How to integrate Blocknative MCP with Hermes

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Introduction

Hermes is a 24/7 autonomous agent that lives on your computer or server — it remembers what it learns and evolves as your usage grows.

This guide explains the easiest and most robust way to connect your Blocknative account to Hermes. You can do this through either Composio Connect CLI or Composio Connect MCP. For personal use we recommend the CLI, but you won't go wrong with MCP either.

Also integrate Blocknative with

What is Composio Connect?

Composio Connect is a consumer offering that lets anyone plug 1,000+ applications directly into their agent harness — including Hermes. It can:

  • Search and load tools from relevant toolkits on-demand, reducing context usage.
  • Chain multiple tools to accomplish complex workflows via a remote workbench, without excessive back-and-forth with the LLM.
  • Manage app authentication end-to-end with zero manual overhead.

Integrating Blocknative with Hermes

Using Composio Connect CLI

1. Install the Composio CLI

Run the install script directly, or paste https://composio.dev/hermes into your Hermes chat box to have it installed for you.

bash
curl -fsSL https://composio.dev/install | bash
Hermes authenticating with Composio

2. Authenticate

Once the CLI is installed, ask Hermes to authenticate with Composio.

3. Connect to Blocknative

Ask your agent to connect to Blocknative, or simply request any Blocknative-related task. Hermes will prompt you to authenticate and authorize access.

4. Done. You're all set with a new Blocknative connection.

Using Composio Connect MCP

1. Get your MCP URL and API Key

Go to dashboard.composio.dev and copy your Connect MCP URL and API key.

Copy MCP URL and API key from Composio dashboard

2. Open the Hermes config file

bash
nano ~/.hermes/config.yaml

3. Add the Composio Connect MCP server

bash
mcp_servers:
  composio:
    url: "https://connect.composio.dev/mcp"
    headers:
      x-consumer-api-key: "YOUR_COMPOSIO_API_KEY"
    connect_timeout: 60
    timeout: 180

Save with Ctrl + O, Enter, then exit with Ctrl + X.

4. Restart your Hermes agent

Once restarted, ask your agent to connect to Blocknative or request any Blocknative-related task. It will prompt you to authenticate and authorize access.

5. Done!

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.

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.

Way Forward

With Blocknative connected, Hermes can now act on your behalf whenever it detects a relevant task or you ask it to.

From here, you can extend Hermes further:

  • Connect more apps: Calendar, Slack, Notion, Linear, and hundreds of others are available through the same Composio Connect setup. Each new integration compounds what Hermes can do for you.
  • Build workflows across tools: Once multiple apps are connected, Hermes can chain actions together — turn an email into a calendar invite, a Slack message into a Linear ticket, or a meeting note into a follow-up draft.
  • Let it learn your patterns: The more you use Hermes, the better it gets at anticipating how you'd handle recurring tasks. Give it feedback on drafts and decisions, and it will adapt.

If you run into trouble or want to share what you've built, join the community or check out the Docs for deeper configuration options.

How to build Blocknative MCP Agent with another framework

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Use Blocknative MCP with OpenAI Agents SDK

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Use Blocknative MCP with Claude Agent SDK

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Use Blocknative MCP with Claude Code

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Codex

Use Blocknative MCP with Codex

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OpenClaw

Use Blocknative MCP with OpenClaw

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CLI

Use Blocknative MCP with CLI

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Google ADK

Use Blocknative MCP with Google ADK

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LangChain

Use Blocknative MCP with LangChain

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Use Blocknative MCP with Vercel AI SDK

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Use Blocknative MCP with Mastra AI

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Use Blocknative MCP with LlamaIndex

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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 Hermes?

Yes, you can. Hermes 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
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Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

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