Chroma

The Chroma plugin registers retrievers and indexers backed by a Chroma server (v2 REST API) for Retrieval-Augmented Generation.

Installation

<dependency>
    <groupId>com.google.genkit</groupId>
    <artifactId>genkit-plugin-chroma</artifactId>
    <version>1.0.0-SNAPSHOT</version>
</dependency>

Requirements

• A running Chroma server (docker run -p 8000:8000 chromadb/chroma)
• Java 21+
• An embedder (e.g. from the Google GenAI plugin)

Usage

ChromaPlugin registers a retriever and indexer named chroma/<collectionName> for each configured collection.

import com.google.genkit.plugins.chroma.ChromaCollectionConfig;
import com.google.genkit.plugins.chroma.ChromaPlugin;

Genkit genkit = Genkit.builder()
    .plugin(GoogleGenAIPlugin.create(apiKey))
    .plugin(
        ChromaPlugin.builder()
            .url("http://localhost:8000")   // default
            .addCollection(
                ChromaCollectionConfig.builder()
                    .collectionName("films")
                    .embedderName("googleai/gemini-embedding-001")
                    .distance(ChromaCollectionConfig.Distance.COSINE)
                    .createCollectionIfNotExists(true) // default
                    .build())
            .build())
    .build();

// Index and retrieve
genkit.index("chroma/films", documents);
List<Document> results = genkit.retrieve("chroma/films", "a Christopher Nolan sci-fi film");

Configuration

Tune per-collection settings with ChromaCollectionConfig:

• collectionName — the Chroma collection name (required)
• embedderName — the embedder used to vectorize documents and queries (required)
• distance — COSINE (default), L2, or INNER_PRODUCT
• createCollectionIfNotExists — auto-create the collection (default true)
• addAdditionalMetadata(key, value) — metadata merged into every indexed document

Plugin-level tenant and database default to default_tenant / default_database.

Sample

See the chroma sample.