> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lancedb.com/llms.txt
> Use this file to discover all available pages before exploring further.

# OpenAI

Embed text and generate completions using OpenAI models.
See the [API reference](https://lancedb.github.io/geneva/api/openai/) for all parameters.

```python theme={"theme":{"light":"vitesse-light","dark":"catppuccin-mocha"}}
pip install 'geneva[udf-text-openai]'
```

<Warning>
  OpenAI UDFs make API calls that incur **per-token costs**. Each row processed results in one
  or more API requests billed to your account. Review
  [OpenAI pricing](https://openai.com/api/pricing/) before running on large tables.
</Warning>

<Note>
  Set the `OPENAI_API_KEY` environment variable before calling any factory function below.
  The key is read **at UDF creation time** and serialized with the UDF — no cluster-level
  `env_vars` configuration is needed.
</Note>

## Embeddings

**Compare models by adding multiple embedding columns at once:**

```python theme={"theme":{"light":"vitesse-light","dark":"catppuccin-mocha"}}
from geneva.udfs import openai_embedding_udf

table.add_columns({
    # Default model — fast, 1536 dimensions
    "embedding_small": openai_embedding_udf(
        column="body",
        model="text-embedding-3-small",
    ),
    # Higher-quality model — 3072 dimensions
    "embedding_large": openai_embedding_udf(
        column="body",
        model="text-embedding-3-large",
    ),
    # Same large model, truncated to 256 dimensions for storage efficiency
    "embedding_large_256": openai_embedding_udf(
        column="body",
        model="text-embedding-3-large",
        output_dimensionality=256,
    ),
})
```

## Generation

Generate text from OpenAI chat completion models. Supports both text and binary (image)
input columns.
See the [API reference](https://lancedb.github.io/geneva/api/openai/#geneva.udfs.openai.openai_udf) for all parameters.

**Add a summary and an image caption in one call, using different models:**

```python theme={"theme":{"light":"vitesse-light","dark":"catppuccin-mocha"}}
from geneva.udfs import openai_udf

table.add_columns({
    # Fast model for bulk text summarization
    "summary": openai_udf(
        column="body",
        prompt="Summarize this document in 3 bullet points",
        model="gpt-5-mini",
    ),
    # More capable model for nuanced image captions
    "caption": openai_udf(
        column="image",
        prompt="Provide a 1 sentence description of the scene",
        model="gpt-5",
        mime_type="image/jpeg",
    ),
})
```

## API Reference

* [OpenAI](https://lancedb.github.io/geneva/api/openai/) — `openai_udf()` and `openai_embedding_udf()` — all parameters including `column`, `prompt`, `model`, `mime_type`, `dimensions`, and `normalize`