feat: add support for new Veo 3.1 models in Vertex AI provider

[dhvll]

Add support for Google Vertex AI Veo 3.1 video models to Echo router and Next.js video template.
Set Veo 3.1 as the default in the template.
Resolves: #595

[vercel]

@dhvll is attempting to deploy a commit to the Merit Systems Team on Vercel.

A member of the Team first needs to authorize it.

[vercel]

Additional Comments:

templates/next-video-template/src/app/api/generate-video/validation.ts (lines 37-40):
The validation file was not updated to include the new veo-3.1 models, which will cause the API to reject all requests using the newly added veo-3.1 models even though they are now in the UI dropdown.

View Details

📝 Patch Details

diff --git a/templates/next-video-template/src/app/api/generate-video/validation.ts b/templates/next-video-template/src/app/api/generate-video/validation.ts
index 669dfd41..16639b8d 100644
--- a/templates/next-video-template/src/app/api/generate-video/validation.ts
+++ b/templates/next-video-template/src/app/api/generate-video/validation.ts
@@ -35,6 +35,8 @@ export function validateGenerateVideoRequest(body: unknown): ValidationResult {
   }
 
   const validModels: VideoModelOption[] = [
+    'veo-3.1-fast-generate-preview',
+    'veo-3.1-generate-preview',
     'veo-3.0-fast-generate-preview',
     'veo-3.0-generate-preview',
   ];

Analysis

API validation rejects veo-3.1 models that are available in UI

What fails: validateGenerateVideoRequest() in validation.ts only allows veo-3.0 models, rejecting veo-3.1 models that are available in the UI dropdown

How to reproduce:

# Send API request with veo-3.1 model:
curl -X POST /api/generate-video -H "Content-Type: application/json" \
  -d '{"prompt":"test video","model":"veo-3.1-fast-generate-preview"}'

Result: Returns 400 error: "Model must be: veo-3.0-fast-generate-preview, veo-3.0-generate-preview"

Expected: Should accept veo-3.1 models since they're defined in VideoModelOption type and available in video-generator.tsx UI component

[dhvll]

@zdql can I get review on this?

[dhvll]

Can I get a review on this @rsproule

[rsproule]

can you add this option in the next video template?

how did you test this?

[dhvll]

Haven’t tested the old and new models yet — just updated the latest models according to the pricing changes.

[rsproule]

Easiest way to test is probably to update the video template with these new model options + point it at your local version of echo

[dhvll]

Okay on it