How to integrate Braintrust MCP with Google ADK

This guide walks you through connecting Braintrust to Google ADK using the Composio tool router. By the end, you'll have a working Braintrust agent that can compare failed evaluations across recent experiments, create dataset from production failure logs, summarize latency spikes in braintrust traces through natural language commands. This guide will help you understand how to give your Google ADK agent real control over a Braintrust account through Composio's Braintrust MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Braintrust is an AI engineering platform for prompts, datasets, experiments, evaluations, observability, and production AI apps. Use it to ship better AI systems with faster debugging, clearer evals, and tighter feedback loops.

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Introduction

This guide walks you through connecting Braintrust to Google ADK using the Composio tool router. By the end, you'll have a working Braintrust agent that can compare failed evaluations across recent experiments, create dataset from production failure logs, summarize latency spikes in braintrust traces through natural language commands.

This guide will help you understand how to give your Google ADK agent real control over a Braintrust account through Composio's Braintrust MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate Braintrust with

OpenAI Agents SDKClaude Agent SDKClaude CodeClaude CoworkCodexOpenClawHermesCLILangChainVercel AI SDKMastra AILlamaIndexCrewAI

TL;DR

Here's what you'll learn:
  • Get a Braintrust account set up and connected to Composio
  • Install the Google ADK and Composio packages
  • Create a Composio Tool Router session for Braintrust
  • Build an agent that connects to Braintrust through MCP
  • Interact with Braintrust using natural language

What is Google ADK?

Google ADK (Agents Development Kit) is Google's framework for building AI agents powered by Gemini models. It provides tools for creating agents that can use external services through the Model Context Protocol.

Key features include:

  • Gemini Integration: Native support for Google's Gemini models
  • MCP Toolset: Built-in support for Model Context Protocol tools
  • Streamable HTTP: Connect to external services through streamable HTTP
  • CLI and Web UI: Run agents via command line or web interface

What is the Braintrust MCP server, and what's possible with it?

The Braintrust MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Braintrust account. It provides structured and secure access to your projects, prompts, datasets, experiments, evaluations, and observability data, so your agent can create resources, manage evaluation data, inspect events, query results, and update configurations on your behalf.

  • Project and resource management: Have your agent create, list, update, or delete Braintrust projects and manage the experiments, datasets, and prompts within them.
  • Dataset creation and maintenance: Let the agent create datasets, add batches of examples, revise dataset details, and summarize their contents and metrics.
  • Experiment tracking and evaluation: Direct your agent to create experiments, add result events, update experiment details, and retrieve aggregate evaluation summaries.
  • Prompt configuration: Instruct your agent to create versioned prompts and update their metadata or configuration without running them.
  • Observability and data analysis: Have your agent fetch recent project, experiment, or dataset events and run read-only queries over Braintrust data to investigate results.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

  1. Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
  2. Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
  3. Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS
1

Prerequisites

Before starting, make sure you have:
  • A Google API key for Gemini models
  • A Composio account and API key
  • Python 3.9 or later installed
  • Basic familiarity with Python
2

Getting API Keys for Google and Composio

Google API Key
  • Go to Google AI Studio and create an API key.
  • Copy the key and keep it safe. You will put this in GOOGLE_API_KEY.
Composio API Key and User ID
  • Log in to the Composio dashboard.
  • Go to Settings → API Keys and copy your Composio API key. Use this for COMPOSIO_API_KEY.
  • Decide on a stable user identifier to scope sessions, often your email or a user ID. Use this for COMPOSIO_USER_ID.
3

Install dependencies

bash
pip install google-adk composio python-dotenv

Inside your virtual environment, install the required packages.

What's happening:

  • google-adk is Google's Agents Development Kit
  • composio connects your agent to Braintrust via MCP
  • python-dotenv loads environment variables
4

Set up ADK project

bash
adk create my_agent

Set up a new Google ADK project.

What's happening:

  • This creates an agent folder with a root agent file and .env file
5

Set environment variables

bash
GOOGLE_API_KEY=your-google-api-key
COMPOSIO_API_KEY=your-composio-api-key
COMPOSIO_USER_ID=your-user-id-or-email

Save all your credentials in the .env file.

What's happening:

  • GOOGLE_API_KEY authenticates with Google's Gemini models
  • COMPOSIO_API_KEY authenticates with Composio
  • COMPOSIO_USER_ID identifies the user for session management
6

Import modules and validate environment

python
import os
import warnings

from composio import Composio
from dotenv import load_dotenv
from google.adk.agents.llm_agent import Agent
from google.adk.tools.mcp_tool.mcp_session_manager import StreamableHTTPConnectionParams
from google.adk.tools.mcp_tool.mcp_toolset import McpToolset

load_dotenv()

warnings.filterwarnings("ignore", message=".*BaseAuthenticatedTool.*")

GOOGLE_API_KEY = os.getenv("GOOGLE_API_KEY")
COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
COMPOSIO_USER_ID = os.getenv("COMPOSIO_USER_ID")

if not GOOGLE_API_KEY:
    raise ValueError("GOOGLE_API_KEY is not set in the environment.")
if not COMPOSIO_API_KEY:
    raise ValueError("COMPOSIO_API_KEY is not set in the environment.")
if not COMPOSIO_USER_ID:
    raise ValueError("COMPOSIO_USER_ID is not set in the environment.")
What's happening:
  • os reads environment variables
  • Composio is the main Composio SDK client
  • GoogleProvider declares that you are using Google ADK as the agent runtime
  • Agent is the Google ADK LLM agent class
  • McpToolset lets the ADK agent call MCP tools over HTTP
7

Create Composio client and Tool Router session

python
composio_client = Composio(api_key=COMPOSIO_API_KEY)

composio_session = composio_client.create(
    user_id=COMPOSIO_USER_ID,
    toolkits=["braintrust"],
)

COMPOSIO_MCP_URL = composio_session.mcp.url,
print(f"Composio MCP URL: {COMPOSIO_MCP_URL}")
What's happening:
  • Authenticates to Composio with your API key
  • Declares Google ADK as the provider
  • Spins up a short-lived MCP endpoint for your user and selected toolkit
  • Stores the MCP HTTP URL for the ADK MCP integration
8

Set up the McpToolset and create the Agent

python
composio_toolset = McpToolset(
    connection_params=StreamableHTTPConnectionParams(
        url=COMPOSIO_MCP_URL,
        headers={"x-api-key": COMPOSIO_API_KEY}
    )
)

root_agent = Agent(
    model="gemini-2.5-flash",
    name="composio_agent",
    description="An agent that uses Composio tools to perform actions.",
    instruction=(
        "You are a helpful assistant connected to Composio. "
        "You have the following tools available: "
        "COMPOSIO_SEARCH_TOOLS, COMPOSIO_MULTI_EXECUTE_TOOL, "
        "COMPOSIO_MANAGE_CONNECTIONS, COMPOSIO_REMOTE_BASH_TOOL, COMPOSIO_REMOTE_WORKBENCH. "
        "Use these tools to help users with Braintrust operations."
    ),
    tools=[composio_toolset],
)

print("\nAgent setup complete. You can now run this agent directly ;)")
What's happening:
  • Connects the ADK agent to the Composio MCP endpoint through McpToolset
  • Uses Gemini as the model powering the agent
  • Lists exact tool names in instruction to reduce misnamed tool calls
9

Run the agent

bash
# Run in CLI mode
adk run my_agent

# Or run in web UI mode
adk web

Execute the agent from the project root. The web command opens a web portal where you can chat with the agent.

What's happening:

  • adk run runs the agent in CLI mode
  • adk web . opens a web UI for interactive testing

Complete Code

Here's the complete code to get you started with Braintrust and Google ADK:

python
import os
import warnings

from composio import Composio
from composio_google import GoogleProvider
from dotenv import load_dotenv
from google.adk.agents.llm_agent import Agent
from google.adk.tools.mcp_tool.mcp_session_manager import StreamableHTTPConnectionParams
from google.adk.tools.mcp_tool.mcp_toolset import McpToolset

load_dotenv()
warnings.filterwarnings("ignore", message=".*BaseAuthenticatedTool.*")

GOOGLE_API_KEY = os.getenv("GOOGLE_API_KEY")
COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
COMPOSIO_USER_ID = os.getenv("COMPOSIO_USER_ID")

if not GOOGLE_API_KEY:
    raise ValueError("GOOGLE_API_KEY is not set in the environment.")
if not COMPOSIO_API_KEY:
    raise ValueError("COMPOSIO_API_KEY is not set in the environment.")
if not COMPOSIO_USER_ID:
    raise ValueError("COMPOSIO_USER_ID is not set in the environment.")

composio_client = Composio(api_key=COMPOSIO_API_KEY, provider=GoogleProvider())

composio_session = composio_client.create(
    user_id=COMPOSIO_USER_ID,
    toolkits=["braintrust"],
)

COMPOSIO_MCP_URL = composio_session.mcp.url


composio_toolset = McpToolset(
    connection_params=StreamableHTTPConnectionParams(
        url=COMPOSIO_MCP_URL,
        headers={"x-api-key": COMPOSIO_API_KEY}
    )
)

root_agent = Agent(
    model="gemini-2.5-flash",
    name="composio_agent",
    description="An agent that uses Composio tools to perform actions.",
    instruction=(
        "You are a helpful assistant connected to Composio. "
        "You have the following tools available: "
        "COMPOSIO_SEARCH_TOOLS, COMPOSIO_MULTI_EXECUTE_TOOL, "
        "COMPOSIO_MANAGE_CONNECTIONS, COMPOSIO_REMOTE_BASH_TOOL, COMPOSIO_REMOTE_WORKBENCH. "
        "Use these tools to help users with Braintrust operations."
    ),  
    tools=[composio_toolset],
)

print("\nAgent setup complete. You can now run this agent directly ;)")

Conclusion

You've successfully integrated Braintrust with the Google ADK through Composio's MCP Tool Router. Your agent can now interact with Braintrust using natural language commands.

Key takeaways:

  • The Tool Router approach dynamically routes requests to the appropriate Braintrust tools
  • Environment variables keep your credentials secure and separate from code
  • Clear agent instructions reduce tool calling errors
  • The ADK web UI provides an interactive interface for testing and development

You can extend this setup by adding more toolkits to the toolkits array in your session configuration.

TOOLS

Supported Tools

Every Braintrust action and event your agent gets out of the box.

Create Dataset

Create a named dataset under a Braintrust project, or return the existing dataset unchanged when its name already exists in that project.

Create Experiment

Create an experiment under a Braintrust project.

Create Project

Create a Braintrust project, or return the existing project unchanged when its name already exists.

Create Prompt

Upsert a versioned prompt configuration under a Braintrust project without invoking it.

Delete Project

Soft-delete a Braintrust project and return its deletion state.

Delete Experiment, Dataset, or Prompt

Delete one Braintrust experiment, dataset, or prompt by UUID for explicit lifecycle cleanup.

Fetch Events

Fetch one newest-to-oldest page of project log, experiment, or dataset events.

Get Braintrust Resource

Get one project, experiment, dataset, prompt, or function by UUID.

Insert Dataset Events

Upsert a batch of examples into an existing Braintrust dataset.

Insert Experiment Events

Upsert a batch of result events into an existing Braintrust experiment.

List Braintrust Resources

List and filter one page of projects, experiments, datasets, prompts, or functions visible to the connected Braintrust API key.

Query Braintrust Data

Run one bounded synchronous read-only BTQL query over Braintrust project logs, an experiment, or a dataset.

Summarize Experiment or Dataset

Return metadata and optional aggregate summaries for one Braintrust experiment or dataset.

Update Dataset

Update the name, description, tags, or metadata of a Braintrust dataset.

Update Experiment

Update selected metadata and linkage fields on a Braintrust experiment.

Update Project

Update selected fields of a Braintrust project.

Update Prompt

Update a Braintrust prompt's metadata or configuration without invoking it.

FRAMEWORKS

How to build Braintrust MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Braintrust MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Braintrust MCP with Claude Agent SDK

Claude Code logo

Claude Code

Use Braintrust MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Braintrust MCP with Claude Cowork

Codex logo

Codex

Use Braintrust MCP with Codex

OpenClaw logo

OpenClaw

Use Braintrust MCP with OpenClaw

Hermes logo

Hermes

Use Braintrust MCP with Hermes

CLI logo

CLI

Use Braintrust MCP with CLI

LangChain logo

LangChain

Use Braintrust MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Braintrust MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Braintrust MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Braintrust MCP with LlamaIndex

CrewAI logo

CrewAI

Use Braintrust MCP with CrewAI

FAQ

Frequently asked questions

With a standalone Braintrust MCP server, the agents and LLMs can only access a fixed set of Braintrust tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Braintrust and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. Google ADK fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Braintrust tools.

Yes, absolutely. You can configure which Braintrust scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Braintrust data and credentials are handled as safely as possible.

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