Updated March 10, 2026
Agenta is an open-source platform for prompt engineering, evaluation, and experimentation. It provides a prompt playground, version control for prompts, A/B testing, and evaluation pipelines. Teams can iterate on prompts collaboratively, track experiments, and deploy optimized prompts to production.
LangSmith is LangChain's observability and evaluation platform for LLM applications. It provides detailed tracing of every LLM call, chain execution, and agent step—showing inputs, outputs, latency, token usage, and cost. LangSmith includes annotation queues for human feedback, dataset management for evaluation, and regression testing for prompt changes. It's the most comprehensive debugging tool for LangChain-based applications.
Core capabilities each platform advertises.
What each tool does well, and the limitations to keep in mind.
Pros
Cons
Pros
Cons
Choose Agenta if you wantChoose if you want
Choose LangSmith if you wantChoose if you want
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 500+ models through one gateway.