Add UsageMetadata to GenerateContentResponse (#127)

Added the UsageMetadata payload to GenerateContentResponse, and updated docs accordingly.

Author: DellaBitta

.changeset/beige-lamps-sip.md

@@ -0,0 +1,5 @@
+---
+"@google/generative-ai": minor
+---
+
+Added UsageMetadata to GenerateContentResponses.

docs/reference/main/generative-ai.generatecontentresponse.candidates.md

@@ -4,6 +4,8 @@
 
 ## GenerateContentResponse.candidates property
 
+Candidate responses from the model.
+
 **Signature:**
 
 ```typescript

docs/reference/main/generative-ai.generatecontentresponse.md

@@ -16,6 +16,7 @@ export interface GenerateContentResponse
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [candidates?](./generative-ai.generatecontentresponse.candidates.md) |  | [GenerateContentCandidate](./generative-ai.generatecontentcandidate.md)<!-- -->\[\] | _(Optional)_ |
-|  [promptFeedback?](./generative-ai.generatecontentresponse.promptfeedback.md) |  | [PromptFeedback](./generative-ai.promptfeedback.md) | _(Optional)_ |
+|  [candidates?](./generative-ai.generatecontentresponse.candidates.md) |  | [GenerateContentCandidate](./generative-ai.generatecontentcandidate.md)<!-- -->\[\] | _(Optional)_ Candidate responses from the model. |
+|  [promptFeedback?](./generative-ai.generatecontentresponse.promptfeedback.md) |  | [PromptFeedback](./generative-ai.promptfeedback.md) | _(Optional)_ The prompt's feedback related to the content filters. |
+|  [usageMetadata?](./generative-ai.generatecontentresponse.usagemetadata.md) |  | [UsageMetadata](./generative-ai.usagemetadata.md) | _(Optional)_ Metadata on the generation request's token usage. |
 

docs/reference/main/generative-ai.generatecontentresponse.promptfeedback.md

@@ -4,6 +4,8 @@
 
 ## GenerateContentResponse.promptFeedback property
 
+The prompt's feedback related to the content filters.
+
 **Signature:**
 
 ```typescript

docs/reference/main/generative-ai.generatecontentresponse.usagemetadata.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [@google/generative-ai](./generative-ai.md) &gt; [GenerateContentResponse](./generative-ai.generatecontentresponse.md) &gt; [usageMetadata](./generative-ai.generatecontentresponse.usagemetadata.md)
+
+## GenerateContentResponse.usageMetadata property
+
+Metadata on the generation request's token usage.
+
+**Signature:**
+
+```typescript
+usageMetadata?: UsageMetadata;
+```

docs/reference/main/generative-ai.md

@@ -72,6 +72,7 @@
 |  [StartChatParams](./generative-ai.startchatparams.md) | Params for [GenerativeModel.startChat()](./generative-ai.generativemodel.startchat.md)<!-- -->. |
 |  [TextPart](./generative-ai.textpart.md) | Content part interface if the part represents a text string. |
 |  [ToolConfig](./generative-ai.toolconfig.md) | Tool config. This config is shared for all tools provided in the request. |
+|  [UsageMetadata](./generative-ai.usagemetadata.md) | Metadata on the generation request's token usage. |
 
 ## Variables
 

docs/reference/main/generative-ai.usagemetadata.candidatestokencount.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [@google/generative-ai](./generative-ai.md) &gt; [UsageMetadata](./generative-ai.usagemetadata.md) &gt; [candidatesTokenCount](./generative-ai.usagemetadata.candidatestokencount.md)
+
+## UsageMetadata.candidatesTokenCount property
+
+Total number of tokens across the generated candidates.
+
+**Signature:**
+
+```typescript
+candidatesTokenCount: number;
+```

docs/reference/main/generative-ai.usagemetadata.md

@@ -0,0 +1,22 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [@google/generative-ai](./generative-ai.md) &gt; [UsageMetadata](./generative-ai.usagemetadata.md)
+
+## UsageMetadata interface
+
+Metadata on the generation request's token usage.
+
+**Signature:**
+
+```typescript
+export interface UsageMetadata 
+```
+
+## Properties
+
+|  Property | Modifiers | Type | Description |
+|  --- | --- | --- | --- |
+|  [candidatesTokenCount](./generative-ai.usagemetadata.candidatestokencount.md) |  | number | Total number of tokens across the generated candidates. |
+|  [promptTokenCount](./generative-ai.usagemetadata.prompttokencount.md) |  | number | Number of tokens in the prompt. |
+|  [totalTokenCount](./generative-ai.usagemetadata.totaltokencount.md) |  | number | Total token count for the generation request (prompt + candidates). |
+

docs/reference/main/generative-ai.usagemetadata.prompttokencount.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [@google/generative-ai](./generative-ai.md) &gt; [UsageMetadata](./generative-ai.usagemetadata.md) &gt; [promptTokenCount](./generative-ai.usagemetadata.prompttokencount.md)
+
+## UsageMetadata.promptTokenCount property
+
+Number of tokens in the prompt.
+
+**Signature:**
+
+```typescript
+promptTokenCount: number;
+```

docs/reference/main/generative-ai.usagemetadata.totaltokencount.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [@google/generative-ai](./generative-ai.md) &gt; [UsageMetadata](./generative-ai.usagemetadata.md) &gt; [totalTokenCount](./generative-ai.usagemetadata.totaltokencount.md)
+
+## UsageMetadata.totalTokenCount property
+
+Total token count for the generation request (prompt + candidates).
+
+**Signature:**
+
+```typescript
+totalTokenCount: number;
+```

packages/main/types/responses.ts

@@ -79,8 +79,25 @@ export interface EnhancedGenerateContentResponse
  * @public
  */
 export interface GenerateContentResponse {
+  /** Candidate responses from the model. */
   candidates?: GenerateContentCandidate[];
+  /** The prompt's feedback related to the content filters. */
   promptFeedback?: PromptFeedback;
+  /** Metadata on the generation request's token usage. */
+  usageMetadata?: UsageMetadata;
+}
+
+/**
+ * Metadata on the generation request's token usage.
+ * @public
+ */
+export interface UsageMetadata {
+  /** Number of tokens in the prompt. */
+  promptTokenCount: number;
+  /** Total number of tokens across the generated candidates. */
+  candidatesTokenCount: number;
+  /** Total token count for the generation request (prompt + candidates). */
+  totalTokenCount: number;
 }
 
 /**