go-opik

A Go SDK for LLM Observability

Comet Opik | Open Source | Production Ready

What is Opik?

Opik is an open-source LLM observability platform by Comet ML

• Traces & Spans - Track LLM calls and application flow
• Datasets - Store test data for evaluation
• Experiments - Run and compare model evaluations
• Prompts - Version and manage prompt templates
• Feedback - Capture quality scores and user feedback

go-opik provides full Go SDK support for all Opik features

Quick Start

import opik "github.com/agentplexus/go-opik"

client, _ := opik.NewClient(
    opik.WithAPIKey("your-api-key"),
    opik.WithProjectName("my-project"),
)

// Create a trace
trace, _ := client.Trace(ctx, "chat-request",
    opik.WithTraceInput(map[string]any{"query": "Hello!"}),
)

// Create an LLM span
span, _ := trace.Span(ctx, "gpt-4-call",
    opik.WithSpanType(opik.SpanTypeLLM),
    opik.WithSpanModel("gpt-4"),
)

// End with output and usage
span.End(ctx, opik.WithSpanOutput(response))
trace.End(ctx)

Architecture

go-opik/
├── *.go                    # Core SDK (client, trace, span, config)
├── llmops/                 # OmniObserve provider adapter
├── evaluation/
│   ├── heuristic/          # BLEU, ROUGE, Levenshtein, etc.
│   └── llm/                # LLM-as-judge metrics
├── integrations/
│   ├── openai/             # OpenAI tracing
│   ├── anthropic/          # Anthropic tracing
│   └── omnillm/            # OmniLLM adapter
├── middleware/             # HTTP tracing middleware
└── cmd/opik/               # CLI tool

Core Features

OmniObserve Integration

Use go-opik through the unified OmniObserve abstraction:

import (
    "github.com/agentplexus/omniobserve/llmops"
    _ "github.com/agentplexus/go-opik/llmops"  // Register provider
)

// Open via OmniObserve
provider, _ := llmops.Open("opik",
    llmops.WithAPIKey("your-api-key"),
    llmops.WithProjectName("my-project"),
)

// Use unified interface
ctx, trace, _ := provider.StartTrace(ctx, "workflow")
ctx, span, _ := provider.StartSpan(ctx, "llm-call",
    llmops.WithSpanType(llmops.SpanTypeLLM),
)

Switch between Opik, Langfuse, and Phoenix without code changes.

Evaluation Metrics

Heuristic Metrics (No LLM Required)

LLM Judge Metrics

Feature Comparison

Feature	Opik (Python)	go-opik	omniobserve
Traces & Spans
Feedback Scores
Datasets
Experiments			Partial
Prompts
Distributed Tracing
Streaming
Attachments

HTTP Middleware

Automatic tracing for HTTP handlers:

import "github.com/agentplexus/go-opik/middleware"

// Wrap your handler
handler := middleware.Trace(client, myHandler,
    middleware.WithSpanName("api-request"),
    middleware.WithSpanType(opik.SpanTypeTool),
)

http.Handle("/api/", handler)

Captures:

• Request method, path, headers
• Response status and duration
• Automatic parent span detection

Installation

go get github.com/agentplexus/go-opik

Configuration

// From environment variables
// OPIK_API_KEY, OPIK_WORKSPACE, OPIK_URL
client, _ := opik.NewClient()

// Or explicit configuration
client, _ := opik.NewClient(
    opik.WithAPIKey("your-api-key"),
    opik.WithWorkspace("your-workspace"),
    opik.WithProjectName("my-project"),
)

Resources

Links

• Repository: github.com/agentplexus/go-opik
• Opik: github.com/comet-ml/opik
• OmniObserve: github.com/agentplexus/omniobserve
• Documentation: agentplexus.github.io/go-opik

License

MIT License - Open source and free to use

go-opik

Full-featured Go SDK for Opik LLM Observability

go get github.com/agentplexus/go-opik

• Traces, spans, feedback scores
• Datasets, experiments, prompts
• Evaluation metrics (heuristic + LLM)
• OmniObserve integration
• Production ready