Summary

When provider: "gemini" is explicitly configured, use the native Gemini REST adapter (models/{model}:generateContent) for any base_url that doesn't end in /openai — matching how other providers work unconditionally in _create_openai_client().

Gemini was the only provider with a domain-based gate:

Problem

Previously, is_native_gemini_base_url() checked for generativelanguage.googleapis.com in the URL before using the native adapter. With a custom base_url (e.g. a local proxy that speaks Gemini's native REST protocol), the check would fail and silently fall through to the OpenAI-compatible client — sending /v1/chat/completions format instead of /models/{model}:generateContent.

Fix

Replaced the domain-based is_native_gemini_base_url() check with a simpler /openai suffix check:

# Before:
if is_native_gemini_base_url(base_url):  # requires googleapis.com domain

# After:
if not base_url.rstrip('/').lower().endswith('/openai'):  # only skip for OpenAI-compat endpoints

• Any base_url (including custom proxies) → native Gemini adapter
• URLs ending in /openai (e.g. generativelanguage.googleapis.com/v1beta/openai) → OpenAI client (these speak OpenAI format)
• Empty base_url → native adapter (defaults to Google's endpoint internally)

Example config (cli-config.yaml)

model:
  default: "gemini-2.5-flash"
  provider: "gemini"
  base_url: "http://localhost:8900/gemini"
  api_key: "your-proxy-api-key"

Test plan

• Updated test_gemini_custom_base_url to assert native client is used
• test_gemini_openai_compat_base_url_keeps_openai_client unchanged (verifies /openai suffix fallback)
• Verify provider: "gemini" with no base_url still defaults to Google's endpoint
• Verify provider: "gemini" with custom base_url uses native adapter
• Verify other providers are unaffected