# get_base_url_env_var

> **Function** in `deepagents_code`

📖 [View in docs](https://reference.langchain.com/python/deepagents-code/model_config/get_base_url_env_var)

Return the canonical base-URL env var name for a provider.

Checks the config file's `base_url_env` first (user override), then falls
back to the canonical name in the hardcoded `PROVIDER_BASE_URL_ENV` map.
Parallel to `get_credential_env_var`.

## Signature

```python
get_base_url_env_var(
    provider: str,
) -> str | None
```

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| `provider` | `str` | Yes | Provider name. |

## Returns

`str | None`

Environment variable name, or None if the provider has no base-URL env

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[View source on GitHub](https://github.com/langchain-ai/deepagents/blob/e14e0adcbe78565ed3650e7f24b2a775d5437d25/libs/code/deepagents_code/model_config.py#L2152)