LangSmith integration
LangSmith tracing and evaluation API. Query the runs an LLM application produced with filters and full text search, read one run in detail, compute latency, token and cost statistics over a project, manage tracing projects, build datasets and examples for evaluation, and write or read feedback used as evaluation scores. Naming trap worth stating up front: a tracing project is called a session throughout this API, so the project identifier is named session_id and the project resource lives under sessions.
Say what should happen.
The workflow builds itself.
Common LangSmith use cases
- exporting a dataset for an offline run
- exporting every human review of a project
- validating an API key before a batch export
- finding the dataset id before adding examples
- reading the run count and cost of one project
- cleaning up projects created by a test harness
- removing an example that turned out to be wrong
- pulling every failed run of a project for triage
- creating a regression set before wiring an evaluator
- removing a dataset created by a throwaway experiment
What you can do with LangSmith
Each of these is one operation on one endpoint, available both as a workflow step and as a tool an AI agent can call on its own. Nothing bundles several operations into one action, so what a run did stays readable afterwards.
Most endpoints run on the free plan. A few, mainly the ones that publish on your behalf, need a paid plan.
Example, 5 operations
create_exampleCreate examplePOSTAdds an example to a dataset, optionally copied from a production run.delete_exampleDelete exampleDELETEDeletes one example from its dataset.get_exampleGet exampleGETReturns one example with its inputs, reference outputs and metadata.list_examplesList examplesGETLists the examples of a dataset, optionally as of a past version.update_exampleUpdate examplePATCHEdits the inputs, outputs, metadata or split of an example and returns it as it now stands.
Dataset, 4 operations
create_datasetCreate datasetPOSTCreates a dataset that examples and experiments attach to.delete_datasetDelete datasetDELETEDeletes a dataset together with its examples.get_datasetGet datasetGETReturns a dataset with its schemas, example count and experiment count.list_datasetsList datasetsGETLists evaluation datasets with their example counts.
Project, 4 operations
create_projectCreate projectPOSTCreates a tracing project that runs can then be logged into.delete_projectDelete projectDELETEDeletes a tracing project and the runs logged into it.get_projectGet projectGETReturns one tracing project, optionally with its run statistics.list_projectsList projectsGETLists tracing projects, which this API calls sessions, with optional statistics.
Feedback, 2 operations
create_feedbackCreate feedbackPOSTAttaches a score, value, comment or correction inside a tracing project, optionally aimed at one run.list_feedbackList feedbackGETLists feedback attached to runs or projects, filtered by key, source or score.
Run, 2 operations
get_runGet runGETReturns a single run with its inputs, outputs, token usage and cost.query_runsQuery runsPOSTQueries the runs of one or more tracing projects with filters, search and cursor paging.
Info, 1 operation
get_infoGet infoGETReturns the LangSmith version and the ingestion limits of the deployment.
Run stat, 1 operation
get_run_statsGet run statsPOSTReturns run counts, latency and token percentiles, error rate and cost for a filtered set of runs.
Use LangSmith from Claude Code, Cursor or Codex
Connect LangSmith in LiveContext, create an API key in Settings, then add the LiveContext MCP server to your client. Its LangSmith operations become tools the client can call, next to every other integration you connected.
claude mcp add --transport http livecontext https://livecontext.ai/mcp --header "X-API-Key: YOUR_API_KEY"[mcp_servers.livecontext]
url = "https://livecontext.ai/mcp"
[mcp_servers.livecontext.http_headers]
"X-API-Key" = "YOUR_API_KEY"{
"mcpServers": {
"livecontext": {
"type": "http",
"url": "https://livecontext.ai/mcp",
"headers": {
"X-API-Key": "YOUR_API_KEY"
}
}
}
}How to connect LangSmith
- Create your workspace
Sign up free. Nothing to install.
- Connect LangSmith once
Add your LangSmith connection in Settings. Every tool from this integration reuses it, and secrets are encrypted at rest and visible only to you.
- Describe the job in chat
The workflow builds itself in front of you and picks the endpoints it needs. Drag the steps yourself on the canvas whenever you would rather be explicit.
LangSmith integration FAQ
What can you do with the LangSmith integration?
LiveContext exposes 19 operations on LangSmith, covering example, dataset, project and feedback. Common uses include exporting a dataset for an offline run, exporting every human review of a project and validating an API key before a batch export.
