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Ollama

https://ollama.com/

Maven Dependency​

<dependency>
    <groupId>dev.langchain4j</groupId>
    <artifactId>langchain4j-ollama</artifactId>
    <version>1.17.2</version>
</dependency>

APIs​

  • OllamaEmbeddingModel

Usage​

EmbeddingModel embeddingModel = OllamaEmbeddingModel.builder()
    .baseUrl("http://localhost:11434")
    .modelName("all-minilm")
    .build();

Response<Embedding> response = embeddingModel.embed("Hello, world!");
Embedding embedding = response.content();

Request/response API and observability​

OllamaEmbeddingModel supports embed(EmbeddingRequest) in addition to the convenience methods. Ollama's embedding API is text-only, so a request that sets an input type or an image input fails fast with UnsupportedFeatureException. Token usage (prompt_eval_count) is reported in the response metadata.

Ollama's optional output dimensions is model-dependent (only some models support reducing the output size), so it is configured on the builder via .dimensions(...) rather than as a per-call parameter.

Attach listeners to observe requests, responses, and errors:

EmbeddingModel embeddingModel = OllamaEmbeddingModel.builder()
    .baseUrl("http://localhost:11434")
    .modelName("all-minilm")
    .listeners(List.of(myEmbeddingModelListener))
    .build();

Examples​