecurityPolicyTypeAWSCredentials:
 		var secretName string
 		if awsCred := backendSecurityPolicy.Spec.AWSCredentials; awsCred.CredentialsFile != nil {

internal/controller/gateway.go

@@ -464,6 +464,15 @@ func TestGatewayController_bspToFilterAPIBackendAuth(t *testing.T) {
 				},
 			},
 		},
+		{
+			ObjectMeta: metav1.ObjectMeta{Name: "bsp-anthropic-apikey", Namespace: namespace},
+			Spec: aigv1a1.BackendSecurityPolicySpec{
+				Type: aigv1a1.BackendSecurityPolicyTypeAnthropicAPIKey,
+				AnthropicAPIKey: &aigv1a1.BackendSecurityPolicyAnthropicAPIKey{
+					SecretRef: &gwapiv1.SecretObjectReference{Name: "api-key-secret"},
+				},
+			},
+		},
 	} {
 		require.NoError(t, fakeClient.Create(t.Context(), bsp))
 	}
@@ -531,6 +540,12 @@ func TestGatewayController_bspToFilterAPIBackendAuth(t *testing.T) {
 				GCPAuth: &filterapi.GCPAuth{AccessToken: "thisisgcpcredentials"},
 			},
 		},
+		{
+			bspName: "bsp-anthropic-apikey",
+			exp: &filterapi.BackendAuth{
+				AnthropicAPIKey: &filterapi.AnthropicAPIKeyAuth{Key: "thisisapikey"},
+			},
+		},
 	} {
 		t.Run(tc.bspName, func(t *testing.T) {
 			bsp := &aigv1a1.BackendSecurityPolicy{}