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

# Braintrust

> Connect selected Braintrust projects so Tensile can import trace logs for workflow discovery and evidence review.

Connect Braintrust when the traces you want to evaluate are already in Braintrust.
Tensile reads logs from the selected projects, backfills from the configured date,
and continues syncing through its connector. Source identity is retained where
the provider supplies it.

## Connect one or more projects

1. In Braintrust, create an API key that can read the projects you intend to
   connect. Copy the key and the project IDs.
2. In Tensile, open **Settings → Connections → Braintrust**. Only organization
   owners and admins can manage connections.
3. Enter the Braintrust **Host**. For Braintrust cloud, the default is
   `https://api.braintrust.dev`; use your configured API URL for a self-hosted
   instance.
4. Enter the **API key** and one or more **Project ids**. Put one project ID
   per line or separate them with commas.
5. Review the **Customer-id metadata key** (`customer_id` by default) and
   **Session-id metadata key** (`session_id` by default). The session key groups
   spans into a session when present; otherwise Tensile groups from the root span.
6. Set **Backfill from** to an ISO date to limit the initial history. Leave it
   blank to request all available history.
7. Select **Connect** or **Update** and check the connection status in Settings.

When updating a saved connection, leave the API key field blank to keep the
existing key. Keep the key private and grant only the read access required for
the projects you selected.

## What happens to imported traces

The connector maps Braintrust trace/span records into Tensile sessions and events.
Some recorded Braintrust identity and timing fields support grouping and case
provenance. Availability depends on the source data; Tensile does not infer that a
case came from Braintrust merely because it belongs to a particular customer.

Connecting projects makes eligible trace evidence available to the configured
workspace. It does **not** approve a pack or activate evaluator-pack scoring.
Draft pack review, calibration, sealed validation, and owner approval are
separate steps. See [Evaluator packs](/evaluator-packs).

<Note>
  Use the [data handling guide](/data-governance) to review fields and
  identifiers before connecting a project.
</Note>