fix(cost-map): add us-south1 to vertex qwen3-235b-a22b-instruct-2507-maas

[ti3x]

Refs #25380

Summary

Add us-south1 to supported_regions for the Vertex Qwen model:

vertex_ai/qwen/qwen3-235b-a22b-instruct-2507-maas

This updates both:

• model_prices_and_context_window.json
• litellm/model_prices_and_context_window_backup.json

Why

LiteLLM's packaged metadata currently lists only:

["global"]

for this model.

When LiteLLM is configured to use this Vertex Qwen model in us-south1, it warns that the region is unsupported and routes to global instead.

Observed warning:

Vertex AI model 'qwen/qwen3-235b-a22b-instruct-2507-maas' does not support region 'us-south1' (supported: ['global']). Routing to 'global'.

I also verified the packaged metadata inside the latest Docker image:

ghcr.io/berriai/litellm:main-stable

and it currently reports:

["global"]

for this model's supported_regions.

What changed

Added us-south1 to:

  "vertex_ai/qwen/qwen3-235b-a22b-instruct-2507-maas": {
    "supported_regions": [
      "global",
      "us-south1"
    ]
  }

Validation

This matches working behavior against Vertex AI for the same model in us-south1.

As a local workaround before this patch, overriding LiteLLM's cost map to add us-south1 removed the warning and allowed the expected us-south1 configuration to work correctly.

[vercel]

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Project	Deployment	Actions	Updated (UTC)
litellm	Ready	Preview, Comment	Apr 8, 2026 11:47pm

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[greptile-apps]

Greptile Summary

This PR adds "us-south1" to the supported_regions list for vertex_ai/qwen/qwen3-235b-a22b-instruct-2507-maas in both the primary and backup model pricing JSON files, fixing a routing warning that caused requests targeting us-south1 to fall back to global. Both files are updated consistently and no other metadata fields are affected.

Confidence Score: 5/5

Safe to merge — minimal, targeted metadata fix with no code logic changes.

Both JSON files are updated consistently; the change is a one-line addition to a supported_regions array. No logic, no tests, no schema, no security surface affected.

No files require special attention.

Vulnerabilities

No security concerns identified.

Important Files Changed

Filename	Overview
model_prices_and_context_window.json	Adds "us-south1" to supported_regions for vertex_ai/qwen/qwen3-235b-a22b-instruct-2507-maas; no other fields changed.
litellm/model_prices_and_context_window_backup.json	Mirror of the primary JSON change — adds "us-south1" to the same model's supported_regions; kept in sync with model_prices_and_context_window.json.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["LiteLLM receives request\nfor vertex_ai/qwen/qwen3-235b-a22b-instruct-2507-maas\nregion: us-south1"] --> B{"Is us-south1 in\nsupported_regions?"}
    B -- "Before fix: NO" --> C["⚠️ Warning: region unsupported\nRoutes to 'global' instead"]
    B -- "After fix: YES" --> D["✅ Routes to us-south1\nas configured"]

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_{Reviews (1): Last reviewed commit: "fix(cost-map): add us-south1 to vertex q..." | Re-trigger Greptile}

[codspeed-hq]

Merging this PR will not alter performance

✅ 16 untouched benchmarks

---

_{Comparing ti3x:txia/qwen3-us-south1-cost-map (b987bc5) with main (072d410)}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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