Observability - official LangChain (LangSmith) server
LangSmith Remote MCP server
LangSmith-hosted MCP server that exposes conversation threads, prompts, runs and traces, datasets, experiments and billing usage from a LangSmith workspace to MCP clients. LangChain (LangSmith) hosts it at https://api.smith.langchain.com/mcp with OAuth or API key auth.
Last verified 15 tools4 sources
Install
Claude Code
About Claude Codeclaude mcp add --transport http -s user langsmith https://api.smith.langchain.com/mcpCursor
About Cursor{
"mcpServers": {
"LangSmith": {
"url": "https://api.smith.langchain.com/mcp"
}
}
}Generic
{
"mcpServers": {
"langsmith": {
"type": "http",
"url": "https://api.smith.langchain.com/mcp"
}
}
}Tools
get_thread_history- Get message history for a conversation thread, with character-based pagination.
list_prompts- List prompts with optional filtering by visibility (public/private) and limit.
get_prompt_by_name- Get a single prompt by exact name (details and template).
push_prompt- Documentation-only: how to create and push prompts to LangSmith.
fetch_runs- Fetch runs (traces, tools, chains) from one or more projects with filters, FQL and ordering.
list_projects- List projects with optional filtering by name, dataset, and detail level.
list_datasets- List datasets with filtering by ID, type, name, or metadata.
list_examples- List examples from a dataset by dataset ID/name or example IDs.
read_dataset- Read one dataset by ID or name.
read_example- Read one example by ID, with optional as_of version.
create_dataset- Documentation-only: how to create datasets.
update_examples- Documentation-only: how to update dataset examples.
list_experiments- List experiment projects for a dataset, with latency, cost and feedback metrics.
run_experiment- Documentation-only: how to run experiments and evaluations.
get_billing_usage- Get organization billing usage (e.g. trace counts) for a date range.
As documented on October 17, 2026. A running server reports its current list through tools/list.
Notes and caveats
- Regional endpoints: EU https://eu.api.smith.langchain.com/mcp, APAC https://apac.api.smith.langchain.com/mcp, AWS US https://aws.api.smith.langchain.com/mcp; self-hosted (v0.16+, needs a signing JWKS) and BYOC at https://<host>/api/mcp.
- OAuth 2.1 with dynamic client registration for interactive clients, or X-Api-Key header for programmatic use.
- LangChain documents that OpenAI Codex CLI does not work with the Remote MCP (OAuth resource parameter issue) and recommends the LangSmith CLI instead.
- Separately, LangSmith Agent Server deployments expose a /mcp endpoint that turns deployed agents into MCP tools.
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Related reading
- LangChain and LangGraph in Late 2026: What Is New and Who Should Use ItLangChain 1.4 and LangGraph 1.2 added per-call approvals, built-in MCP, node timeouts and DeltaChannel. What shipped since May 2026 and who should pick it.
- LangSmith Fleet Turns Agent Ops Into On-Call WorkLangSmith Fleet turns agent ops into on-call work: the June On-Call Copilot, computer use, traces, Slack interrupts and MCP auth as one operator loop.
- LangChain Rubrics Make Agent Evals Part of the RuntimeLangChain rubrics for Deep Agents bring evals into the agent loop. Self-correction works only when rubrics are versioned, executable and checked by humans.
- How to Build an AI Agent in 2026: A Practical GuideA step-by-step guide to building AI agents that actually work. Choose a framework, define tools, wire up the loop, and ship something real.
- LangChain vs Vercel AI SDK: Which TypeScript AI Framework Should You Use?Two popular frameworks for building AI apps in TypeScript. Here is when to use each and why most Next.js developers should start with the AI SDK.
- What's New in Mastra (Late 2026): Harness, AgentController GA, Eval Gates and MCP 2.xMastra in late 2026: goals, schedules, signals, AgentController GA, eval gates and MCP 2.x, with type-checked TypeScript examples and honest tradeoffs.
FAQ
What does the LangSmith Remote MCP server do?
LangSmith-hosted MCP server that exposes conversation threads, prompts, runs and traces, datasets, experiments and billing usage from a LangSmith workspace to MCP clients. The vendor documents 15 tools, including get_thread_history, list_prompts, get_prompt_by_name and push_prompt.
How do I add the LangSmith Remote MCP server to Claude Code?
Run claude mcp add --transport http -s user langsmith https://api.smith.langchain.com/mcp, copied from LangChain (LangSmith)'s docs. This page also has snippets for Cursor and Generic.
Does the LangSmith Remote MCP server need authentication?
Yes, OAuth or API key. Transport: Streamable HTTP. Status: Unlabelled, last checked October 17, 2026.
Sources
Last verified against 4 LangChain (LangSmith) pages, then re-checked independently.
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