How to integrate Blocknative MCP with Autogen

This guide walks you through connecting Blocknative to AutoGen using the Composio tool router. By the end, you'll have a working Blocknative agent that can monitor transaction status for a given hash, fetch current ethereum gas price distribution, list all supported blockchains for monitoring through natural language commands. This guide will help you understand how to give your AutoGen agent real control over a Blocknative account through Composio's Blocknative MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Blocknative delivers real-time mempool monitoring and transaction management for public blockchains. Instantly track pending transactions and optimize blockchain interactions with live data.

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Introduction

This guide walks you through connecting Blocknative to AutoGen using the Composio tool router. By the end, you'll have a working Blocknative agent that can monitor transaction status for a given hash, fetch current ethereum gas price distribution, list all supported blockchains for monitoring through natural language commands.

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

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

Also integrate Blocknative with

OpenAI Agents SDKClaude Agent SDKClaude CodeClaude CoworkCodexOpenClawHermesCLIGoogle ADKLangChainVercel AI SDKMastra AILlamaIndexCrewAI

TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Install the required dependencies for Autogen and Composio
  • Initialize Composio and create a Tool Router session for Blocknative
  • Wire that MCP URL into Autogen using McpWorkbench and StreamableHttpServerParams
  • Configure an Autogen AssistantAgent that can call Blocknative tools
  • Run a live chat loop where you ask the agent to perform Blocknative operations

What is AutoGen?

Autogen is a framework for building multi-agent conversational AI systems from Microsoft. It enables you to create agents that can collaborate, use tools, and maintain complex workflows.

Key features include:

  • Multi-Agent Systems: Build collaborative agent workflows
  • MCP Workbench: Native support for Model Context Protocol tools
  • Streaming HTTP: Connect to external services through streamable HTTP
  • AssistantAgent: Pre-built agent class for tool-using assistants

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

The Blocknative MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Blocknative account. It provides structured and secure access to real-time mempool data and transaction management features across public blockchains, so your agent can monitor transactions, analyze gas prices, configure filters, and manage blockchain event subscriptions on your behalf.

  • Real-time mempool monitoring: Instruct your agent to subscribe to Ethereum transaction hashes or addresses and receive instant updates on their status and events.
  • Gas price analysis and estimation: Have your agent fetch current gas price distributions, base fee predictions, and inclusion probability estimates to help optimize transaction fees.
  • Customizable event filters: Let your agent configure advanced mempool filters and ABI decoding, so you can track only the events or transactions that matter to your workflow.
  • Multichain event subscriptions: Enable your agent to subscribe or unsubscribe to transaction and account events across multiple supported blockchains using the Blocknative multichain SDK.
  • Supported chain discovery: Ask your agent to list and discover which blockchains and gas oracles are available for monitoring and analytics.

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 step08 STEPS
1

Prerequisites

You will need:

  • A Composio API key
  • An OpenAI API key (used by Autogen's OpenAIChatCompletionClient)
  • A Blocknative account you can connect to Composio
  • Some basic familiarity with Autogen and Python async
2

Getting API Keys for OpenAI and Composio

OpenAI API Key
  • Go to the OpenAI dashboard and create an API key. You'll need credits to use the models, or you can connect to another model provider.
  • Keep the API key safe.
Composio API Key
  • Log in to the Composio dashboard.
  • Navigate to your API settings and generate a new API key.
  • Store this key securely as you'll need it for authentication.
3

Install dependencies

bash
pip install composio python-dotenv
pip install autogen-agentchat autogen-ext-openai autogen-ext-tools

Install Composio, Autogen extensions, and dotenv.

What's happening:

  • composio connects your agent to Blocknative via MCP
  • autogen-agentchat provides the AssistantAgent class
  • autogen-ext-openai provides the OpenAI model client
  • autogen-ext-tools provides MCP workbench support

4

Set up environment variables

bash
COMPOSIO_API_KEY=your-composio-api-key
OPENAI_API_KEY=your-openai-api-key
USER_ID=your-user-identifier@example.com

Create a .env file in your project folder.

What's happening:

  • COMPOSIO_API_KEY is required to talk to Composio
  • OPENAI_API_KEY is used by Autogen's OpenAI client
  • USER_ID is how Composio identifies which user's Blocknative connections to use
5

Import dependencies and create Tool Router session

python
import asyncio
import os
from dotenv import load_dotenv
from composio import Composio

from autogen_agentchat.agents import AssistantAgent
from autogen_ext.models.openai import OpenAIChatCompletionClient
from autogen_ext.tools.mcp import McpWorkbench, StreamableHttpServerParams

load_dotenv()

async def main():
    # Initialize Composio and create a Blocknative session
    composio = Composio(api_key=os.getenv("COMPOSIO_API_KEY"))
    session = composio.create(
        user_id=os.getenv("USER_ID"),
        toolkits=["blocknative"]
    )
    url = session.mcp.url
What's happening:
  • load_dotenv() reads your .env file
  • Composio(api_key=...) initializes the SDK
  • create(...) creates a Tool Router session that exposes Blocknative tools
  • session.mcp.url is the MCP endpoint that Autogen will connect to
6

Configure MCP parameters for Autogen

python
# Configure MCP server parameters for Streamable HTTP
server_params = StreamableHttpServerParams(
    url=url,
    timeout=30.0,
    sse_read_timeout=300.0,
    terminate_on_close=True,
    headers={"x-api-key": os.getenv("COMPOSIO_API_KEY")}
)

Autogen expects parameters describing how to talk to the MCP server. That is what StreamableHttpServerParams is for.

What's happening:

  • url points to the Tool Router MCP endpoint from Composio
  • timeout is the HTTP timeout for requests
  • sse_read_timeout controls how long to wait when streaming responses
  • terminate_on_close=True cleans up the MCP server process when the workbench is closed
7

Create the model client and agent

python
# Create model client
model_client = OpenAIChatCompletionClient(
    model="gpt-5",
    api_key=os.getenv("OPENAI_API_KEY")
)

# Use McpWorkbench as context manager
async with McpWorkbench(server_params) as workbench:
    # Create Blocknative assistant agent with MCP tools
    agent = AssistantAgent(
        name="blocknative_assistant",
        description="An AI assistant that helps with Blocknative operations.",
        model_client=model_client,
        workbench=workbench,
        model_client_stream=True,
        max_tool_iterations=10
    )

What's happening:

  • OpenAIChatCompletionClient wraps the OpenAI model for Autogen
  • McpWorkbench connects the agent to the MCP tools
  • AssistantAgent is configured with the Blocknative tools from the workbench
8

Run the interactive chat loop

python
print("Chat started! Type 'exit' or 'quit' to end the conversation.\n")
print("Ask any Blocknative related question or task to the agent.\n")

# Conversation loop
while True:
    user_input = input("You: ").strip()

    if user_input.lower() in ["exit", "quit", "bye"]:
        print("\nGoodbye!")
        break

    if not user_input:
        continue

    print("\nAgent is thinking...\n")

    # Run the agent with streaming
    try:
        response_text = ""
        async for message in agent.run_stream(task=user_input):
            if hasattr(message, "content") and message.content:
                response_text = message.content

        # Print the final response
        if response_text:
            print(f"Agent: {response_text}\n")
        else:
            print("Agent: I encountered an issue processing your request.\n")

    except Exception as e:
        print(f"Agent: Sorry, I encountered an error: {str(e)}\n")
What's happening:
  • The script prompts you in a loop with You:
  • Autogen passes your input to the model, which decides which Blocknative tools to call via MCP
  • agent.run_stream(...) yields streaming messages as the agent thinks and calls tools
  • Typing exit, quit, or bye ends the loop

Complete Code

Here's the complete code to get you started with Blocknative and AutoGen:

python
import asyncio
import os
from dotenv import load_dotenv
from composio import Composio

from autogen_agentchat.agents import AssistantAgent
from autogen_ext.models.openai import OpenAIChatCompletionClient
from autogen_ext.tools.mcp import McpWorkbench, StreamableHttpServerParams

load_dotenv()

async def main():
    # Initialize Composio and create a Blocknative session
    composio = Composio(api_key=os.getenv("COMPOSIO_API_KEY"))
    session = composio.create(
        user_id=os.getenv("USER_ID"),
        toolkits=["blocknative"]
    )
    url = session.mcp.url

    # Configure MCP server parameters for Streamable HTTP
    server_params = StreamableHttpServerParams(
        url=url,
        timeout=30.0,
        sse_read_timeout=300.0,
        terminate_on_close=True,
        headers={"x-api-key": os.getenv("COMPOSIO_API_KEY")}
    )

    # Create model client
    model_client = OpenAIChatCompletionClient(
        model="gpt-5",
        api_key=os.getenv("OPENAI_API_KEY")
    )

    # Use McpWorkbench as context manager
    async with McpWorkbench(server_params) as workbench:
        # Create Blocknative assistant agent with MCP tools
        agent = AssistantAgent(
            name="blocknative_assistant",
            description="An AI assistant that helps with Blocknative operations.",
            model_client=model_client,
            workbench=workbench,
            model_client_stream=True,
            max_tool_iterations=10
        )

        print("Chat started! Type 'exit' or 'quit' to end the conversation.\n")
        print("Ask any Blocknative related question or task to the agent.\n")

        # Conversation loop
        while True:
            user_input = input("You: ").strip()

            if user_input.lower() in ['exit', 'quit', 'bye']:
                print("\nGoodbye!")
                break

            if not user_input:
                continue

            print("\nAgent is thinking...\n")

            # Run the agent with streaming
            try:
                response_text = ""
                async for message in agent.run_stream(task=user_input):
                    if hasattr(message, 'content') and message.content:
                        response_text = message.content

                # Print the final response
                if response_text:
                    print(f"Agent: {response_text}\n")
                else:
                    print("Agent: I encountered an issue processing your request.\n")

            except Exception as e:
                print(f"Agent: Sorry, I encountered an error: {str(e)}\n")

if __name__ == "__main__":
    asyncio.run(main())

Conclusion

You now have an Autogen assistant wired into Blocknative through Composio's Tool Router and MCP. From here you can:
  • Add more toolkits to the toolkits list, for example notion or hubspot
  • Refine the agent description to point it at specific workflows
  • Wrap this script behind a UI, Slack bot, or internal tool
Once the pattern is clear for Blocknative, you can reuse the same structure for other MCP-enabled apps with minimal code changes.
TOOLS

Supported Tools

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

Configure Mempool Filters

Tool to configure filters and ABI decoding for Ethereum mempool transactions.

Get Gas Price Distribution

Tool to retrieve the current mempool gas price distribution breakdown.

Get Gas Oracles

Tool to retrieve metadata on supported gas oracles per chain.

Get Gas Prices

Tool to fetch gas price estimates for specific inclusion probabilities.

Get Supported Chains

Tool to retrieve supported chains metadata.

Get Base Fee Estimates

Get real-time gas fee predictions for Ethereum mainnet's next 5 blocks.

Subscribe Multichain

Generate WebSocket connection details to subscribe to real-time blockchain events (transactions or account activity) across multiple chains via Blocknative's Multichain API.

Subscribe Transaction Hash

Tool to subscribe to transaction state change events of an Ethereum transaction hash.

Unsubscribe Multichain

Tool to unsubscribe from events across multiple chains using the Multichain SDK.

Unsubscribe Transaction Hash

Tool to unsubscribe from transaction state change events for an Ethereum transaction hash.

FRAMEWORKS

How to build Blocknative MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Blocknative MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Blocknative MCP with Claude Agent SDK

Claude Code logo

Claude Code

Use Blocknative MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Blocknative MCP with Claude Cowork

Codex logo

Codex

Use Blocknative MCP with Codex

OpenClaw logo

OpenClaw

Use Blocknative MCP with OpenClaw

Hermes logo

Hermes

Use Blocknative MCP with Hermes

CLI logo

CLI

Use Blocknative MCP with CLI

Google ADK logo

Google ADK

Use Blocknative MCP with Google ADK

LangChain logo

LangChain

Use Blocknative MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Blocknative MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Blocknative MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Blocknative MCP with LlamaIndex

CrewAI logo

CrewAI

Use Blocknative MCP with CrewAI

FAQ

Frequently asked questions

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

Yes, you can. Autogen 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 Blocknative tools.

Yes, absolutely. You can configure which Blocknative 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 Blocknative data and credentials are handled as safely as possible.

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