Is it possible to write a tool to build vectors (embedding) yourself?

Hello!

We are creating a Q&A service that uses embedding for local search and for Turbo 3.5 answer generation

We need advice on what tool to use to build vectors without using OpenAI.

Is it possible to write a tool to build vectors (embedding) yourself.

What is better to use to build vectors: full-text context search or text search by vectors (embedding)