# gemini-2.5-flash-lite-preview-09-2025

Calls to the model gemini-2.5-flash-lite-preview-09-2025 on Vertex AI stopped working on July 9, 2026.

On July 9, 2026, Vertex AI retired model gemini-2.5-flash-lite-preview-09-2025. The endpoint is no longer accessible, and requests sent to this model fail since that day. This change affects any calls targeting the preview model identifier.

## The error Vertex AI returns once gemini-2.5-flash-lite-preview-09-2025 is gone

HTTP 404

```json
{"error":{"code":404,"message":"Publisher model `projects/{project}/locations/{region}/publishers/google/models/gemini-2.5-flash-lite-preview-09-2025` was not found or your project does not have access to it. Ensure you are using a valid model name and that the model is available in the specified region.","status":"NOT_FOUND"}}
```

## What to use instead

See Migrate to the latest Google models for information on how to migrate your project.

- API: Vertex AI (aiplatform.googleapis.com)
- Model: gemini-2.5-flash-lite-preview-09-2025
- Released: September 25, 2025 (models.dev)
- Kind: Model retirement
- Announced: July 9, 2026
- Takes effect: July 9, 2026
- Calls after that day: fail
- Calls it hits: `model gemini-2.5-flash-lite-preview-09-2025`
- Source: [Changelog](https://docs.cloud.google.com/gemini-enterprise-agent-platform/release-notes)
- Verified: November 6, 2026, against Vertex AI's own pages
- Page: https://www.okapi.bot/models/vertex-ai/gemini-2.5-flash-lite-preview-09-2025/

## Vertex AI's words

> The following preview model endpoints have been retired and are no longer accessible:
> 
> - gemini-2.5-flash-lite-preview-09-2025
> - gemini-2.5-flash-preview-05-2025
> - gemini-3.1-flash-lite-preview

Okapi finds the calls this change hits in your repo and opens the pull request with the fix: https://github.com/apps/okapi-agent