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

Set up in the dashboard

Configure connectors in the dashboard under Settings > MCP connectors.

Set up with the CLI

Braintrust authenticates with a Braintrust API key, and sazabi mcp-connectors connect only supports OAuth providers — so set up this connector in the dashboard first (above). Once it's connected, the Sazabi CLI can inspect and manage it (installed and authenticated — see sazabi mcp-connectors reference):

sazabi mcp-connectors list
sazabi mcp-connectors details <connection-id>

Find the connection ID with sazabi mcp-connectors list. To rotate the stored credentials later, use sazabi mcp-connectors update-credentials <connection-id>.

Verify

Open the connector's connection page under 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Connection shows needs attention — The key may have expired or been revoked; reconnect from Settings 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.

Further reading