# LangSmith: what AI models say (September 2026)

Source: Memetik Index, https://www.memetik.ai/vendors/langsmith
Website: https://www.langchain.com

LangSmith was named in 50 of 50 AI answers across 1 category. Best position: LLM observability and evals, 100% answer share, ranked #1, named first in 16%.

## What LangSmith is

LangSmith is a platform for teams that build agents. It supports building, testing, deploying, monitoring, improving and governing agents.

Teams can build agents with or without code and choose their model. LangSmith traces agent runs, then turns those traces into datasets and evaluations. It deploys agents for long-running tasks, persistent state and secure execution. In production, it monitors quality, cost, latency, errors and tool behaviour, while controlling model calls, spend, sensitive data and human approval for sensitive actions.

(From LangSmith's own website, read 2026-09-02.)

## By category

| Category | Rank | Answer share | Named first | Models |
|---|---|---|---|---|
| LLM observability and evals (https://www.memetik.ai/index/llm-observability) | #1 of 13 | 100% | 16% | GPT-5.6 Sol, ChatGPT, GPT-5.6 Luna, Claude Opus 5, Claude, Claude Fable 5, Gemini, Gemini 3.5 Flash, Perplexity, Sonar Reasoning Pro |

## What the models said

> "Choose LangSmith if nearly everything is built with LangChain or LangGraph and you value the most direct framework integration."
> — GPT-5.6 Luna, LLM observability and evals

> "Choose LangSmith if you're deep in LangChain, or Braintrust if rigorous evals in CI/CD matter more than tracing."
> — Claude Fable 5, LLM observability and evals

> "Choose LangSmith if your app is deeply integrated into LangChain or LangGraph and you have the budget for premier agent tracing."
> — Gemini 3.5 Flash, LLM observability and evals

> "Choose LangSmith if your stack is heavily LangChain/LangGraph-based or you want fast setup for agent tracing plus evals and annotation workflows."
> — Perplexity, LLM observability and evals