[FEATURE]: Support LLM Gateway as a built-in provider

[smakosh]

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Add support for an open-source OpenRouter alternative: https://llmgateway.io

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• [Feature Request] Support traditional Chat Completions API for OpenAI provider #7793: Support traditional Chat Completions API for OpenAI provider - discusses compatibility with OpenAI-compatible proxies
• [FEATURE]: Add codex-compatible/claudecode-compatible provider #7728: Add codex-compatible/claudecode-compatible provider - related feature request for alternative provider support
• [BUG] Custom provider initialization fails with "fn3 is not a function #7792: Custom provider initialization fails - discusses custom provider configuration issues
• Support OpenRouter OAuth PKCE authentication #7766: Support OpenRouter OAuth PKCE authentication - OpenRouter-specific authentication enhancement

While #7848 is specifically about LLMGateway.io support, these related issues discuss broader provider compatibility and custom provider infrastructure that may be relevant.

Feel free to ignore if this is addressing a completely different aspect of LLMGateway support.

[thdxr]

To stay organized issues are automatically closed after 90 days of no activity. If the issue is still relevant please open a new one.