fix(embeddings): allow dimensions param passthrough via allowed_openai_params for non-text-embedding-3 OpenAI models

[Sameerlite]

When calling non-text-embedding-3 models routed through the openai provider (e.g. nvidia/llama-3.2-nv-embedqa-1b-v2), passing dimensions previously raised an UnsupportedParamsError unconditionally. This fix threads allowed_openai_params through the embedding call stack so that providers can opt-in to passing dimensions by including it in the list.

Relevant issues

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Type

🆕 New Feature
🐛 Bug Fix
🧹 Refactoring
📖 Documentation
🚄 Infrastructure
✅ Test

Changes

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Project	Deployment	Actions	Updated (UTC)
litellm	Ready	Preview, Comment	Feb 26, 2026 4:34am

[greptile-apps]

Greptile Summary

This PR adds an allowed_openai_params passthrough mechanism to the embedding call stack, allowing non-text-embedding-3 OpenAI models (e.g., nvidia/llama-3.2-nv-embedqa-1b-v2) to accept the dimensions parameter without raising UnsupportedParamsError. The change is minimal and well-scoped.

• litellm/main.py: Extracts allowed_openai_params from kwargs and passes it to get_optional_params_embeddings
• litellm/utils.py: Adds allowed_openai_params parameter to skip the dimensions restriction when the param is explicitly allowed
• Tests added in tests/local_testing/ covering both the allow and reject paths
• Note: The PR adds tests only in tests/local_testing/, not in tests/litellm/ as required by the contribution checklist
• The pre-existing error message on line 3202 is misleading (says "not supported for text-embedding-3" when it should say "only supported for text-embedding-3")

Confidence Score: 4/5

• This PR is safe to merge — it adds a non-breaking opt-in bypass for a parameter restriction with proper guard conditions.
• The change is minimal and backwards-compatible. The existing behavior is preserved when allowed_openai_params is not passed. Tests cover both the happy path and the error path. Minor issues: a leftover debug log and a pre-existing misleading error message.
• litellm/utils.py has a debug log that should be removed before merge

Important Files Changed

Filename	Overview
litellm/main.py	Extracts allowed_openai_params from kwargs and passes it through to get_optional_params_embeddings. Clean, minimal change.
litellm/utils.py	Adds allowed_openai_params parameter to get_optional_params_embeddings and uses it to bypass the dimensions check for non-text-embedding-3 OpenAI models. Contains a debug log that should be removed and a pre-existing misleading error message.
tests/local_testing/test_get_optional_params_embeddings.py	Adds two unit tests: one verifying dimensions passes through with allowed_openai_params, one verifying it still raises without. Tests are well-structured but placed in tests/local_testing/ rather than the required tests/litellm/ directory.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["embedding() in main.py"] --> B["Extract allowed_openai_params from kwargs"]
    B --> C["Call get_optional_params_embeddings()"]
    C --> D{"custom_llm_provider == 'openai'?"}
    D -- No --> E["Other provider handling"]
    D -- Yes --> F{"model contains 'text-embedding-3'?"}
    F -- Yes --> G["Pass all non_default_params through"]
    F -- No --> H{"'dimensions' in non_default_params?"}
    H -- No --> G
    H -- Yes --> I{"'dimensions' in allowed_openai_params?"}
    I -- Yes --> G
    I -- No --> J["Raise UnsupportedParamsError"]

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_{Last reviewed commit: 3634b5f}

[greptile-apps]

_{3 files reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

Debug log should be removed

This verbose_logger.debug call logs the allowed_openai_params value on every OpenAI embedding call. While not harmful, it appears to be a leftover debugging statement. Consider removing it before merging.

Suggested change

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[greptile-apps]

Additional Comments (1)

litellm/utils.py
Pre-existing: misleading error message

The error message says "Setting dimensions is not supported for OpenAI text-embedding-3 and later models" — but the condition triggers for models that are not text-embedding-3. The message should say something like "Setting dimensions is only supported for OpenAI text-embedding-3 and later models" (note: "only supported for" instead of "not supported for"). This bug predates this PR but is worth fixing here since you're already modifying this block.

            raise UnsupportedParamsError(
                status_code=500,
                message="Setting dimensions is only supported for OpenAI `text-embedding-3` and later models. To drop it from the call, set `litellm.drop_params = True`.",
            )