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LangChainAI Observability

LangSmith

LangChain's platform for teams tracing and evaluating LLM applications and agents. It also deploys agents on LangChain's cloud or your infrastructure, with or without the LangChain frameworks.

The 30-Second Take

Pick LangSmith if your agents already serve users and you want traces, experiments and hosting from one vendor.

Each change gets scored against datasets built from your own production failures. monday.com runs an LLM judge in CI before each deploy.

Best fit
Teams running LLM agents in production that need traces to debug failures and evals to gate changes, as monday.com does in CI.
Main constraint
Extra traces are metered, base retention lasts 14 days, and self-hosting requires Enterprise.
First move
Trace one production agent on Plus, leave base retention on, and set a monthly usage limit.

Why

Watch retention and hosting: base retention lasts 14 days, extra traces are metered, and self-hosting needs an Enterprise contract. Teams that left in 2026 chose Langfuse to keep trace data inside their own boundary.

Practitioner sentiment, all practitioners+17 Mixed

92 practitioners, 125 sources reviewed, Updated Nov 1, 2026How this is measured

Read the GILD Review
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Operating stack
AI Application Platform

Comparisons

How does LangSmith compare with the alternatives?

  1. LangSmith vs Langfuse

    • AI Observability

    Cue Labs and one developer's personal platform retired LangSmith for Langfuse in October 2026 to keep trace data in their own boundary, while monday.com and SonderMind run release evals in LangSmith. Langfuse's MIT core self-hosts free; LangSmith self-hosts only on Enterprise and bills per seat and per trace.

  2. LangSmith vs Arize

    • AI Observability

    In Parlance Labs' July 2026 test on 100 hand-labeled traces, LangSmith Engine surfaced too few issues to score, LangSmith's chat agent caught 79.5% of failures and 91.0% of Arize Alyx's flags were valid. Pick Arize AX when the same team also monitors classic ML models; pick LangSmith when LangChain should host the agents.

  3. LangSmith vs Braintrust

    • AI Observability

    Pick LangSmith, priced per seat and per trace, when LangSmith Deployment should host the agents too. Pick Braintrust when many people need access: it charges a flat platform fee with unlimited users, plus gigabytes ingested and scores recorded.

Operator Insights

What are teams learning from building on LangSmith and running it in production?

See all 9 operator accounts

Buying and deployment

What a team building on it should verify before production traffic grows.

Sourced from LangChain documentation

How you buy it

US$39

Per seat per month for Plus, with 10,000 base traces. Developer is free for one seat.

Source 1, langchain.com, Plans and pricing: Plans and pricing

Details

Developer costs US$0 for 1 seat and 5,000 monthly base traces. Plus costs US$39 per seat per month, with 10,000 monthly base traces and 1 free Small Serverless deployment. Enterprise uses custom annual invoices. Self-serve seats bill monthly, with trace usage billed monthly in arrears.

Cost drivers

US$5 per 1,000

Base traces past the allowance, kept 14 days. Evaluators upgrade traces by default.

Source 1, langchain.com, Plans and pricing: Plans and pricingSource 2, LangChain, Usage and billing: Usage and billing

Details

Beyond the included volume, a base trace with 14-day retention costs 0.005 LSU, or US$5 per 1,000. Extended retention lasts 180 days and adds 0.0025 LSU per trace. 1 LSU equals US$1. Online evaluators and automation rules upgrade traces by default. Deployment, Engine, Fleet, and Sandboxes also bill in LSUs.

Where it runs

US, EU, APAC

LangChain Cloud regions on GCP, plus AWS US. Enterprise can self-host on Kubernetes.

Source 3, LangChain, Cloud regions: Cloud regionsSource 4, LangChain, Self-hosted LangSmith: Self-hosted LangSmithSource 5, LangChain, LangSmith Deployment: LangSmith DeploymentSource 6, LangChain, Trace with OpenTelemetry: Trace with OpenTelemetry

Details

LangChain Cloud runs in GCP US, EU, and APAC regions and an AWS US region. Enterprise adds self-hosting on Kubernetes. Agent workloads also support hybrid and BYOC. Tracing connects through Python and TypeScript SDKs, LangChain integrations, or OpenTelemetry.

What to verify

14 days

Base trace data is deleted then, but some metadata is kept indefinitely.

Source 1, langchain.com, Plans and pricing: Plans and pricingSource 2, LangChain, Usage and billing: Usage and billingSource 7, LangChain, Prevent logging of sensitive data in traces: Prevent logging of sensitive data in traces

Details

LangChain says it does not train on traces. It deletes base trace data after 14 days but keeps some metadata indefinitely for analytics and billing. Dataset examples never expire. The SDK can hide or mask inputs and outputs before export.

Signals

What is the current evidence saying about LangSmith?

A current read of what teams, technical leaders, and individual developers report publicly about LangSmith, with each finding linked to its sources.

Whose sources count

Practitioner sentiment, all practitioners

+17 Mixed net

of 96 sources that take a side, each author counted once.

How this figure is made

Teams and leaders have 19 accounts; GILD prints their sentiment from 20.

Current sentiment

Positive, mixed and negative sources

The score counts them as 35 positive, 38 mixed and 19 negative votes, one per author.

The read is mixed, and it depends on who is talking: teams and leaders lean positive, individual developers are mixed. Trace-level debugging draws the most praise, from 28 of 35 sources. The UI and SDK draw the most concerns, then price in 12, and 16 of the 25 that compared platforms chose another tool.

Run a pilot on one production app to measure which failures it surfaces and how long tracing them takes.

Evidence field. All 125 sources, one mark each.

Arrange by

Each mark is one source: positive, mixed, negative, no opinion stated, or documentation (not counted).

By sentiment, All practitioners. Every source GILD read, grouped as the field draws it.
GroupSourcesPositiveMixedNegativeNo opinion stated and not counted in the scoreDocumentation, checked and not counted
Positive35350000
Mixed41041000
Negative20002000
Not counted14000140
Documentation15000015
Every source GILD read, by the quarter it was published, as the field's time axis counts it. Documentation is dated by the day it was checked.
QuarterSources
Q1 20255
Q2 20257
Q3 202512
Q4 202512
Q1 20268
Q2 202623
Q3 202636
Q4 20267
Documentation, checked15

By sentiment

15 documentation pages check facts and are not counted.

Hover a mark for a quick look, click it or press Enter to open its source.Tap a mark to open its source, then step to its neighbors with Previous and Next.

What practitioners praise

Top praise of 4. Each mark is a source on it; filled marks praise it.

  1. Trace-Level Debugging28 of 35 sources on it praise it

Most common concerns

Top concern of 5. Each mark is a source on it; filled marks raise it.

  1. UI & SDK Reliability23 of 25 sources on it raise it as a concern
All 125 sources behind these findings
  1. How We Gave AI Agents the Keys to Production and Still Sleep at NightPablo Sebastian Martinez, Production Engineering team, monday.com (self-described: monday.com Infra agents platform, where agents resolve infrastructure tickets and approve production pull requests), Company engineering blog, engineering.monday.com, published Oct 26, 2026
  2. Add configurable LangSmith tags to Compass telemetryDan Haggerty, agents engineer at NVIDIA (self-described: NVIDIA NeMo Compass, whose development traces reach LangSmith over OpenTelemetry), GitHub pull request, published Oct 22, 2026
  3. Usage and billingLangChain (Official), Product documentation, checked Oct 12, 2026
  4. Manage billingLangChain (Official), Product documentation, checked Oct 12, 2026
  5. Data purging for complianceLangChain (Official), Product documentation, checked Oct 12, 2026
  6. Tracing quickstartLangChain (Official), Product documentation, checked Oct 12, 2026
  7. Trace with OpenTelemetryLangChain (Official), Product documentation, checked Oct 12, 2026
  8. Evaluation conceptsLangChain (Official), Product documentation, checked Oct 12, 2026
  9. Annotation queuesLangChain (Official), Product documentation, checked Oct 12, 2026
  10. Prompt & Context HubLangChain (Official), Product documentation, checked Oct 12, 2026
  11. Cost trackingLangChain (Official), Product documentation, checked Oct 12, 2026
  12. AlertsLangChain (Official), Product documentation, checked Oct 12, 2026
  13. Prevent logging of sensitive dataLangChain (Official), Product documentation, checked Oct 12, 2026
  14. Cloud (SaaS)LangChain (Official), Product documentation, checked Oct 12, 2026
  15. Self-hosted LangSmithLangChain (Official), Product documentation, checked Oct 12, 2026
  16. LangSmith DeploymentLangChain (Official), Product documentation, checked Oct 12, 2026
  17. Trace Claude Code applicationsLangChain (Official), Product documentation, checked Oct 12, 2026
  18. refactor(observability): drop LangSmith, Langfuse as the single LLMOps backboneAndre Kanmegne, on andrelair-platform, his personal homelab project (self-described: RAG and contract-analysis services on a self-hosted Kubernetes cluster with EU data residency and outbound traffic denied by default), GitHub pull request, published Oct 11, 2026
  19. Comment on: How will LangChain continue making money?Hackerjurassicpark, Reddit user, self-described, Reddit comment, r/LangChain, published Oct 9, 2026
  20. Consolidate LLM observability on Langfuse; retire LangSmithobarton, contributor to Cue Labs' cue-app repository (self-described: Cue Labs' customer-support agents for Instagram direct messages, chat and SMS, built on LangChain and LangGraph), GitHub pull request, published Oct 9, 2026
  21. Comment on: When you change a RAG pipeline, how do you know which queries actually regressed?Unlucky_Emu6094, Reddit user (self-described: RAG pipeline changes), Reddit comment, r/LangChain, published Oct 8, 2026
  22. epic: digitrace rename + self-hosted Langfuse on Cloudflare (cut LangSmith)Chris (chrizefan), Owner/approver of tooling decisions at digithings.ai (self-described: digithings.ai LangGraph workloads (house-run, OpenWiki, digiquant-baseline)), GitHub issue, published Oct 1, 2026
  23. From Supervisor to Deep Agents: Re-Architecting a Production GTM Assistant Without Breaking TrustAniruddha Laud and Anshul Pahwa, AI engineers, Apollo.io (self-described: Apollo.io AI assistant for go-to-market teams, in general availability), Conference talk, Interrupt NYC 2026 (LangChain YouTube channel), published Sep 29, 2026
  24. From One-Off Agents to an Agent FactoryDotan Limon and Jordan Kamm, Chief Product and Technology Officer, Weber Shandwick; agent engineer, Focused (self-described: Weber Shandwick client agents built with Focused, one reusable architecture per brand), Conference talk, Interrupt NYC 2026 (LangChain YouTube channel), published Sep 29, 2026
  25. The Safety Net Behind the Conversation: LangSmith for Mental Health AIMarissa Saunders, Senior Director of Engineering, Spring Health (self-described: Spring Health, member-facing AI agent for mental health care), Conference talk, Interrupt NYC 2026 (LangChain YouTube channel), published Sep 29, 2026
  26. Remove the paid-LangSmith wiring now that the subscription is cancelledTyler Norlund (tnorlund), Developer, maintainer of a personal portfolio repo (self-described: Personal portfolio with LangGraph receipt and QA agents on AWS), GitHub issue, published Sep 28, 2026
  27. Bug: First turn intermittently missing from LangSmith Trajectory viewTejasri Teyam, developer filing a GitHub issue (self-described: Multi-turn LangGraph application traced to LangSmith Cloud), GitHub issue, published Sep 25, 2026
  28. Comment on: We built a LangGraph integration for our agent runtimeMysteriousPlan6, Reddit user (self-described: Multi-agent LangGraph workflows), Reddit comment, r/LangChain, published Sep 23, 2026
  29. Issue: evaluate_comparative with randomize_order records concurrent comparators' scores against the wrong runsMaverick (mavericksea-ai), builder of Driftproof, an evaluation reliability product (self-described: Pairwise LLM-judge experiments with two comparative evaluators and randomized order), GitHub issue, published Sep 23, 2026
  30. Move the pipeline onto LangGraph, LangChain and LangSmith; remove LogfirePatrick Porche Jr, product engineer building AI tools with clinicians and operations teams (self-described: Medical-necessity review pipeline on Anthropic and Google models, with a patient-data boundary), GitHub pull request, published Sep 21, 2026
  31. claude_agent_sdk integration: receive_messages() is not instrumented, traces silently lost for the full-stream consumption pathJamesDun, developer filing a GitHub issue (self-described: Interactive multi-turn sessions on the Claude Agent SDK, traced through LangSmith's integration), GitHub issue, published Sep 20, 2026
  32. AI Evals: Everything You Need to KnowHamel Husain, AI evals consultant and course instructor (co-written with Shreya Shankar) (self-described: Advising client teams on eval tooling and vendor selection), Personal blog post, hamel.dev, published Sep 18, 2026
  33. Why I think Vercel EVE Web interface is so much better than Langsmith for development.Daniel Payne, Developer (self-described long-time programmer) (self-described: Solo app that values building-material photos with a Vercel Eve agent; previously used LangGraph and LangSmith), Medium article, published Sep 16, 2026
  34. I open-sourced a multi-bot runtime that uses LangMem and LangSmithregnull, Reddit user (self-described: Solo, open-source self-hosted multi-bot platform), Reddit post, r/LangChain, published Sep 14, 2026
  35. Comment on: What is the best AI observability tool in 2026?Capable-Purpose9911, Reddit user (self-described: Small app on a 4 to 4.5 GB RAM host), Reddit comment, r/LangChain, published Sep 9, 2026
  36. Building a Robust Harness for agent in production: Feed agent case-studyKamie Shami-Schnitzer, feedAgent builder, monday.com (self-described: monday.com feedAgent, a deep agent that curates a personal activity feed for each workspace member), Company engineering blog, engineering.monday.com, published Sep 9, 2026
  37. Import time: langchain_core.runnables eagerly imports the langsmith SDK via tracer modulesBerniebiloxi, Developer (issue author) (self-described: CLIs, serverless entry points and test collection importing langchain_core), GitHub issue, published Sep 6, 2026
  38. Cut local stack from ~47 containers to 14; Langfuse → LangSmithTitus Lim (tituslhy), Data scientist (GitHub profile) (self-described: Agent template repo (AG-UI / A2UI / A2A) on LangGraph), GitHub pull request, published Sep 3, 2026
  39. feat: replace LangSmith with self-hosted Langfusepallasaisrujan28, developer of an enterprise agent framework (self-described: Agent framework deployed on Amazon EKS in eu-west-2), GitHub pull request, published Aug 25, 2026
  40. Keep Every LangSmith Trace Without the 10 Retention BillAviad Rozenhek, Developer and maintainer of the open-source langsmith-cli (self-described: Operates LangSmith for live debugging of production AI systems; built an S3/Parquet archive workflow for traces), dev.to article, published Aug 21, 2026
  41. Comment on: How are you actually debugging complex LangChain agents?True-Homework6226, Reddit user (self-described: Multi-step LangChain agents), Reddit comment, r/LangChain, published Aug 10, 2026
  42. feat: self-hosted OTel observability (Phoenix/Langfuse) for multi-agent tracing - not LangSmithAndrew Kaszubski (akaszubski), Developer, maintainer of the autonomous-dev Claude Code plugin (self-described: Local-first multi-agent coding harness on Claude Code / claude-agent-sdk), GitHub issue, published Aug 6, 2026
  43. feat: migrate observability from LangSmith to Langfuse Cloud (v4 SDK)icekarim, developer of the momo personal assistant (self-described: Solo assistant on Anthropic models deployed on Cloud Run, with scheduled briefing jobs), GitHub pull request, published Aug 5, 2026
  44. Anyone here using Lang graph with o11y that is not Langsmith?type-hinter, Reddit user (self-described: Solo, toy and experimental LangGraph projects), Reddit post, r/LangChain, published Jul 30, 2026
  45. Amazon Bedrock Claude Sonnet 5 US geo profile is priced at the global rateGabriel Gouvêa, software engineer at movedot (self-described: Hosted LangSmith cost tracking for Claude Sonnet 5 runs through Amazon Bedrock's US cross-region profile), GitHub issue, published Jul 28, 2026
  46. Comment on: My 10-Node Agentic RAG Architecture: Combining LangGraph, Cohere, Pinecone & MCP for Dense Legal Parsingambujsystems, Reddit user (self-described: Solo, 10-node LangGraph RAG pipeline on free infrastructure), Reddit comment, r/LangChain, published Jul 26, 2026
  47. Evals Driven-Development: Engineering a Mental Health AI Coach Ethically & SafelyAkele Reed and Dave Revere, Principal AI Engineer and Staff AI Engineer, SonderMind (Sonder, SonderMind's AI mental health coach, with guardrail evals written from clinician annotations), Conference talk with transcript, AI Engineer World's Fair 2026, published Jul 25, 2026
  48. Comment on: We tested LangGraph against 8 other frameworks in 2026dataplayer, Reddit user, self-described, Reddit comment, r/LangChain, published Jul 24, 2026
  49. How Coinbase Builds Developer Support Agents | Interrupt 26Evan Kormos, Engineering manager, Coinbase (Coinbase developer support team, Discord and Slack support agents), Conference talk, Interrupt 26 (LangChain YouTube channel), published Jul 20, 2026
  50. Comment on: Doubtautomation_experto, Reddit user (self-described: Agents built on document extraction), Reddit comment, r/LangChain, published Jul 19, 2026
  51. Build Evals That Actually MatterNick Ung and Akshay Sharma, data science manager and machine learning engineer, Lyft (self-described: Lyft AI Assist customer-support agents, with LLM judges checked against about 100 hand-labeled pass and fail examples), Conference talk with transcript, AI Engineer World's Fair 2026, published Jul 19, 2026
  52. Comment on: Anyone else feel like LangChain is amazing for a demo, but a nightmare for production?GeneralMongoose5979, Reddit user (self-described: LangGraph agents in production at low volume), Reddit comment, r/LangChain, published Jul 17, 2026
  53. Replace custom tracing with LangSmith observabilityJuan Cruz Boullosa Gutierrez, contributor to a LangGraph Discord bot (self-described: LangGraph Discord bot with direct-message and crisis paths, traced with inputs and outputs hidden), GitHub pull request, published Jul 16, 2026
  54. Building ToyotaGPT: 50+ Production Agents, One Config File, Zero Architecture ReviewsRavi Chandu Ummadisetti and Kordel France, Head of agent AI and product research, and head of AI engineering, Toyota (self-described: ToyotaGPT, Toyota's enterprise agent platform with 50+ agents in production), Conference talk, Interrupt 26 (LangChain YouTube channel), published Jul 15, 2026
  55. How to Evaluate Agents Locally with Arize PhoenixFolarin Akinloye, AI engineer in London (self-described: Agent evaluation when traces cannot leave the team's own infrastructure), Personal blog post, folarin.dev, published Jul 12, 2026
  56. Do Automated Evals Work?Antaripa Saha and Hamel Husain, AI evals consultants, Parlance Labs (self-described: 100 production traces from Nurture Boss's apartment-leasing agent, hand-labeled with a domain expert into 39 failures, then given to Braintrust Loop, Arize Alyx, LangSmith and three coding agents), Independent evaluation, Parlance Labs blog, published Jul 11, 2026
  57. My AI Agents Were Working, but I Had No VisibilityHugo Santana, Builder of Applied, author of The Applied Report (self-described: Solo; custom multi-agent system (Applied) sending run summaries to LangSmith), Newsletter, Agent-led Growth (Substack), published Jul 7, 2026
  58. langsmith + testmu running together. prod regressions still slipping. what’s the missing layer?FeeVirtual, Reddit user (self-described: Production agents traced in LangSmith, with an agent-to-agent adversarial eval tool and custom rubrics in CI), Reddit post, r/AI_Agents, published Jul 2, 2026
  59. Comment on: 6 things I learned deploying AI agents for B2B clients (the hard way)Previous_Net_1154, Reddit user (self-described: B2B client agents in production), Reddit comment, r/LangChain, published Jun 30, 2026
  60. Migrate observability from Langfuse to LangSmithMarkAZhang, developer of a GAIA benchmark research agent (self-described: LangGraph research agent scored on the GAIA benchmark with five evaluators), GitHub pull request, published Jun 30, 2026
  61. How LATAM Airlines Built Intelligent Agents in Aviation | Interrupt 2026Nico Venegas and Claudio Urbina Lara, LATAM Airlines AI team (self-described: LATAM Concierge, a LangGraph travel agent with 4,000 daily users), Conference talk, Interrupt 26 (LangChain YouTube channel), published Jun 30, 2026
  62. Make Legal Write Your Evals: Building Jade, Chime's Financial Copilot | Interrupt 26Philipp Comans, Software engineer, Chime (self-described: Jade, Chime's AI financial copilot), Conference talk, Interrupt 26 (LangChain YouTube channel), published Jun 22, 2026
  63. Are there any tools out there automatically suggesting possible agent improvements?poushkar, Reddit user, self-described, Reddit post, r/LLMDevs, published Jun 20, 2026
  64. Evaluating Agents with LangSmith: A Complete GuideFolarin Akinloye, AI engineer in London (self-described: Agents built with LangChain and LangGraph, traced from day one and tested against datasets before each change), Personal blog post, folarin.dev, published Jun 19, 2026
  65. How Lyft Builds Evals That Actually Matter in Production | Interrupt 26Nick Ung, Leads data science and ML for safety and customer care at Lyft (self-described: Lyft AI Assist customer-care agents (LangChain, LangGraph, LangSmith), about 270,000 AI interactions per month), Conference talk, YouTube (LangChain channel, Interrupt 26), published Jun 15, 2026
  66. Comment on: Apache Burr: Build reliable AI agents and applicationsfxwin, Hacker News commenter, self-described, Hacker News comment, published Jun 10, 2026
  67. Observing And Testing CX Agents | Interrupt 26Carlos Pereira, Cisco Customer Experience team (as described in the video) (self-described: Cisco CX support agents, about 16 million interactions a year; a triage agent pulls LangSmith traces via MCP and opens Jira issues), Conference talk, YouTube (LangChain channel, Interrupt 26), published Jun 10, 2026
  68. Building an AI Billing Assistant: Integrating LangChain ReAct Agents with Spring Boot MicroservicesDaniel Cordeiro, developer (self-described: Telecom billing support agent: LangChain ReAct agent in FastAPI calling Spring Boot services), dev.to article, published Jun 8, 2026
  69. The Etsy Gifting Assistant: From Prototype to Production | Interrupt 26Derrick Kondo, Engineer, GenAI Enablement team, Etsy (self-described: Etsy gifting assistant, about three senior engineers and one designer), Conference talk, Interrupt 26 (LangChain YouTube channel), published Jun 8, 2026
  70. LangSmith for local tracingConsistent_Wash_276, Reddit user (self-described: Solo, first LangGraph project), Reddit post, r/LangChain, published Jun 7, 2026
  71. Spent 3 months evaluating Galileo, Arize, Langfuse and LangSmith for production LLM monitoring. Notes for anyone doing the same.Total_Listen_4289, Reddit user (self-described: Small team shipping agents), Reddit post, r/LLMDevs, published May 30, 2026
  72. Testing LangChain agents beyond LangSmith eval scripts: what's actually catching prod issues?itsmeAki, Reddit user (self-described: Sales-qualification chat agent in production), Reddit post, r/LangChain, published May 30, 2026
  73. Trace a Quarkus LangChain4j App in LangSmithMarkus Eisele, Java developer and newsletter author (self-described: Example Quarkus LangChain4j support assistant on Ollama exporting OpenTelemetry traces to LangSmith), Newsletter, The Main Thread (Substack), published May 30, 2026
  74. feat: self-hosted Langfuse alongside LangSmithAryan Randeriya, founder and CEO of Experience Inc., which builds GAIA (self-described: GAIA, an open-source personal AI assistant whose agents, sub-agents and MCP tools are traced in LangSmith), GitHub pull request, published May 28, 2026
  75. I ran langfuse, langsmith and helicone in prod for a month and only one of them stuckrafio77, Reddit user (self-described: Team running agents in production, mostly outside LangChain), Reddit post, r/LLMDevs, published May 20, 2026
  76. Are there any genuinely good open-source alternatives to LangSmith right now?Bladerunner_7_, Reddit user, self-described, Reddit post, r/LangChain, published May 15, 2026
  77. How to integrate Langchain and Trace with OpenTelemetry without using LangSmithPager_dot, Reddit user, self-described, Reddit post, r/LangChain, published May 11, 2026
  78. Show HN: I built an open-source, local-first alternative to LangSmithshivnathtathe, Hacker News poster; author of opensmith (self-described: Solo, Python LLM apps), Hacker News post (Show HN), published May 8, 2026
  79. How I Built an Autonomous PR Agent with SerpApi, LangGraph, and LangSmithStefano Casafranca, Independent developer (maker of the open-source Build_Script) (self-described: Solo; autonomous Reddit-marketing agent on LangGraph and GitHub Actions, two weeks in production), dev.to article, published Apr 30, 2026
  80. Extreme lagging on Langsmith PlaygroundErzErzHerzog, Developer (issue author) (self-described: Debriefing live agent runs in the Playground), GitHub issue, published Apr 15, 2026
  81. Tracing Claude Code with LangSmith: Full Observability for Your AI Coding AgentBalachander Keelapudi, Balachander's Substack (self-described: Tracing Claude Code sessions, tool calls and subagents with the official LangSmith plugin), Newsletter, Balachander's Substack, published Apr 4, 2026
  82. Setting up Evaluations for LLMsAishwarya Srinivasan, Aishwarya Srinivasan (Substack) (self-described: Hands-on eval pipeline: reference datasets, heuristic checks and LLM-as-judge (Gemini grading Claude) orchestrated in LangSmith), Newsletter, Aishwarya Srinivasan (Substack), published Mar 31, 2026
  83. Feature Request: Custom Input Rendering for Annotation QueuesjdudekBC, Developer (issue author) (self-described: Team building golden evaluation datasets with annotators), GitHub issue, published Mar 18, 2026
  84. I Tried to Build an Alexa with Real Memory: Here's What I Learned After 3 Months of Failurevivek, Independent developer (self-described: Solo personal-assistant project with LangGraph, Groq, Pinecone, Postgres and Redis over three months), dev.to article, published Mar 5, 2026
  85. Comment on: Launch HN: Cekura (YC F24) - Testing and monitoring for voice and chat AI agentsMickeyShmueli, Hacker News commenter (self-described: Support and verification agents in production), Hacker News comment, published Mar 4, 2026
  86. Issue: LangSmith UI doesn't show the datasets created by SDKHamed Karbasi (hamedkarbasi-haypp), Developer (issue author) (self-described: Datasets and experiments created with the Python SDK), GitHub issue, published Feb 27, 2026
  87. [TypeScript] CRITICAL BUG: AI message duplicated in traces when using Anthropic streaming with finalMessage()BasRizk, developer filing a GitHub issue (self-described: TypeScript app tracing Anthropic streaming calls), GitHub issue, published Feb 7, 2026
  88. LangSmith CLI: Not Just Efficient, Actually Better Than MCPAviad Rozenhek, Developer and author of langsmith-cli (self-described: Debugging and monitoring production LLM runs from the terminal and from Claude Code), dev.to article, published Jan 15, 2026
  89. Issue: Messy Error Logging in LangSmithDaniel (dast-draftwise), Developer, Draftwise (self-described: Draftwise, OpenAI calls wrapped with wrap_openai and retries), GitHub issue, published Jan 6, 2026
  90. From Tests to Experiments: Evaluating LangGraph Agents with LangSmith and PytestAndrew Larsen, engineer (self-described: Production support agent built with LangGraph; pytest evaluators extended with LangSmith experiments), Medium article, published Dec 28, 2025
  91. Comment on: Critical vulnerability in LangChain - CVE-2025-68664stingraycharles, Hacker News commenter, self-described, Hacker News comment, published Dec 27, 2025
  92. Reflections on building my first LangGraph projectJuha Pellotsalo, Senior engineer (self-described) (self-described: Solo learning project: multi-agent newsroom workflow in LangGraph), dev.to article, published Dec 22, 2025
  93. [langsmith]: LangSmith traces from Claude Code do not expose cost, token usage, or detailed model metadataadhishthite, Developer (issue author) (self-described: Tracing Claude Code sessions into LangSmith), GitHub issue, published Dec 21, 2025
  94. Comment on: Show HN: Sim - Apache-2.0 n8n alternativethreecheese, Hacker News commenter (self-described: Builds agents with LangGraph workflows), Hacker News comment, published Dec 12, 2025
  95. Comment on: Show HN: How to fix AI Agents at the component levelMesterniz, Hacker News commenter (self-described: Multi-component agent built for a write-up), Hacker News comment, published Dec 12, 2025
  96. How Agentic Search Unlocks Legal Research Intelligence at HarveyLysia Li and five co-authors, Harvey (self-described: Harvey Agentic Search for legal research, built on the OpenAI Agents SDK), Company engineering blog, harvey.ai, published Dec 10, 2025
  97. Issue: Bulk Export takes very long time with small number of tracesdast-draftwise, developer filing a GitHub issue (self-described: Exporting LangSmith traces to S3 as Parquet for a data pipeline), GitHub issue, published Oct 29, 2025
  98. Issue: LangSmith tracing does not capture subagent tool calls in Claude Agent SDKzhangjunkang (Z-Jr10-K), Developer, SprintRay (self-described: Claude Agent SDK app with subagents and MCP servers), GitHub issue, published Oct 27, 2025
  99. Comment on: LangChain raises US$125M to build the platform for agent engineeringshcallaway, Hacker News commenter (self-described: Agents on LangGraph TypeScript SDK hosted on LangGraph Platform / Deployments for about a year), Hacker News comment, published Oct 21, 2025
  100. Review of LangSmith by Maryam WarraichMaryam Warraich, Product Hunt (self-described: Own LLM projects taken from idea to production), Product Hunt review, published Oct 5, 2025
  101. Selecting The Right AI Evals ToolHamel Husain, AI evals consultant and course instructor, with panelists Shreya Shankar and Bryan Bischof (self-described: Panel of data scientists watching LangSmith, Braintrust, and Arize Phoenix complete the same evals homework), Independent evaluation, hamel.dev blog, published Oct 1, 2025
  102. Issue: Cost showing up as 0 despite having tokensryanlohyr, developer filing a GitHub issue (self-described: Runs with several OpenAI calls traced to LangSmith), GitHub issue, published Sep 16, 2025
  103. Issue: Memory leakshenriquejsb, Developer (issue author) (self-described: Long-running Python application on LangGraph and LangChain), GitHub issue, published Sep 10, 2025
  104. Langsmith is downAhmad Ilaiwi (Ilaiwi), Forum user (self-described: Team using LangSmith projects), LangChain Forum post, published Sep 9, 2025
  105. Review of LangSmith by Kanishk GuptaKanishk Gupta, Builder of Promptius (self-described: Promptius, built over five months on LangChain, LangGraph and LangSmith), Product Hunt review, published Aug 16, 2025
  106. Comment on: Open SWE by LangChainNeutralCrane, Hacker News commenter, self-described, Hacker News comment, published Aug 11, 2025
  107. Comment on: Open SWE by LangChainNeutralCrane, Hacker News commenter, self-described, Hacker News comment, published Aug 8, 2025
  108. Not able to delete not used Extended Data Retention tracesBob (hubdev), Forum user (self-described: Comparing prompts in LangSmith experiments against a dataset), LangChain Forum post, published Jul 29, 2025
  109. Self-hosted: Langsmith is counting base64 encoded files/images as string tokens, causing massively incorrect token costsShane S (ssmithra), Forum user (self-described: Self-hosted LangSmith, moving into multi-modal inputs), LangChain Forum post, published Jul 29, 2025
  110. Evaluating AI Search: A Practical Framework for Augmented AI SystemsMaitar Asher, Head of Engineering, Tavily (Tavily's open-source LangGraph agent that builds fresh eval datasets for web search from live documents), Conference talk with transcript, AI Engineer World's Fair 2025, published Jul 29, 2025
  111. Comment on: Ask HN: GCP Outage?staletofu, Hacker News commenter, self-described, Hacker News comment, published Jul 18, 2025
  112. Review of LangSmith by Dan BulteelDan Bulteel, Maker of Meet-Ting (self-described: Ting scheduling assistant, early-stage product team), Product Hunt review, published Jul 16, 2025
  113. [Bug] Eval experiment table is empty if OTEL_ENABLED environment variable is setYurii Venher (yurii-ve), Developer, Wix (self-described: Evaluations of Vercel AI SDK calls through OpenTelemetry), GitHub issue, published Jul 11, 2025
  114. Tracing with AI SDK (by Vercel) creates trace with wrong (doubled) total tokens countyurii-ve, developer filing a GitHub issue (self-described: Vercel AI SDK app calling Gemini on Vertex, traced through LangSmith's exporter), GitHub issue, published Jun 23, 2025
  115. Review of LangSmith by Kyle RushKyle Rush, Maker of Astrid: Personal Shopping Agent (self-described: Astrid personal shopping agent; traces, datasets, annotation queues and evals), Product Hunt review, published Jun 22, 2025
  116. Case Study + Deep Dive: Telemedicine Support Agents with LangGraph/MCPDan Mason, Principal, AI, Stride (LangGraph agents Stride built to guide telemedicine patients through at-home treatment by text message), Conference workshop with transcript, AI Engineer World's Fair 2025, published Jun 22, 2025
  117. Ask HN: What tools are you using for AI evals? Everything feels half-bakedfazlerocks, Hacker News poster (self-described: Team running LLMs in production for content generation, customer support and code review assistance), Hacker News post (Ask HN), published Jun 5, 2025
  118. Failed to send compressed multipart ingest: Connection error caused failure to POST https://api.smith.langchain.com/runs/multipart in LangSmith APIerwan-png, developer filing a GitHub issue (self-described: LangGraph app on Ollama and Groq models traced to LangSmith), GitHub issue, published Jun 4, 2025
  119. Comment on: Use the Gemini API with OpenAI Fallback in TypeScriptsenko, Hacker News commenter (self-described: Solo, own thin LLM wrapper), Hacker News comment, published Apr 7, 2025
  120. Issue: Client silently stops posting traces to the API (auto_batch_tracing=True, DISABLE_RUN_COMPRESSION=False)André Menezes (menezesandre), AI engineer (self-described: Python application traced with auto-batch tracing and compression), GitHub issue, published Apr 3, 2025
  121. Duplicate traces through OpenAI agents SDKKarolis Mariunas (kmariunas), Developer (issue author) (self-described: OpenAI Agents SDK app traced to LangSmith), GitHub issue, published Mar 31, 2025
  122. LangSmith: Observability for AI AgentsJohn Capobianco, YouTube creator building AI agents (self-described: Own LangGraph agent project instrumented with @traceable and the OpenAI client wrapper), Video, YouTube, published Mar 9, 2025
  123. The NonBioS LLM Observability PickAmit, NonBioS author (self-described: NonBioS AI Engineer product; runs consume over a million tokens and about a hundred inference calls in five minutes, with sensitive customer data), Company blog post, NonBioS.ai, published Mar 5, 2025
  124. Best evaluation platform for LLMs/agentic frameworks for error analysis?h-portia, Reddit user (self-described: Team running LLM output evals in LangSmith, Python), Reddit post, r/LLMDevs, published Feb 6, 2025
  125. Review of LangSmith by Hannah CraigheadHannah Craighead, startup team member (self-described: Startup; ongoing LLM evaluations with LangSmith evals in GitHub CI/CD), Product Hunt review, published Jan 27, 2025

Jan 2025 to Oct 2026.

110 sources from practitioners, by month and sentiment.

The full readExplore all LangSmith Signals5 praise themes, 5 concerns, 5 points of agreement and 2 disagreements across all three groups, with all 125 sources open to inspect.

Where It Fits

Where does LangSmith belong in the stack?

Open Where It Fits: the Stack Field and the full map

LangSmith is Core across Evaluate and Operate, supports Model and Build, and touches Data.

Business area
Product & Engineering
Function
Software Development
Operating stack
AI Application Platform
Primary role
LLM & Agent Observability, Evaluation, and Deployment
LangSmith beside the rest of its stackThe Stack Field, every product on every layer
FootprintLangSmith across the AI Application Platform stack. Bar height is its role on each layer.

  1. Model

    1. Model APIs: Touches

      Model APIs, touches. LangSmith records application calls to OpenAI, Anthropic, Google, and other providers, including token counts and cost. It supplies no models.

    2. Model gateway: Supports

      Model gateway, supports. The LLM Gateway uses one API key across providers. It adds spend and rate limits, fallbacks, and PII redaction, then records calls in LangSmith traces.

  2. Build

    1. Orchestration: Supports

      Orchestration, supports. LangSmith traces LangGraph, LangChain, and Deep Agents, as well as other frameworks. Those open-source frameworks are separate products. Studio debugs graphs on Agent Server.

    2. Tool use: Supports

      Tool use, supports. Traces record tool calls. Sandboxes isolate agent-generated code, and deployed agents can expose an MCP server.

  3. Data

    1. Retrieval: Touches

      Retrieval, touches. LangSmith records retrieval steps and latency. The application must embed, index, and store documents elsewhere.

  4. Evaluate

    1. Evaluation: Core

      Evaluation, core. Datasets and offline experiments score prompt or model changes before release. LLM-as-a-judge and code evaluators work alongside annotation queues. Online evaluators score production traces.

  5. Operate

    1. Observability: Core

      Observability, core. LangSmith traces LLM apps and agents through SDKs, LangChain integrations, or OpenTelemetry. Cost tracking, dashboards, Insights reports, and alerts use those traces.

    2. Cloud deployment: Supports

      Cloud deployment, supports. LangSmith Deployment runs Serverless or Dedicated Agent Servers in LangChain's cloud, hybrid, BYOC, or standalone setups. Enterprise also supports self-hosting the platform on Kubernetes.

    3. Guardrails: Touches

      Guardrails, touches. LangSmith online evaluators run code or model based checks on traced runs, filtered by tool calls or metadata. They score runs after they finish and block no live requests.

Market mapThe layers LangSmith covers, and who else owns each one.

  1. Evaluation & testing

    CoreEvaluate

  2. Observability & tracing

    CoreOperate

  3. Model gateways & routing

    SupportsModel

  4. Orchestration & agent frameworks

    SupportsBuild

  5. Tool use & integrations

    SupportsBuild

4 more layers on the full map. Core, Supports and Touches describe coverage. They say nothing about quality.

More on LangSmith

  1. GILD ReviewGILD's evaluation, with the buying facts
  2. Research2 pieces
  3. Guides4 guides
  4. Operator Insights9 operator accounts
  5. Where It FitsOn the AI Application Platform stack
  6. Related Products6 products