LangChain

Full Trace Visibility

LangSmith provides native tracing for popular agent frameworks and OpenTelemetry SDKs for Python, TypeScript, Go, and Java. Each run is broken into a structured timeline of steps, showing exactly what happened, in what order, and why. Message threading supports multi-turn chat interactions, and analytics offer AI-driven insights to uncover patterns across traces.

Understand exactly what your agent is doing at every step, making debugging and optimization faster.

Iterative Improvement with Real-World Data

LangSmith captures production traces and turns them into test cases. You can score agents with a mix of human review and automated evals, including reusable LLM-as-judge and multi-turn evals. Human feedback annotations and online/offline scoring help calibrate evals, so each iteration makes your agent measurably better.

Continuously improve agent performance based on actual usage and feedback.

Scalable Agent Server

LangSmith Deployment provides a purpose-built server for long-running agents, with memory, conversational threads, and durable checkpointing out of the box. It supports human-in-the-loop interactions, input concurrency, background agents, and type-safe streaming of messages, UI components, and custom events. The runtime is fault-tolerant and scales to handle agent swarms, with native protocol support for A2A and MCP.

Ship and scale production agents reliably, even with complex async workflows.

Autonomous Agents for Everyday Tasks

LangSmith Fleet lets you describe a task in plain language, and it takes action across your daily tools. Turn any question or task into a recurring agent that improves with feedback and acts autonomously. It includes prebuilt templates, remote MCP server tool integration, API triggers, and LangChain model support. Enterprise security and admin controls are built in.

Automate routine tasks like research, follow-ups, and status checks across your organization.

Autonomous Issue Detection and Fixes

LangSmith Engine clusters production failures into prioritized issues, finds the root cause in your traces and code, and proposes fixes for your review. It monitors traces autonomously, clusters agent behavior into issues, diagnoses code failures, and recommends fixes to prompts and code. It also creates datasets for human review and offline/online evals to prevent repeated failures.

Surface and diagnose undetected issues autonomously, improving agents faster.

Flexible Frameworks for Any Model Provider

LangChain offers open source frameworks including deepagents for highly autonomous, long-running agents, langchain for quick starts with any model provider, and langgraph for production agents requiring low-level control. These frameworks are used by the largest builder community in AI, with 200M+ monthly open source downloads.

Build agents fast with the right level of control, from batteries-included to low-level.

• Large and active communityLangChain reports 200M+ monthly open source downloads, 7K+ active LangSmith customers, and 5 of the Fortune 10 as LangSmith customers.
• Comprehensive agent development platformLangSmith offers observability, evaluation, deployment, fleet management, sandboxes, and an LLM gateway, covering the full agent lifecycle.
• Flexible pricing tiersPricing includes a free Developer tier, a Plus tier at $39/seat/month, and Enterprise with custom pricing, plus startup credits up to $10,000.
• Multiple hosting optionsLangSmith can be hosted in the cloud, hybrid, or self-hosted, with enterprise options for custom SSO, ABAC, RBAC, and support SLAs.

• Pricing is usage-basedBeyond included base traces, costs are pay-as-you-go with LCUs (LangChain Compute Units) at $1.50/LCU and LSUs (LangChain Storage Units) at $1.00/LSU. Actual consumption varies.
• Feature availability varies by planDeployment, Engine, Fleet, Sandboxes, and LLM Gateway have different inclusions and limits per plan. For example, Deployment is N/A on the Developer plan, and Engine is only available on Plus and Enterprise.
• Enterprise plan requires contacting salesCustom pricing, self-hosted/hybrid options, and advanced security features are only available through the Enterprise plan, with no public pricing listed.
• Usage calculator is an estimateThe LangSmith Usage Calculator provides an estimate only; actual LCU/LSU consumption varies with the work agents perform, and the example monthly total of $49 is illustrative.

Debug and Understand Agent Behavior

LangSmith's observability features break each agent run into a structured timeline of steps, showing exactly what happened, in what order, and why. This helps teams pinpoint where long context, branching logic, or tool interactions went wrong, making complex agents easier to debug and understand.

Improve Agents with Real-World Usage

Teams can capture production traces, turn them into test cases, and score agents using a mix of human review and automated evals. With reusable LLM-as-judge and multi-turn evals, plus human feedback annotations, each iteration makes your agent measurably better.

Ship and Scale Agents in Production

LangSmith Deployment provides a purpose-built agent server with memory, conversational threads, and durable checkpointing out of the box. It supports human-in-the-loop interactions, input concurrency, background agents, and a scalable distributed runtime to handle agent swarms, with native protocol support for A2A and MCP.

Automate Routine Tasks with Fleet Agents

LangSmith Fleet lets users describe tasks in plain language and turn them into recurring agents that act across daily tools. These agents improve with feedback, include enterprise security and admin controls, and can be extended with any MCP server or first-party integrations, with integrated LangSmith tracing.

Define the exact AI Automation & Workflow Tools workflow LangChain should support.

Compare it with closely related AI tools in the same category before committing.

Set review rules for accuracy, privacy, brand voice, compliance, and final approval.

Connect useful outputs to the wider stack instead of leaving them inside the AI tool.