Opik
comet.com · Observability
Comet's open source platform for logging, evaluating and monitoring LLM apps, RAG systems and agents.
Opik is one of 10 observability tools on TrueIQ. See all observability tools or how we check facts.
Open source
// guides
Guides that cover Opik
How to Use LangSmith with LangGraph (2026)
How to use LangSmith with LangGraph: set four environment variables, read node traces and threads, then score your graph and single nodes on a dataset.
Is LangSmith API Free? Keys, Limits and Costs
Is LangSmith API free? Yes: API keys and the REST API cost nothing, and the Developer plan covers 5,000 traces a month. See key types, limits and overage costs.
Is Langfuse Free for Commercial Use? (2026)
Is Langfuse free for commercial use? Yes: the MIT core can be self hosted in paid products at no cost. See what needs a license key and when the cloud bills.
AI Agent Observability: What It Is and Top Tools
AI agent observability explained: trace tool loops, permissions and memory, the six PAI telemetry gaps, and which tools fit, from Langfuse to Datadog.
Best LLM Observability Tools in 2026, Compared
The best LLM observability tools in 2026 compared: Langfuse, LangSmith, Phoenix, Opik, Weave and more, with licenses, self hosting and who now owns what.
Langfuse vs LangSmith: Which Should You Use?
Langfuse vs LangSmith in 2026: open source license, self hosting, pricing, retention, framework fit and migration tips, so you can pick the right LLM tracer.
// related
Opik alternatives and related tools
Langfuselangfuse.comOpen source LLM engineering platform (MIT core) for tracing, prompt management, datasets and evals, free to self host. Owned by ClickHouse since January 2026.ObservabilityOpen source★ 36.6k
Laminarlaminar.shOpen source observability platform for AI agents with tracing, evaluations and browser session replays.ObservabilityOpen source★ 3.5k
Arize Phoenixarize.comFree, self hostable tracing and evaluation tool built on OpenTelemetry, source available under the Elastic License 2.0. Arize became part of Dynatrace in October 2026.ObservabilityFree★ 12k
W&B Weavewandb.aiWeights & Biases toolkit for tracing, evaluating and iterating on LLM applications.ObservabilityFreemium★ 1.1k
LangSmithlangchain.comLangChain's platform for tracing, evaluating and monitoring LLM apps and agents, framework agnostic.ObservabilityFreemium
Datadog Agent Observabilitydatadoghq.comDatadog's hosted tracing and evaluation product for LLM apps and agents (formerly LLM Observability), billed per LLM call and linked to Datadog APM and infrastructure data.ObservabilityFreemium