> ## Documentation Index
> Fetch the complete documentation index at: https://docs.latitude.so/llms.txt
> Use this file to discover all available pages before exploring further.

# LangSmith

> Import historical runs from a LangSmith project, including conversation grouping.

## Overview

This guide shows you how to import your **LangSmith** history into Latitude. Latitude reads
the runs in a LangSmith project and maps them to Latitude traces and spans.

<Check>
  Importing only reads from LangSmith. Nothing is changed or deleted at the source.
</Check>

***

## Requirements

* A **LangSmith project** with the history you want to import
* A LangSmith **API key** (`lsv2_pt_…`)
* Your LangSmith **region** — GCP EU, GCP US, GCP APAC or AWS US
* Your **workspace id**, if your account has more than one workspace

***

## Steps

<Steps>
  <Step title="Create an API key in LangSmith">
    In LangSmith, open **Settings → API keys** and create a key. If your account has
    several workspaces, also copy the id of the one you are importing from.
  </Step>

  <Step title="Connect">
    In Latitude, go to **Project settings → Imports**, choose **LangSmith** and your
    region, enter the API key (and workspace id, if you have one), then press
    **Test connection**.
  </Step>

  <Step title="Preview and start">
    Pick the LangSmith project, set the time range, trace limit and **session metadata
    key** — see below — check the preview, then press **Start import**.
  </Step>
</Steps>

***

## Sessions need a metadata key

In LangSmith, `session_id` identifies the **project**, not a conversation, so Latitude
reads the conversation id from run metadata instead: it looks under `extra.metadata` for
the key you name, defaulting to `thread_id`. If no run carries the key, each trace becomes
its own session and turns will not group into conversations.

<Check>
  The preview tells you which key it used and warns you if no run in the sample carried
  it — worth checking before a large import.
</Check>

***

## LangSmith specifics

* Your region is the host you sign in on: `smith.langchain.com` is GCP US,
  `eu.smith.langchain.com` is GCP EU, and so on. Keys do not cross regions.
* Runs are imported newest first, so a capped import keeps your most recent traces.
* LangSmith's rate limits are the tightest of the three platforms, so a large import takes
  a while — it is paced deliberately and runs in the background.

***

## Seeing your traces

Once imported, traces appear in your project's **Traces** view like any live trace, marked
with `import.*` metadata naming LangSmith and their original ids.