opik vs langsmith-sdk
LLM tracing and evaluation platforms compared
opik and langsmith-sdk help teams trace LLM applications and support debugging, evaluation, and monitoring. opik provides a broader platform that can be self-hosted or used through Comet Cloud, while langsmith-sdk provides client libraries for sending traces to the LangSmith platform.
opik: Trace, Evaluate, and Monitor LLM Applications
Opik is Comet’s open-source platform for tracing, evaluating, and monitoring LLM applications, RAG systems, and AI agents. It combines framework integrations, datasets and experiments, prompt tools, and production dashboards, with cloud and self-hosted options.
langsmith-sdk: Trace and Evaluate LLM Applications with LangSmith
LangSmith SDKs from LangChain let Python and JavaScript/TypeScript applications trace, evaluate, and monitor language models and agents through the LangSmith platform. This repository is archived; the SDKs have moved to separate Python and JavaScript repositories.
| opik | langsmith-sdk | |
|---|---|---|
| Language | Python | Python |
| License | Apache-2.0 | MIT |
| Stars | 22.8k | 1.1k |
| Forks | 1.9k | 315 |
| Last analyzed | Oct 22, 2026 | Oct 28, 2026 |
Key differences
- opik includes a platform for traces, datasets, experiments, prompt management, and monitoring; langsmith-sdk focuses on client SDKs that send application traces to LangSmith.
- opik supports Python and TypeScript SDKs and OpenTelemetry; langsmith-sdk provides Python and JavaScript/TypeScript clients, with packages on PyPI and npm.
- opik can run locally or on a team's infrastructure, or be used through Comet Cloud; langsmith-sdk requires access to the LangSmith platform and an API key.
- opik is licensed under Apache-2.0, while langsmith-sdk is licensed under MIT.
- opik lists 22.4k stars and 1.8k forks; langsmith-sdk lists 1.1k stars and 307 forks.
Choose opik if you…
- need a platform for tracing, evaluation, and production monitoring in one workflow.
- want to self-host observability data or use Comet Cloud.
- need datasets, experiment comparisons, prompt tools, or CI/CD evaluation with PyTest.
Choose langsmith-sdk if you…
- want Python or JavaScript/TypeScript clients to send traces to LangSmith.
- need to add tracing to OpenAI clients or LangChain applications.
- already plan to use the LangSmith platform for debugging, evaluation, or monitoring.
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This comparison is generated with AI from the OSRepos analyses of both projects. Always check each project's repository and documentation before choosing.