Opik

What is Opik?

Opik is an LLM observability and evaluation platform from Comet that logs every step an AI agent takes, including retrieval, tool calls and model responses. Teams use the traces to debug failures, then score outputs with more than 30 built-in LLM-as-judge and heuristic metrics, test suites with plain-text assertions, and datasets for regression and A/B experiments. An Agent Playground runs a whole agent with different prompts and parameters, a Prompt Optimizer offers six algorithms, and the Ollie assistant reads traces and proposes code fixes. In production Opik evaluates traces, alerts on failures, applies guardrails and tracks token usage and cost. It integrates with over 40 frameworks and model providers and accepts OpenTelemetry. The full feature set is open source and can be self-hosted, and Comet also runs a hosted version. Pricing: Open Source and Free Cloud are $0, Pro Cloud is $19 per month, and Enterprise is custom.

Use cases

• Trace every step of an AI agent
• Evaluate LLM outputs with judge metrics
• Run regression tests on agent changes
• Monitor production traces and alert on failures
• Track token usage and model cost
• Optimize prompts across a dataset
• Annotate traces with expert reviewers

Who it's for

• AI engineers
• ML teams
• Enterprise AI teams
• Subject matter reviewers

Why use Opik

• See where an agent fails because each retrieval, tool call and model response is logged in one trace.
• Define pass or fail rules in plain text with Test Suites instead of building metrics and datasets for every check.
• Start free: the open-source version has the full feature set and the Free Cloud plan needs no credit card.
• Keep data on your own infrastructure by self-hosting the same codebase that powers the hosted versions.
• Catch production problems early through real-time trace evaluation, alerts and guardrails.

Opik features

• Agent tracing with execution graphs and multi-turn sessions
• Test Suites with item-level and suite-level assertions
• 30+ built-in evaluation metrics plus custom metrics
• Evaluation datasets and experiments dashboard
• Annotation queues and custom feedback schemas
• Agent Playground to run whole agents end to end
• Prompt Optimizer with six algorithms
• Ollie assistant that analyzes traces and proposes fixes
• Production monitoring, alerts and guardrails
• Token and cost tracking
• OpenTelemetry support
• Cost Intelligence for coding agent usage

Opik integrations

• LangChain
• LangGraph
• OpenAI
• Google ADK
• CrewAI
• Ragas
• Hugging Face Datasets
• Gretel
• OpenTelemetry
• Claude Code
• Codex

How to get started with Opik

1. Create a free Comet account or run Opik yourself from GitHub with Docker or Kubernetes.
2. Add the SDK or an integration, or send OpenTelemetry data, so each agent run is logged as a trace.
3. Build datasets and test suites, then score traces with built-in or custom metrics.
4. Compare prompts and configurations in the Experiments dashboard or Agent Playground, and optimize prompts.
5. Monitor production traces, review alerts, and let Ollie suggest fixes you can add back as test cases.

Opik limitations

• Free Cloud allows 25k spans per month with 60-day data retention
• Pro Cloud allows 100k spans per month unless you customize limits
• Single sign-on, service accounts and flexible deployments are Enterprise features
• Self-hosting runs on your own Docker or Kubernetes setup

Opik pricing

Yes, Opik has a free plan. Paid plans start at $19 per month, according to the official pricing page on 24 Oct 2026.

Opik plans

• Open Source

  $0

  free, self-hosted

  • Full observability and agent testing feature set
  • Same codebase as hosted versions
  • Agent tracing and analysis
  • Test Suites and assertions
  • Agent Playground

• Free Cloud

  $0

  free plan

  • Up to 10 team members
  • 25k spans per month
  • 60-day data retention
  • Ollie coding harness trial

• Pro Cloud

  $19

  per month

  • Up to 50 team members
  • 100k spans per month
  • Customizable monthly span limits
  • Customizable data retention

• Enterprise

  Custom

  • Unlimited team members
  • Custom usage plans
  • Single sign-on
  • Dedicated support and SLAs
  • Flexible deployments

Plans as listed on the official pricing page on 24 Oct 2026. Prices can change and may vary by country or exclude tax. Check the official pricing page.

Opik alternatives

The main Opik alternatives listed on Debuly are Langfuse, Arize Phoenix, Braintrust, Galileo, Arize AX and OpenLIT. The table compares pricing and platforms; order is A–Z.

1. 

   Arize AX

   Observability and evaluation platform for AI agents and LLM apps, with tracing, issue detection and experiments on a free plan.

   Developer platformsAutomation and agentsCoding
   FreemiumVisit Arize AX (official site)
2. 

   Arize Phoenix

   Open-source tool for tracing, evaluating and experimenting on LLM apps and agents, free to self-host or run locally.

   Developer platformsAutomation and agents
   Open sourceVisit Arize Phoenix (official site)
3. 

   Braintrust

   AI observability and evaluation platform for tracing LLM apps and agents, scoring outputs and catching regressions before release.

   Developer platformsCoding
   FreemiumVisit Braintrust (official site)
4. 

   Galileo

   AI observability and eval platform that tunes evals to your data and turns them into guardrails for LLM apps and agents.

   Developer platformsAutomation and agents
   FreemiumVisit Galileo (official site)
5. 

   Langfuse

   Open-source LLM observability and evaluation platform for tracing agents, managing prompts and scoring outputs.

   Developer platformsAutomation and agentsCoding
   FreemiumVisit Langfuse (official site)
6. 

   OpenLIT

   Open-source, OpenTelemetry-native platform for tracing, evaluating and guarding AI agents, with cost and GPU monitoring

   Developer platformsCodingAutomation and agents
   Open sourceVisit OpenLIT (official site)

Opik FAQ

Sources & verification

Facts on this page come from the official sources below, each with the date we read it. Written by Debuly; the vendor did not review this page.

Image credits

• Logo: from comet.com · fetched 24 Oct 2026 · Vendor trademark, used only to identify the product; removed on request
• Cover: none collected yet, so a generated tile is shown.

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