feat(js/plugins/vertexai): add support to anthropic prompt caching

Author: amondnet

js/plugins/vertexai/src/modelgarden/anthropic.ts

@@ -309,6 +309,15 @@ export function fromAnthropicResponse(
     role: 'model',
     content: parts.map(fromAnthropicPart),
   };
+  let usageCustom: Record<string, number> | undefined = undefined;
+  if ( response.usage.cache_creation_input_tokens) {
+    usageCustom = {};
+    usageCustom['cacheCreationInputTokens']=  response.usage.cache_creation_input_tokens;
+  }
+  if ( response.usage.cache_read_input_tokens) {
+    usageCustom = usageCustom || {};
+    usageCustom['cacheReadInputTokens']=  response.usage.cache_read_input_tokens;
+  }
   return {
     message,
     finishReason: toGenkitFinishReason(
@@ -328,6 +337,7 @@ export function fromAnthropicResponse(
       ...getBasicUsageStats(input.messages, message),
       inputTokens: response.usage.input_tokens,
       outputTokens: response.usage.output_tokens,
+      custom: usageCustom
     },
   };
 }

js/plugins/vertexai/tests/modelgarden/anthropic_test.ts

@@ -134,10 +134,12 @@ describe('toAnthropicRequest', () => {
         messages: [
           {
             role: 'user',
-            content: {
-              type: 'text',
-              text: 'What are the key terms and conditions in this agreement?',
-            },
+            content: [
+              {
+                type: 'text',
+                text: 'What are the key terms and conditions in this agreement?',
+              },
+            ],
           },
         ],
       },
@@ -218,6 +220,8 @@ describe('fromAnthropicResponse', () => {
         usage: {
           input_tokens: 123,
           output_tokens: 234,
+          cache_creation_input_tokens: 0,
+          cache_read_input_tokens: 0,
         },
         stop_sequence: null,
         type: 'message',
@@ -300,6 +304,8 @@ describe('fromAnthropicResponse', () => {
         usage: {
           input_tokens: 123,
           output_tokens: 234,
+          cache_creation_input_tokens: 0,
+          cache_read_input_tokens: 0,
         },
         content: [
           {