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

# Braintrust

> Give the Sazabi agent tools to query your Braintrust experiments, datasets, prompts, and logs directly from agent conversations.

[All Braintrust integration capabilities](https://docs.sazabi.com/catalogs/integrations/braintrust)

## About

Braintrust is an MCP connector that gives the Sazabi agent tools to query your Braintrust experiments, datasets, prompts, and logs. Braintrust hosts an MCP server at `https://api.braintrust.dev/mcp` (US) or `https://api-eu.braintrust.dev/mcp` (EU) over Streamable HTTP. You supply a Braintrust API key, which Sazabi sends as a Bearer credential in the `Authorization` header. Once connected, the agent can browse and query your Braintrust projects; write operations are governed by the per-connection read-only toggle.

**What the agent can do:**

* Query experiments, evals, and their scores
* Browse datasets and logged traces
* Inspect prompts and project configuration

## Prerequisites

* A Braintrust account
* A Braintrust API key from [Settings > API keys](https://www.braintrust.dev/app/settings/api-keys)

## Set up in the dashboard

Configure connectors in the dashboard under [**Settings > MCP connectors**](https://app.sazabi.com/settings/mcp-connectors).

**Step 1**

### Open the connector

Find Braintrust in [**Settings > MCP connectors**](https://app.sazabi.com/settings/mcp-connectors).

**Step 2**

### Add your key

Paste your Braintrust API key; Sazabi sends it as a Bearer credential in the `Authorization` header to Braintrust's hosted MCP endpoint. Create a key at [Settings > API keys](https://www.braintrust.dev/app/settings/api-keys). Also select your data plane — **US** (`https://api.braintrust.dev/mcp`) or **EU** (`https://api-eu.braintrust.dev/mcp`) — to match where your Braintrust data lives.

## Set up with the CLI

Braintrust authenticates with a Braintrust API key. With the [Sazabi CLI](https://docs.sazabi.com/reference/cli.md) installed and authenticated (see [`sazabi mcp-connectors` reference](https://docs.sazabi.com/reference/cli/mcp-connectors)), connect it in one command, passing the credential as a header:

```bash theme={"system"}
sazabi mcp-connectors connect braintrust --header "Authorization=Bearer <api-key>"
```

The CLI connects to the MCP server at once and prints the connection with the tools it discovered; a credential the server rejects is reported, and the connection is left needing attention. Use `NAME=@<file>` to read a value from a file, or `--header-file <file.json>` for a JSON object of header names and values. To rotate the stored credentials later, use `sazabi mcp-connectors update-credentials <connection-id>`; find the connection ID with `sazabi mcp-connectors list`.

## Verify

Open the connector's connection page under [**Settings > MCP connectors**](https://app.sazabi.com/settings/mcp-connectors) and confirm Sazabi lists the tools it discovered. Then, in a thread, ask the agent to use one of those tools and confirm it runs. If no tools appear, confirm the key is correct and the selected data plane matches where your data lives.

## Troubleshooting

**No tools discovered** — Check that the API key is valid and the data plane (US or EU) matches your Braintrust account region.

**Connection shows needs attention** — The key may have expired or been revoked; reconnect from [**Settings > MCP connectors**](https://app.sazabi.com/settings/mcp-connectors).

## Further reading

> [card] [Agent tools](https://docs.sazabi.com/guides/investigate/agent-tools.md)
>
> How the agent uses connector tools.

> [card] [MCP connectors](https://docs.sazabi.com/catalogs/mcp-connectors.md)
>
> Browse the connector catalog.


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