Regional Availability Conflict: Gemini 3 (global) vs Mistral OCR (regional) in Vertex AI

[falkenbt]

Problem Description

I'm currently using Google Vertex AI to access models in LibreChat with the following setup:

• Gemini 3 model for conversational AI (only available in the global region)
• Mistral OCR model for document processing in the RAG API (only available in non-global regions, specifically us-central1)

The Issue

The current LibreChat architecture allows only a single, centralized location to be specified for all Google Vertex AI models via the GOOGLE_LOC environment variable. This setting applies globally to all Vertex AI endpoints and operations.

This creates a blocker: I can either:

1. Set GOOGLE_LOC=global to use Gemini 3 → OCR/Mistral functionality breaks (Mistral OCR is not available in the global region)
2. Set GOOGLE_LOC=us-central1 (or another non-global region) to use Mistral OCR → Gemini 3 becomes unavailable (Gemini 3 is only available in the global region)

Environment Details

• LibreChat Configuration: Using Vertex AI endpoint with Google authentication
• Models:
  • Gemini 2.5 Flash (works in any region)
  • Gemini 3 (only in global)
  • Mistral OCR 2505 (only in non-global regions like us-central1)
• Current Workaround: None available

Questions for the Community

1. Has anyone else encountered this regional availability conflict when using multiple Vertex AI models?
2. Are there any workarounds or solutions I might have missed?
3. Would it be feasible to extend the configuration to support per-model or per-endpoint region specification instead of a global setting?
4. Are there alternative OCR strategies available that work in the global region?

Suggested Solution Direction

A potential enhancement could allow more granular region configuration, such as:

endpoints:
  google:
    defaultLocation: "global"
    modelRegionOverrides:
      "gemini-3": "global"
      "mistral-ocr-2505": "us-central1"

ocr:
  mistralModel: "mistral-ocr-2505"
  location: "us-central1"  # Override default location
  strategy: "vertexai_mistral_ocr"

Any suggestions or guidance would be greatly appreciated! 🙏

[falkenbt]

Still hoping for some guidence here :)

[yooknee]

I also ran into this, would be cool to be able to set different regions for different models.