Backport: Backport: feat(provider/google): add gemini-3.5-flash (#15439)

This is an automated backport of #15436 to the release-v5.0 branch. FYI
@felixarntz
~~This backport has conflicts that need to be resolved manually.~~
Conflicts resolved.

### `git cherry-pick` output

```
Auto-merging content/providers/01-ai-sdk-providers/15-google-generative-ai.mdx
Auto-merging content/providers/01-ai-sdk-providers/16-google-vertex.mdx
CONFLICT (content): Merge conflict in content/providers/01-ai-sdk-providers/16-google-vertex.mdx
CONFLICT (file location): examples/ai-functions/src/generate-text/google/gemini-3-5-flash.ts added in 756fec1 (Backport: feat(provider/google): add `gemini-3.5-flash` (#15436)) inside a directory that was renamed in HEAD, suggesting it should perhaps be moved to examples/ai-core/src/generate-text/gemini-3-5-flash.ts.
Auto-merging examples/ai-core/src/generate-text/google-function-call-id.ts
CONFLICT (file location): examples/ai-functions/src/generate-text/google/interactions-gemini-3-5-flash.ts added in 756fec1 (Backport: feat(provider/google): add `gemini-3.5-flash` (#15436)) inside a directory that was renamed in HEAD, suggesting it should perhaps be moved to examples/ai-core/src/generate-text/interactions-gemini-3-5-flash.ts.
CONFLICT (file location): examples/ai-functions/src/stream-text/google/gemini-3-5-flash.ts added in 756fec1 (Backport: feat(provider/google): add `gemini-3.5-flash` (#15436)) inside a directory that was renamed in HEAD, suggesting it should perhaps be moved to examples/ai-core/src/stream-text/gemini-3-5-flash.ts.
Auto-merging examples/ai-core/src/stream-text/google-function-call-id.ts
CONFLICT (file location): examples/ai-functions/src/stream-text/google/interactions-gemini-3-5-flash.ts added in 756fec1 (Backport: feat(provider/google): add `gemini-3.5-flash` (#15436)) inside a directory that was renamed in HEAD, suggesting it should perhaps be moved to examples/ai-core/src/stream-text/interactions-gemini-3-5-flash.ts.
Auto-merging packages/google-vertex/src/google-vertex-options.ts
Auto-merging packages/google/src/google-generative-ai-options.ts
CONFLICT (modify/delete): packages/google/src/interactions/google-interactions-language-model-options.ts deleted in HEAD and modified in 756fec1 (Backport: feat(provider/google): add `gemini-3.5-flash` (#15436)).  Version 756fec1 (Backport: feat(provider/google): add `gemini-3.5-flash` (#15436)) of packages/google/src/interactions/google-interactions-language-model-options.ts left in tree.
error: could not apply 756fec1... Backport: feat(provider/google): add `gemini-3.5-flash` (#15436)
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
```

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Felix Arntz <felix.arntz@vercel.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: 3 people

.changeset/soft-pillows-shop.md

@@ -0,0 +1,7 @@
+---
+"@ai-sdk/google-vertex": patch
+"@ai-sdk/gateway": patch
+"@ai-sdk/google": patch
+---
+
+feat(provider/google): add `gemini-3.5-flash`

content/providers/01-ai-sdk-providers/15-google-generative-ai.mdx

@@ -1003,6 +1003,7 @@ The following Zod features are known to not work with Google Generative AI:
 
 | Model                                 | Image Input         | Object Generation   | Tool Usage          | Tool Streaming      | Google Search       | URL Context         |
 | ------------------------------------- | ------------------- | ------------------- | ------------------- | ------------------- | ------------------- | ------------------- |
+| `gemini-3.5-flash`                    | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> |
 | `gemini-3.1-pro-preview`              | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> |
 | `gemini-3.1-flash-image-preview`      | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> |
 | `gemini-3-pro-preview`                | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> |

content/providers/01-ai-sdk-providers/16-google-vertex.mdx

@@ -621,6 +621,7 @@ The following Zod features are known to not work with Google Vertex:
 
 | Model                  | Image Input         | Object Generation   | Tool Usage          | Tool Streaming      |
 | ---------------------- | ------------------- | ------------------- | ------------------- | ------------------- |
+| `gemini-3.5-flash`     | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> |
 | `gemini-2.0-flash-001` | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> |
 | `gemini-2.0-flash-exp` | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> |
 | `gemini-1.5-flash`     | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> | <Check size={18} /> |

examples/ai-core/src/generate-text/google-function-call-id.ts

@@ -22,7 +22,7 @@ run(async () => {
 
   // Turn 1: model emits parallel tool calls; tools execute automatically.
   const turn1 = await generateText({
-    model: google('gemini-3-flash-preview'),
+    model: google('gemini-3.5-flash'),
     tools: { weather: weatherTool },
     messages,
     stopWhen: stepCountIs(1),

examples/ai-core/src/generate-text/google-gemini-3-5-flash.ts

@@ -0,0 +1,15 @@
+import { google } from '@ai-sdk/google';
+import { generateText } from 'ai';
+import { run } from '../lib/run';
+
+run(async () => {
+  const result = await generateText({
+    model: google('gemini-3.5-flash'),
+    prompt: 'Invent a new holiday and describe its traditions.',
+  });
+
+  console.log(result.text);
+  console.log();
+  console.log('Token usage:', result.usage);
+  console.log('Finish reason:', result.finishReason);
+});

examples/ai-core/src/stream-text/google-function-call-id.ts

@@ -23,7 +23,7 @@ run(async () => {
 
   // Turn 1: model emits parallel tool calls; tools execute automatically.
   const turn1 = streamText({
-    model: google('gemini-3-flash-preview'),
+    model: google('gemini-3.5-flash'),
     tools: { weather: weatherTool },
     messages,
     stopWhen: stepCountIs(1),

examples/ai-core/src/stream-text/google-gemini-3-5-flash.ts

@@ -0,0 +1,18 @@
+import { google } from '@ai-sdk/google';
+import { streamText } from 'ai';
+import { run } from '../lib/run';
+
+run(async () => {
+  const result = streamText({
+    model: google('gemini-3.5-flash'),
+    prompt: 'Invent a new holiday and describe its traditions.',
+  });
+
+  for await (const textPart of result.textStream) {
+    process.stdout.write(textPart);
+  }
+
+  console.log();
+  console.log('Token usage:', await result.usage);
+  console.log('Finish reason:', await result.finishReason);
+});

packages/gateway/src/gateway-language-model-settings.ts

@@ -63,6 +63,7 @@ export type GatewayModelId =
   | 'google/gemini-3.1-flash-lite'
   | 'google/gemini-3.1-flash-lite-preview'
   | 'google/gemini-3.1-pro-preview'
+  | 'google/gemini-3.5-flash'
   | 'google/gemma-4-26b-a4b-it'
   | 'google/gemma-4-31b-it'
   | 'inception/mercury-2'

packages/google-vertex/src/google-vertex-options.ts

@@ -3,6 +3,7 @@
 // https://console.cloud.google.com/vertex-ai/studio/
 export type GoogleVertexModelId =
   // Stable models
+  | 'gemini-3.5-flash'
   | 'gemini-2.5-pro'
   | 'gemini-2.5-flash'
   | 'gemini-2.5-flash-lite'

packages/google/src/google-generative-ai-options.ts

@@ -44,6 +44,7 @@ export type GoogleGenerativeAIModelId =
   | 'gemini-3.1-flash-image-preview'
   | 'gemini-3.1-flash-lite-preview'
   | 'gemini-3.1-flash-tts-preview'
+  | 'gemini-3.5-flash'
   // latest version
   // https://ai.google.dev/gemini-api/docs/models#latest
   | 'gemini-pro-latest'