Opik by Comet

Opik by Comet is an Apache-2 open-source LLM evaluation and observability framework with a $0 Open Source plan, a $0 Free Cloud plan for up to 10 team members, 25k spans per month, 60-day retention, and a $19 per month Pro Cloud plan for up to 50 team members and 100k spans per month. Based on the supplied product metadata and current Comet pricing information verified on 2026-06-04, its core focus is the operational lifecycle of LLM applications: tracing application behavior, evaluating outputs, monitoring quality over time, and using those signals to improve prompts and model-backed workflows. This places Opik in the LLM observability and evals category rather than in a general-purpose chatbot, model provider, or prompt-only tool category.

The tool is especially relevant for engineering and machine learning teams that need more structure around how LLM applications behave in development and production. LLM systems can fail in ways that are difficult to detect with ordinary logs alone: responses may be factually weak, inconsistent, overly verbose, missing required constraints, or sensitive to small prompt and retrieval changes. Opik’s stated scope addresses that problem by combining tracing and evaluation workflows so teams can inspect what happened in an LLM call path and judge whether the resulting behavior meets expectations.

The provided metadata also identifies Opik as open source and Apache-2 licensed. That is important for organizations that want the option to inspect the implementation, self-host or extend parts of the stack, or avoid depending entirely on a closed SaaS vendor for evaluation and observability workflows. Open-source licensing can also make the tool more accessible for experimentation, internal platform teams, and organizations with stricter procurement or data governance needs. Current hosted pricing adds a concrete cloud path: Free Cloud is $0 with 10 team members, 25k monthly spans, and 60-day retention; Pro Cloud is $19 per month with up to 50 team members, 100k monthly spans, and 60-day retention; Enterprise is custom-priced with unlimited team members and custom usage plans.

Opik appears to cover several adjacent capabilities that often need to work together in mature LLM development: tracing, evals, monitoring, test suites, assertions, agent playground workflows, and prompt-related iteration. Tracing helps teams understand the sequence of steps involved in an LLM-powered request. Evaluation helps teams compare outputs against expected behavior or quality criteria. Monitoring helps track whether application quality changes over time. Prompt iteration supports changes to the instructions and templates that shape model behavior. Together, these capabilities are useful for teams moving from prototypes to production systems, where repeatability, debugging, and quality measurement matter.

The supplied scraped website content itself is hard-trimmed and mostly contains browser monitoring JavaScript rather than detailed product copy, feature pages, screenshots, deployment instructions, or integration documentation. Because of that, this directory entry avoids claiming specific SDK languages, exact UI workflows, model-provider support, hosting architecture, API authentication style, or unsupported release-note details that were not present in the provided content. The strongest factual characterization supported by the supplied material and pricing verification is that Opik by Comet is a freemium, Apache-2, open-source framework for LLM observability, tracing, evaluation, monitoring, prompt-related iteration, and improvement of LLM applications.