Add a responseMimeType to generationConfig (#133)

Provide Apps with an ability to configure the responseMimeType. This enables applications to request that VertexAI returns the response in a JSON format instead of a normal textual format.

.changeset/dirty-snails-unite.md

@@ -0,0 +1,5 @@
+---
+"@google/generative-ai": minor
+---
+
+Added responseMimeType to GenerationConfig to allow for JSON formatted responses.

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

@@ -18,6 +18,7 @@ export interface GenerationConfig
 |  --- | --- | --- | --- |
 |  [candidateCount?](./generative-ai.generationconfig.candidatecount.md) |  | number | _(Optional)_ |
 |  [maxOutputTokens?](./generative-ai.generationconfig.maxoutputtokens.md) |  | number | _(Optional)_ |
+|  [responseMimeType?](./generative-ai.generationconfig.responsemimetype.md) |  | string | _(Optional)_ Output response mimetype of the generated candidate text. Supported mimetype: <code>text/plain</code>: (default) Text output. <code>application/json</code>: JSON response in the candidates. |
 |  [stopSequences?](./generative-ai.generationconfig.stopsequences.md) |  | string\[\] | _(Optional)_ |
 |  [temperature?](./generative-ai.generationconfig.temperature.md) |  | number | _(Optional)_ |
 |  [topK?](./generative-ai.generationconfig.topk.md) |  | number | _(Optional)_ |

docs/reference/main/generative-ai.generationconfig.responsemimetype.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; [GenerationConfig](./generative-ai.generationconfig.md) &gt; [responseMimeType](./generative-ai.generationconfig.responsemimetype.md)
+
+## GenerationConfig.responseMimeType property
+
+Output response mimetype of the generated candidate text. Supported mimetype: `text/plain`<!-- -->: (default) Text output. `application/json`<!-- -->: JSON response in the candidates.
+
+**Signature:**
+
+```typescript
+responseMimeType?: string;
+```

packages/main/types/requests.ts

@@ -74,6 +74,13 @@ export interface GenerationConfig {
   temperature?: number;
   topP?: number;
   topK?: number;
+  /**
+   * Output response mimetype of the generated candidate text.
+   * Supported mimetype:
+   *   `text/plain`: (default) Text output.
+   *   `application/json`: JSON response in the candidates.
+   */
+  responseMimeType?: string;
 }
 
 /**