Add Gemini API Support

[evgenyigumnov]

Description:

We need to integrate the Gemini API into our application. Google Gemini API offers free usage with rate limits, making it an attractive option for enhancing our service's capabilities. The API should be used to expand our existing functionality, while ensuring that we respect the rate limits imposed by the API to avoid any disruptions or excessive throttling.

Additional Info:

• Refer to the Gemini API pricing and limits: Google Gemini API Pricing.

[prabirshrestha]

Would you be interested in contribution?

[evgenyigumnov]

1. We plan to add langchain-rust to https://github.com/evgenyigumnov/rustsn
2. I do not know langchain-rust code base and for me more easely add Gemini API directly to Rustsn without langchain-rust

Conclusion: Could any body other implement Gemeini API in langchain project?

[mdabir1203]

I would like to take this issue and contribute to it. May I know in which part of the codebase have you implemented the api connection ?

[prabirshrestha]

Suggest looking in this folder. https://github.com/Abraxas-365/langchain-rust/tree/main/src/llm

[prabirshrestha]

Gemini is now OpenAI compatible which means you can use existing OpenAI libraries including langchain-rust.

https://developers.googleblog.com/en/gemini-is-now-accessible-from-the-openai-library/