get_base_url

Get the configured base URL for a provider.

Resolution order (first match wins):

1. base_url in the provider's config.toml section.
2. The provider's base-URL env vars via resolve_env_var, in provider precedence order, so DEEPAGENTS_CODE_{VAR} beats the plain {VAR} for each name — mirroring how API keys resolve. This also surfaces the value apply_stored_credentials bridged in from a /auth credential, and the gateway-provisioned URL in the default (no-override) case.
3. The endpoint stored with a /auth credential. This is the source for providers that have no base-URL env var (e.g. an OpenAI- compatible provider like Litellm): step 2 has no name to read, so the stored endpoint is taken directly. It then reaches the model as the base_url constructor kwarg via _get_provider_kwargs, the same path a config.toml literal uses. For providers that do have an env var, the stored endpoint already arrives via step 2 (it was bridged onto the env var), so this step is a redundant — and consistent — fallback.

This function only resolves the endpoint; whether it takes effect is a separate contract owned by the provider's LangChain class. The value is delivered as the base_url kwarg (see _get_provider_kwargs), which the OpenAI/Anthropic-compatible classes accept via a Pydantic base_url alias. A class that names the field differently may silently ignore base_url — Pydantic models default to extra="ignore" — so for those the endpoint must be set via params.

A corrupt credential store is treated as "no stored endpoint" rather than propagating, so endpoint resolution never newly raises.