> ## 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.

# Langfuse

> Import historical traces and observations from Langfuse Cloud.

## Overview

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

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

***

## Requirements

* A **Langfuse Cloud project** with the history you want to import
* A Langfuse **public key** (`pk-lf-…`) and **secret key** (`sk-lf-…`) for that project
* Your Langfuse **region** — EU, US, Japan or HIPAA US

***

## Steps

<Steps>
  <Step title="Create an API key pair in Langfuse">
    In Langfuse, open **Settings → API keys** for the project you are importing from and
    create a key pair. Copy both keys.
  </Step>

  <Step title="Connect">
    In Latitude, go to **Project settings → Imports**, choose **Langfuse** and your region,
    enter both keys, then press **Test connection**.
  </Step>

  <Step title="Preview and start">
    Pick the Langfuse project, set the time range and trace limit, check the preview, then
    press **Start import**.
  </Step>
</Steps>

***

## Langfuse specifics

* Sessions, users, tags, metadata, messages, tool calls, token usage and cost all map
  directly — nothing needs configuring in Langfuse.
* Prompt references (`promptName`, `promptVersion`) land in span metadata, since Latitude
  has no prompt registry.
* Langfuse Cloud regions are fully separate deployments: keys from another region will fail
  the connection test. Pick the one you signed up in.

***

## Seeing your traces

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