chroma

Chroma Go

A simple Chroma Vector Database client written in Go. Current chroma-go release lines (v0.3.x and v0.4.x) are compatible with Chroma v1.x. For older Chroma versions, use older chroma-go releases (for example v0.2.x). See compatibility.

[!WARNING] V1 API Removed: The V1 API is removed in v0.3.x and later releases. If you require V1 API compatibility, please use versions prior to v0.3.0 (for example v0.2.x).

go get github.com/amikos-tech/chroma-go@v0.2.4

We invite users to visit the docs site for the library for more in-depth information: Chroma Go Docs

Compatibility

• chroma-go v0.3.x and v0.4.x are compatible with Chroma v1.x.
• For older Chroma versions, use older chroma-go release lines (for example v0.2.x).
• Older client versions: GitHub Releases

Installation

go get github.com/amikos-tech/chroma-go

Import:

import (
	chroma "github.com/amikos-tech/chroma-go/pkg/api/v2"
)

Quick Start

Persistent Client

Run Chroma locally in-process (no external server) with NewPersistentClient. The runtime auto-downloads the correct shim library on first use and caches it under ~/.cache/chroma/local_shim. Override with CHROMA_LIB_PATH or WithPersistentLibraryPath(...).

package main

import (
	"context"
	"fmt"
	"log"

	chroma "github.com/amikos-tech/chroma-go/pkg/api/v2"
)

func main() {
	client, err := chroma.NewPersistentClient(
		chroma.WithPersistentPath("./chroma_data"),
	)
	if err != nil {
		log.Fatalf("Error creating client: %s", err)
	}
	defer client.Close()

	col, err := client.GetOrCreateCollection(context.Background(), "my_collection")
	if err != nil {
		log.Fatalf("Error creating collection: %s", err)
	}

	err = col.Add(context.Background(),
		chroma.WithIDs("1", "2"),
		chroma.WithTexts("hello world", "goodbye world"),
	)
	if err != nil {
		log.Fatalf("Error adding documents: %s", err)
	}

	qr, err := col.Query(context.Background(),
		chroma.WithQueryTexts("say hello"),
		chroma.WithNResults(1),
		chroma.WithInclude(chroma.IncludeDocuments),
	)
	if err != nil {
		log.Fatalf("Error querying: %s", err)
	}
	fmt.Printf("Result: %v\n", qr.GetDocumentsGroups()[0][0])
}

Full runnable example: examples/v2/persistent_client

Self-Hosted (HTTP)

Connect to a Chroma server running on http://localhost:8000:

docker run -d --name chroma -p 8000:8000 -e ALLOW_RESET=TRUE chromadb/chroma:latest

Then create the client (default Chroma URL: http://localhost:8000):

package main

import (
	"context"
	"fmt"
	"log"

	chroma "github.com/amikos-tech/chroma-go/pkg/api/v2"
)

func main() {
	client, err := chroma.NewHTTPClient(
		chroma.WithBaseURL("http://localhost:8000"),
	)
	if err != nil {
		log.Fatalf("Error creating client: %s", err)
	}
	defer client.Close()

	col, err := client.GetOrCreateCollection(context.Background(), "my_collection")
	if err != nil {
		log.Fatalf("Error creating collection: %s", err)
	}

	err = col.Add(context.Background(),
		chroma.WithIDs("1", "2"),
		chroma.WithTexts("hello world", "goodbye world"),
	)
	if err != nil {
		log.Fatalf("Error adding documents: %s", err)
	}

	qr, err := col.Query(context.Background(),
		chroma.WithQueryTexts("say hello"),
		chroma.WithNResults(1),
		chroma.WithInclude(chroma.IncludeDocuments),
	)
	if err != nil {
		log.Fatalf("Error querying: %s", err)
	}
	fmt.Printf("Result: %v\n", qr.GetDocumentsGroups()[0][0])
}

Stop the local container when done: docker stop chroma && docker rm chroma. Alternative local startup helper: make server (requires Docker). See the official documentation for other deployment options.

Chroma Cloud

Connect to Chroma Cloud using your API key:

package main

import (
	"context"
	"fmt"
	"log"
	"os"

	chroma "github.com/amikos-tech/chroma-go/pkg/api/v2"
)

func main() {
	client, err := chroma.NewCloudClient(
		chroma.WithCloudAPIKey(os.Getenv("CHROMA_API_KEY")),
		chroma.WithDatabaseAndTenant(
			os.Getenv("CHROMA_DATABASE"),
			os.Getenv("CHROMA_TENANT"),
		),
	)
	if err != nil {
		log.Fatalf("Error creating client: %s", err)
	}
	defer client.Close()

	col, err := client.GetOrCreateCollection(context.Background(), "my_collection")
	if err != nil {
		log.Fatalf("Error creating collection: %s", err)
	}

	fmt.Printf("Collection: %s\n", col.Name())
}

Full auth example: examples/v2/auth

Examples

Offline / Air-Gapped Environments

The default embedding function and persistent client runtime require native libraries that are normally downloaded on first use. For offline or air-gapped environments, pre-download all runtime dependencies:

./scripts/fetch_runtime_deps.sh

Then run the offline smoke test to verify:

make offline-smoke

See Offline Runtime Bundle for full details and available flags.

Feature Parity with ChromaDB API

Additional support features:

• ✅ Authentication (Basic, Token with Authorization header, Token with X-Chroma-Token header)
• ✅ Private PKI and self-signed certificate support
• ✅ Chroma Cloud support
• ✅ Structured Logging - Injectable logger with Zap bridge for structured logging
• ✅ Persistent Embedding Function support - automatically load embedding function from Chroma collection configuration
• ✅ Persistent Client support - Run/embed full-featured Chroma in your Go application without running an external Chroma server process.
• ✅ Search API Support
• ✅ Array Metadata support with $contains/$not_contains operators (Chroma >= 1.5.0)

Embedding API and Models Support

• ✅ Default Embedding Support - the default all-MiniLM-L6-v2 model running on Onnx Runtime (ORT).
• ✅ Offline Runtime Setup Script - download and cache default embedding runtime files locally before running smoke/offline workflows.
• ✅ OpenAI Embedding Support
• ✅ Cohere (including Multi-language support)
• ✅ Sentence Transformers (HuggingFace Inference API and HFEI local server)
• ✅ Google Gemini Embedding Support
• ✅ HuggingFace Embedding Inference Server Support
• ✅ Ollama Embedding Support
• ✅ Cloudflare Workers AI Embedding Support
• ✅ Together AI Embedding Support
• ✅ Voyage AI Embedding Support
• ✅ Mistral AI API Embedding Support
• ✅ Nomic AI Embedding Support
• ✅ Jina AI Embedding Support
• ✅ Roboflow CLIP Embedding Support (Multimodal: text + images)
• ✅ Amazon Bedrock Embedding Support (Titan models, bearer token + SDK auth)
• ✅ Baseten Embedding Support
• ✅ Morph Embedding Support
• ✅ Perplexity Embedding Support

Sparse & Specialized Embedding Functions:

• ✅ Chroma Cloud Embedding Support
• ✅ Chroma Cloud Splade Embedding Support (sparse)
• ✅ BM25 Embedding Support (sparse)

Reranking Functions

The Chroma Go client supports Reranking functions:

• ✅ Cohere
• ✅ Jina AI
• ✅ HuggingFace Embedding Inference Server Reranker
• ✅ Together AI

Schema Quickstart

// NewSchemaWithDefaults (L2 + HNSW defaults)
schema, err := chroma.NewSchemaWithDefaults()
if err != nil {
	panic(err)
}

// Custom schema: vector + FTS + metadata indexes
schema, err := chroma.NewSchema(
	chroma.WithDefaultVectorIndex(chroma.NewVectorIndexConfig(
		chroma.WithSpace(chroma.SpaceCosine),
		chroma.WithHnsw(chroma.NewHnswConfig(
			chroma.WithEfConstruction(200),
			chroma.WithMaxNeighbors(32),
		)),
	)),
	chroma.WithDefaultFtsIndex(&chroma.FtsIndexConfig{}),
	chroma.WithStringIndex("category"),
	chroma.WithIntIndex("year"),
	chroma.WithFloatIndex("rating"),
)
if err != nil {
	panic(err)
}

// Disable an index for one field
schema, err := chroma.NewSchema(
	chroma.WithDefaultVectorIndex(chroma.NewVectorIndexConfig(chroma.WithSpace(chroma.SpaceL2))),
	chroma.DisableStringIndex("large_text_field"),
)
if err != nil {
	panic(err)
}

// SPANN (Chroma Cloud)
schema, err := chroma.NewSchema(
	chroma.WithDefaultVectorIndex(chroma.NewVectorIndexConfig(
		chroma.WithSpace(chroma.SpaceCosine),
		chroma.WithSpann(chroma.NewSpannConfig(
			chroma.WithSpannSearchNprobe(64),
			chroma.WithSpannEfConstruction(200),
		)),
	)),
)
if err != nil {
	panic(err)
}

Runnable schema example: examples/v2/schema

Strict Metadata Map Validation

When metadata comes from map[string]interface{}:

• NewMetadataFromMap is best-effort and silently skips invalid []interface{} values.
• NewMetadataFromMapStrict returns an error for invalid or unsupported values.
• WithCollectionMetadataMapCreateStrict applies strict conversion in create/get-or-create flows and returns a deferred option error before any HTTP request is sent.

// Strict create/get-or-create metadata map conversion
col, err := client.GetOrCreateCollection(context.Background(), "col1",
	chroma.WithCollectionMetadataMapCreateStrict(map[string]interface{}{
		"description": "validated metadata",
		"tags":        []interface{}{"a", "b"},
	}),
)
if err != nil {
	log.Fatalf("Error creating collection: %s", err)
}

// Strict metadata map conversion before collection metadata update
newMetadata, err := chroma.NewMetadataFromMapStrict(map[string]interface{}{
	"description": "updated description",
	"tags":        []interface{}{"x", "y"},
})
if err != nil {
	log.Fatalf("Invalid metadata map: %s", err)
}
if err := col.ModifyMetadata(context.Background(), newMetadata); err != nil {
	log.Fatalf("Error modifying metadata: %s", err)
}

Unified Options API

The V2 API provides a unified options pattern where common options work across multiple operations:

// Get documents by ID or filter
results, _ := col.Get(ctx,
chroma.WithIDs("id1", "id2"),
chroma.WithWhere(chroma.EqString("status", "active")),
chroma.WithInclude(chroma.IncludeDocuments, chroma.IncludeMetadatas),
)

// Query with semantic search
results, _ := col.Query(ctx,
chroma.WithQueryTexts("machine learning"),
chroma.WithWhere(chroma.GtInt("year", 2020)),
chroma.WithNResults(10),
)

// Delete by filter
_ = col.Delete(ctx, chroma.WithWhere(chroma.EqString("status", "archived")))

// Search API with ranking and pagination
results, _ := col.Search(ctx,
chroma.NewSearchRequest(
chroma.WithKnnRank(chroma.KnnQueryText("query")),
chroma.WithFilter(chroma.EqString(chroma.K("category"), "tech")),
chroma.NewPage(chroma.Limit(20)),
chroma.WithSelect(chroma.KDocument, chroma.KScore),
),
)

Structured Logging

The client supports injectable loggers for structured logging. Here's a quick example using Zap:

package main

import (
	"context"
	"log"

	"go.uber.org/zap"
	chromalogger "github.com/amikos-tech/chroma-go/pkg/logger"
	chroma "github.com/amikos-tech/chroma-go/pkg/api/v2"
)

func main() {
	// Create a zap logger
	zapLogger, _ := zap.NewDevelopment()
	defer zapLogger.Sync()

	// Wrap it in the Chroma logger
	logger := chromalogger.NewZapLogger(zapLogger)

	// Create client with the logger
	client, err := chroma.NewHTTPClient(
		chroma.WithBaseURL("http://localhost:8000"),
		chroma.WithLogger(logger),
	)
	if err != nil {
		log.Fatal(err)
	}
	defer client.Close()

	// All client operations will now be logged with structured logging
	ctx := context.Background()
	collections, _ := client.ListCollections(ctx)

	// You can also log directly
	logger.Info("Retrieved collections",
		chromalogger.Int("count", len(collections)),
	)

	// For debug logging, use WithLogger with a debug-level logger
	devLogger, _ := chromalogger.NewDevelopmentZapLogger()
	debugClient, _ := chroma.NewHTTPClient(
		chroma.WithBaseURL("http://localhost:8000"),
		chroma.WithLogger(devLogger),
	)
	defer debugClient.Close()
}

See the logging documentation for more details.

Development

Build

make build

Test

make test

Performance Validation

Local/persistent runtime soak/load validation is available through a dedicated soak-tagged test harness.

Smoke profile (PR gate, hard-fail thresholds, <=10m timeout target):

make test-local-load-smoke

Nightly soak profile (report-only thresholds, <=70m timeout target):

make test-local-soak-nightly

Useful environment variables:

• CHROMA_PERF_PROFILE - smoke or soak.
• CHROMA_PERF_ENFORCE - true to fail on threshold breaches, false for report-only.
• CHROMA_PERF_INCLUDE_DEFAULT_EF - include default_ef scenarios (default: true for soak, false for smoke).
• CHROMA_PERF_REPORT_DIR - output directory for perf-summary-*.json and perf-summary-*.md.
• CHROMA_PERF_ENABLE_DELETE_REINSERT - enables delete+reinsert write operations (disabled by default due to current local runtime stability issues under delete-heavy load).

See docs/docs/performance-testing.md for profile definitions, thresholds, and report schema.

Lint

make lint-fix

Local Server

Note: Docker must be installed

make server

References

• Official Chroma documentation
• Chroma Helm chart for cloud-native deployments
• Chroma Cookbook for examples and recipes