[Bug]: OpenRouter model selected from Admin UI list fails Test Connect with 'is not a valid model ID'

[Sunsilkk]

What happened?

In LiteLLM Admin UI, when adding a model with provider OpenRouter, I selected openrouter/google/gemini-2.5-flash directly from the provider model list/dropdown.

When I click Test Connect, the request fails with:

OpenrouterException - {"error":{"message":"openrouter/google/gemini-2.5-flash is not a valid model ID","code":400},"user_id":"..."}

This does not appear to be a manual input error, because the model was selected from the OpenRouter model list in the UI.

Why this seems incorrect

As of March 30, 2026, google/gemini-2.5-flash still exists on OpenRouter:
https://openrouter.ai/google/gemini-2.5-flash

So either:

1. LiteLLM Admin UI is surfacing a stale or invalid OpenRouter model ID.
2. The Test Connect flow is sending a model name format that OpenRouter rejects.
3. There is a mismatch between what the dropdown returns and what the backend/OpenRouter expects.

Reproduction

1. Open LiteLLM Admin UI.
2. Go to Models + Endpoints -> Add Model.
3. Choose provider: OpenRouter.
4. Select model from the provider model list: openrouter/google/gemini-2.5-flash.
5. Click Test Connect.

Actual result

Connection test fails with:

OpenrouterException - {"error":{"message":"openrouter/google/gemini-2.5-flash is not a valid model ID","code":400}}

Expected result

If the model is selectable from the OpenRouter list, Test Connect should succeed, or the UI should not offer that model.

API request shown by the UI

curl -X POST \
  https://openrouter.ai/api/v1/chat/completions \
  -H 'HTTP-Referer: https://litellm.ai' \
  -H 'X-Title: LiteLLM' \
  -H 'Authorization: Bearer <redacted>' \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "openrouter/google/gemini-2.5-flash",
    "messages": [
      {
        "role": "user",
        "content": "hello"
      }
    ]
  }'

Environment

• LiteLLM version: v1.82.3
• Provider: OpenRouter
• Flow: Admin UI -> Add Model -> select from list -> Test Connect

Notes

This looks related to earlier OpenRouter model ID issues, but this specific bug is about a model selected directly from the Admin UI list still failing validation.

[alexsmirnov]

The same with other models. This is regression bug: litellm sends full model reference with provider name: openrouter/google/gemini-2.5-flash instead of openrouter id google/gemini-2.5-flash

[dan-and]

Same issue on my side.

Suggested label: bug

[dan-and]

@Sunsilkk & @alexsmirnov , the current code does fix the issue, but that is not released for now.

If you are using docker compose and you need a quick fix: clone the repository (add your .env and docker-compose.yml) and run:
docker compose up -d --build

[aibill2029]

@Sunsilkk & @alexsmirnov , the current code does fix the issue, but that is not released for now.

If you are using docker compose and you need a quick fix: clone the repository (add your .env and docker-compose.yml) and run: docker compose up -d --build

I did pull the latest repo, and use the .env.example -> .env and docker-compose.yml in the latest repo, but the problem still exists, why?

[developweblink]

but is it so hard to fix this bug?

[kabo]

I pulled latest image (v.83.10) and it seems to be working fine

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.