EmbeddingsProvider

EmbeddingsProvider is the capability trait for vector embeddings. Implement it and your provider can power the embeddings builder state.

The trait

#[async_trait]
pub trait EmbeddingsProvider: Send + Sync {
    async fn embed(&self, messages: &mut Messages) -> Result<EmbeddingsResponse, ChatFailure>;
}

embed takes the messages to encode and returns an EmbeddingsResponse. Note it borrows &self, not &mut self: embedding does not mutate provider state the way a completion step can.

A minimal implementation

use async_trait::async_trait;

struct MyEmbedder;

#[async_trait]
impl EmbeddingsProvider for MyEmbedder {
    async fn embed(&self, messages: &mut Messages) -> Result<EmbeddingsResponse, ChatFailure> {
        todo!()
    }
}

Reaching it from the builder

Embeddings are a builder state. Call .with_embeddings() to move into the Embedded state, then .embed(...) on the resulting Chat:

let chat = ChatBuilder::new()
    .with_model(MyEmbedder)
    .with_embeddings()
    .build();

let response = chat.embed(&mut messages).await?;

The Embedded state only exposes embed, so the type system keeps embedding and completion flows from getting tangled. For the full walkthrough, including what EmbeddingsResponse carries, see Capabilities: Embeddings.