You are helping me build the following AI agent workflow.

## Goal
Generate Video From Prompt With Vertex AI: Submit a text prompt to generate a cinematic video via Vertex AI Veo 3 and automatically save the MP4 to your Google Drive.

## Specification
- What it does: Submit a text prompt to instantly generate a cinematic video via Vertex AI Veo 3 and have your finished MP4 automatically saved to Google Drive. You simply provide the prompt and access token through an n8n form trigger to receive the rendered file without manual handling.
- Trigger: Run manually (Manual · on demand via form)
- Autonomy: Fully hands-off
- Expected setup effort: about an afternoon
- Tools/services involved:
  - n8n: Workflow orchestration and HTTP requests
  - Vertex AI Veo 3: Video generation from text prompts
  - Google Drive: Storing the generated video file

## Known pitfalls, handle each one explicitly in your implementation
1. Base64 strings can exceed n8n's default data size limits so you must increase the maxDataSize setting in your workflow configuration.
2. GCP access tokens expire after one hour so add logic to refresh the token if the workflow runs longer than expected.
3. The Google Drive API requires specific scope permissions so verify that the service account has read/write access to the target folder.

## Reference implementation
https://n8n.io/workflows/5228 (workflow template)
Fetch and inspect this before building. If it matches my stack, adapt it;
if not, rebuild the pattern with my tools.

## Process requirements
1. Before building: ask me which of the listed tools I actually use and
   what my platform is (n8n / Make / code / other). Do not assume.
2. Adapt the pattern to my answers; do not force the reference stack.
3. Address every pitfall above; tell me how you handled each.
4. Provide a test plan I can run before letting this touch real data.
5. Ask before any step that sends messages, modifies data, or spends money.

Source: https://usecasesforagents.com/use-case/generate-video-from-prompt-with-vertex-ai/ via usecasesforagents.com