What are the main features of Opik?

Opik captures full traces of prompts and tool calls, includes 30+ LLM-as-a-Judge metrics, and offers a test-suite runner. It also provides real-time monitoring, alerting, and guardrails for content and PII.

How much does Opik cost?

The core platform is free to self-host. There is a free Cloud tier that does not require a credit card, and Enterprise plans are available by contacting sales.

Which frameworks and models does Opik integrate with?

Opik integrates with OpenAI, Anthropic, LangChain, LlamaIndex, LiteLLM, Haystack, and CrewAI. It provides SDKs for Python and TypeScript and supports multi-model usage.

Who is Opik designed for?

It is designed for engineering teams shipping LLM agents who want to own their telemetry pipeline. It is less suitable for teams needing only lightweight prompt logging or those standardized on other platforms.

Does Opik have an auto-fix feature?

Yes, the Ollie assistant auto-suggests and implements fixes from trace data into your repository, though this feature is noted as still maturing.

Opik

Open-source LLM observability and evaluation platform for debugging and monitoring AI agents in production.

Freemium· Free open-source self-host; free Cloud tier (no card); Enterprise contact salesEvaluationMulti-model7.3 / 10

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In short

Opik provides open-source tracing, evaluation, and monitoring for LLM applications and agents. It is best for engineering teams that want to self-host their telemetry pipeline or use a free cloud tier without credit card requirements.

Best for

Pick Opik if you're shipping LLM agents and want open-source tracing, evals, and guardrails you can self-host or run on Comet's free cloud.

Skip if

Skip it if you only need lightweight prompt logging or you've already standardized on LangSmith/Langfuse and don't want a migration.

Opik is Comet's open-source observability stack for LLM apps and agents. It captures full traces of every prompt, tool call, and intermediate step, then layers on 30+ LLM-as-a-Judge metrics (hallucination, answer relevance, task completion) plus a test-suite runner with plain-text assertions so you can unit-test agents like code. Production features include real-time monitoring, alerting, guardrails for content and PII, and a coding-agent cost dashboard that audits Claude Code and other model spend across engineering teams.

With ~19k GitHub stars, Opik is the credible open-source alternative to LangSmith and Langfuse, and Comet's pedigree in ML experiment tracking shows in the depth of the evaluation tooling. The core platform is free to self-host; a hosted Cloud tier with a no-credit-card free plan plus paid Enterprise SKUs covers teams that don't want to run infra. It's a strong fit for engineering teams already shipping agents who want to own their telemetry pipeline rather than rent it.

Integrations span the usual ecosystem: OpenAI, Anthropic, LangChain, LlamaIndex, LiteLLM, Haystack, and CrewAI, with SDKs for Python and TypeScript. The newer Ollie assistant takes things further by auto-suggesting and implementing fixes from trace data into your repo. Caveats: the dashboard breadth means a learning curve, and the auto-fix layer is still maturing.

Editor's take

Opik is one of the most credible open-source observability options for LLM apps right now, and Comet's evaluation chops make the metrics layer feel serious rather than checkbox. The free tier and self-host story remove almost every adoption excuse for a team that's already building agents.

— The AI Tool Bible editorial team

Pros

✅ Fully open-source with permissive self-hosting
✅ 30+ built-in LLM-as-a-Judge evaluation metrics
✅ Broad SDK and framework integrations (LangChain, LlamaIndex, LiteLLM, CrewAI)
✅ Production guardrails plus PII protection out of the box
✅ Free Cloud tier with no credit card required

Cons

⚠️ Feature surface area is wide; non-trivial onboarding
⚠️ Self-hosting at scale still requires real infra work
⚠️ Ollie auto-fix agent is newer and less battle-tested
⚠️ Cost dashboard is most useful if you're already on Claude Code

Use cases

llm-tracingagent-evaluationprompt-testingproduction-monitoringguardrailscost-tracking

Frequently asked

What are the main features of Opik?: Opik captures full traces of prompts and tool calls, includes 30+ LLM-as-a-Judge metrics, and offers a test-suite runner. It also provides real-time monitoring, alerting, and guardrails for content and PII.
How much does Opik cost?: The core platform is free to self-host. There is a free Cloud tier that does not require a credit card, and Enterprise plans are available by contacting sales.
Which frameworks and models does Opik integrate with?: Opik integrates with OpenAI, Anthropic, LangChain, LlamaIndex, LiteLLM, Haystack, and CrewAI. It provides SDKs for Python and TypeScript and supports multi-model usage.
Who is Opik designed for?: It is designed for engineering teams shipping LLM agents who want to own their telemetry pipeline. It is less suitable for teams needing only lightweight prompt logging or those standardized on other platforms.
Does Opik have an auto-fix feature?: Yes, the Ollie assistant auto-suggests and implements fixes from trace data into your repository, though this feature is noted as still maturing.