How to integrate Blocknative MCP with Claude Code

GET STARTED FOR FREE
Framework Integration Gradient
Blocknative Logo
Claude Code Logo
divider

Introduction

Manage your Blocknative directly from Claude Code with zero worries about OAuth hassles, API-breaking issues, or reliability and security concerns.

You can do this in two different ways:

  1. Via Rube - Direct and easiest approach
  2. Via Composio SDK - Programmatic approach with more control

Why Rube?

Rube is a universal MCP server with access to 850+ SaaS apps. It ensures just-in-time tool loading so Claude can access the tools it needs, a remote workbench for programmatic tool calling and handling large tool responses out of the LLM context window, ensuring the LLM context window remains clean.

Connect Blocknative to Claude Code with Rube

1. Get the MCP URL

Copy and paste the below command in Claude Code to add Rube MCP.

Terminal

2. Authenticate Rube

Run /mcp to view Rube

bash
/mcp
Run /mcp to view Rube in Claude Code
Click on Rube to authenticate
Authentication flow complete

3. Ensure it's connected

Run /mcp again to verify the connection. Now, do whatever you want with Claude Code and Blocknative.

Rube connected successfully

Supported Tools & Triggers

Tools
Configure Mempool FiltersTool to configure filters and abi decoding for ethereum mempool transactions.
Get Gas Price DistributionTool to retrieve the current mempool gas price distribution breakdown.
Get Gas OraclesTool to retrieve metadata on supported gas oracles per chain.
Get Gas PricesTool to fetch gas price estimates for specific inclusion probabilities.
Get Supported ChainsTool to retrieve supported chains metadata.
Get Base Fee EstimatesTool to get real-time predictions for base fee and blob base fee for the next 5 blocks.
Subscribe MultichainTool to generate websocket subscription details for events across multiple chains.
Subscribe Transaction HashTool to subscribe to transaction state change events of an ethereum transaction hash.
Unsubscribe MultichainTool to unsubscribe from events across multiple chains using the multichain sdk.
Unsubscribe Transaction HashTool to unsubscribe from transaction state change events for an ethereum transaction hash.

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.

Connecting Blocknative via Tool Router

Tool Router is the underlying tech that powers Rube. It's a universal gateway that does everything Rube does but with much more programmatic control. You can programmatically generate an MCP URL with the app you need (here Blocknative) for even more tool search precision. It's secure and reliable.

How the Tool Router works

The Tool Router 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

Prerequisites

Before starting, make sure you have:
  • Claude Pro, Max, or API billing enabled Anthropic account
  • Composio API Key
  • A Blocknative account
  • Basic knowledge of Python or TypeScript

Install Claude Code

bash
# macOS, Linux, WSL
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

# Windows CMD
curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd

To install Claude Code, use one of the following methods based on your operating system:

Set up Claude Code

bash
cd your-project-folder
claude

Open a terminal, go to your project folder, and start Claude Code:

  • Claude Code will open in your terminal
  • Follow the prompts to sign in with your Anthropic account
  • Complete the authentication flow
  • Once authenticated, you can start using Claude Code
Claude Code initial setup showing sign-in prompt
Claude Code terminal after successful login

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here

Create a .env file in your project root with the following variables:

  • COMPOSIO_API_KEY authenticates with Composio (get it from Composio dashboard)
  • USER_ID identifies the user for session management (use any unique identifier)

Install Composio library

pip install composio-core python-dotenv

Install the Composio Python library to create MCP sessions.

  • composio-core provides the core Composio functionality
  • python-dotenv loads environment variables from your .env file

Generate Composio MCP URL

import os
from composio import Composio
from dotenv import load_dotenv

load_dotenv()

COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
USER_ID = os.getenv("USER_ID")

composio_client = Composio(api_key=COMPOSIO_API_KEY)

composio_session = composio_client.create(
    user_id=USER_ID,
    toolkits=["blocknative"],
)

COMPOSIO_MCP_URL = composio_session.mcp.url

print(f"MCP URL: {COMPOSIO_MCP_URL}")
print(f"\nUse this command to add to Claude Code:")
print(f'claude mcp add --transport http blocknative-composio "{COMPOSIO_MCP_URL}" --headers "X-API-Key:{COMPOSIO_API_KEY}"')

Create a script to generate a Composio MCP URL for Blocknative. This URL will be used to connect Claude Code to Blocknative.

What's happening:
  • We import the Composio client and load environment variables
  • Create a Composio instance with your API key
  • Call create() to create a Tool Router session for Blocknative
  • The returned mcp.url is the MCP server URL that Claude Code will use
  • The script prints this URL so you can copy it

Run the script and copy the MCP URL

python generate_mcp_url.py

Run your Python script to generate the MCP URL.

  • The script connects to Composio and creates a Tool Router session
  • It prints the MCP URL and the exact command you need to run
  • Copy the entire claude mcp add command from the output

Add Blocknative MCP to Claude Code

bash
claude mcp add --transport http blocknative-composio "YOUR_MCP_URL_HERE" --headers "X-API-Key:YOUR_COMPOSIO_API_KEY"

# Then restart Claude Code
exit
claude

In your terminal, add the MCP server using the command from the previous step. The command format is:

  • claude mcp add registers a new MCP server with Claude Code
  • --transport http specifies that this is an HTTP-based MCP server
  • The server name (blocknative-composio) is how you'll reference it
  • The URL points to your Composio Tool Router session
  • --headers includes your Composio API key for authentication

After running the command, close the current Claude Code session and start a new one for the changes to take effect.

Verify the installation

bash
claude mcp list

Check that your Blocknative MCP server is properly configured.

  • This command lists all MCP servers registered with Claude Code
  • You should see your blocknative-composio entry in the list
  • This confirms that Claude Code can now access Blocknative tools

If everything is wired up, you should see your blocknative-composio entry listed:

Claude Code MCP list showing the toolkit MCP server

Authenticate Blocknative

The first time you try to use Blocknative tools, you'll be prompted to authenticate.

  • Claude Code will detect that you need to authenticate with Blocknative
  • It will show you an authentication link
  • Open the link in your browser (or copy/paste it)
  • Complete the Blocknative authorization flow
  • Return to the terminal and start using Blocknative through Claude Code

Once authenticated, you can ask Claude Code to perform Blocknative operations in natural language. For example:

  • "Monitor transaction status for a given hash"
  • "Fetch current Ethereum gas price distribution"
  • "List all supported blockchains for monitoring"

Complete Code

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

import os
from composio import Composio
from dotenv import load_dotenv

load_dotenv()

COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
USER_ID = os.getenv("USER_ID")

composio_client = Composio(api_key=COMPOSIO_API_KEY)

composio_session = composio_client.create(
    user_id=USER_ID,
    toolkits=["blocknative"],
)

COMPOSIO_MCP_URL = composio_session.mcp.url

print(f"MCP URL: {COMPOSIO_MCP_URL}")
print(f"\nUse this command to add to Claude Code:")
print(f'claude mcp add --transport http blocknative-composio "{COMPOSIO_MCP_URL}" --headers "X-API-Key:{COMPOSIO_API_KEY}"')

Conclusion

You've successfully integrated Blocknative with Claude Code using Composio's MCP server. Now you can interact with Blocknative directly from your terminal using natural language commands.

Key features of this setup:

  • Terminal-native experience without switching contexts
  • Natural language commands for Blocknative operations
  • Secure authentication through Composio's managed MCP
  • Tool Router for dynamic tool discovery and execution

Next steps:

  • Try asking Claude Code to perform various Blocknative operations
  • Add more toolkits to your Tool Router session for multi-app workflows
  • Integrate this setup into your development workflow for increased productivity

You can extend this by adding more toolkits, implementing custom workflows, or building automation scripts that leverage Claude Code's capabilities.

How to build Blocknative MCP Agent with another framework

OpenAI Agents SDK

OpenAI Agents SDK

Use Blocknative MCP with OpenAI Agents SDK

Claude Agent SDK

Claude Agent SDK

Use Blocknative MCP with Claude Agent SDK

Google ADK

Google ADK

Use Blocknative MCP with Google ADK

LangChain

LangChain

Use Blocknative MCP with LangChain

Vercel AI SDK

Vercel AI SDK

Use Blocknative MCP with Vercel AI SDK

Mastra AI

Mastra AI

Use Blocknative MCP with Mastra AI

LlamaIndex

LlamaIndex

Use Blocknative MCP with LlamaIndex

CrewAI

CrewAI

Use Blocknative MCP with CrewAI

FAQ

What are the differences in Tool Router MCP and Blocknative MCP?

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.

Can I use Tool Router MCP with Claude Code?

Yes, you can. Claude Code 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.

Can I manage the permissions and scopes for Blocknative while using Tool Router?

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.

How safe is my data with Composio Tool Router?

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.

Used by agents from

Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

Never worry about agent reliability

We handle tool reliability, observability, and security so you never have to second-guess an agent action.

Book a call↗Get started for free