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

# Environment Variables

> Environment variables customers set when connecting an agent to Kindred.

Set these in the agent you are connecting to Kindred.

## Required

| Variable              | Required | Description                                                 |
| --------------------- | -------- | ----------------------------------------------------------- |
| `LANGFUSE_PUBLIC_KEY` | Yes      | Langfuse project public key.                                |
| `LANGFUSE_SECRET_KEY` | Yes      | Langfuse project secret key.                                |
| `LANGFUSE_HOST`       | Yes      | Langfuse host, for example `https://us.cloud.langfuse.com`. |
| `KINDRED_AGENT_ID`    | Yes      | Kindred agent id copied from the agent registration page.   |

```bash theme={null}
LANGFUSE_PUBLIC_KEY=pk-lf-...
LANGFUSE_SECRET_KEY=sk-lf-...
LANGFUSE_HOST=https://us.cloud.langfuse.com
KINDRED_AGENT_ID=agt_...
```

## Replay fields

You usually do not set replay fields manually. Kindred sends them to your replay endpoint when you click **Run**.

Your replay endpoint should preserve these fields in Langfuse metadata if they appear in the request:

* `kindred_replay_run_id`
* `kindred_original_session_id`
* `kindred_include_prior_context`
* `kindred_turn_trace_id`
* `is_replay`