How to integrate Postgrid 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 Postgrid 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 Postgrid 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 Postgrid 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 Postgrid

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

4. Done. You're all set with a new Postgrid 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 Postgrid or request any Postgrid-related task. It will prompt you to authenticate and authorize access.

5. Done!

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

The Postgrid MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Postgrid account. It provides structured and secure access to your direct mail and address automation tools, so your agent can verify addresses, send letters, manage contacts, and handle templates for your business communications—all without manual intervention.

  • Automated letter sending: Have your agent create and send physical letters on demand, handling recipient, sender, and content details seamlessly.
  • Contact management: Effortlessly add, update, or delete contacts in your Postgrid account to keep your mailing lists accurate and up to date.
  • Template creation and maintenance: Let your agent generate reusable mail templates with dynamic placeholders, and remove outdated templates as needed.
  • Bank account and payment management: Create or delete bank accounts associated with print and mail services, ensuring smooth financial operations for mail automation.
  • Webhook setup and monitoring: Enable your agent to create or remove webhooks to track events and receive real-time notifications for your mail orders and services.

Supported Tools & Triggers

Tools
CREATE_BANK_ACCOUNTTool to create a new bank account for print & mail service.
Create ContactTool to create a new contact in postgrid.
Create LetterTool to create and send a letter via postgrid.
Create TemplateTool to create a new mail template in postgrid.
Create WebhookTool to create a new webhook to receive order event notifications.
Delete Bank AccountTool to delete a bank account by its id.
Delete ContactTool to delete a contact by its id.
Delete TemplateTool to delete a template by its id.
Delete WebhookTool to delete a webhook subscription.
Get Bank AccountTool to retrieve a bank account.
Get ContactTool to retrieve a contact.
Get LetterTool to retrieve a letter.
Get TemplateTool to retrieve a template.
Get WebhookTool to retrieve details of a specific webhook by its id.
List Bank AccountsTool to list bank accounts.
List ChequesTool to list cheques with optional filters and pagination.
List ContactsTool to list contacts.
List LettersTool to list letters.
List PostcardsTool to retrieve a list of postcards with optional filtering and pagination.
List Self-MailersTool to list self-mailers.
List TemplatesTool to list templates.
List WebhooksTool to retrieve a list of configured webhooks with optional filtering and pagination.

Way Forward

With Postgrid 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 Postgrid MCP Agent with another framework

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Claude Agent SDK

Use Postgrid MCP with Claude Agent SDK

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Claude Code

Use Postgrid MCP with Claude Code

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Codex

Use Postgrid MCP with Codex

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OpenClaw

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CLI

Use Postgrid MCP with CLI

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Use Postgrid MCP with Google ADK

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LangChain

Use Postgrid MCP with LangChain

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Use Postgrid MCP with Vercel AI SDK

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Use Postgrid MCP with Mastra AI

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Use Postgrid MCP with LlamaIndex

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CrewAI

Use Postgrid MCP with CrewAI

FAQ

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

With a standalone Postgrid MCP server, the agents and LLMs can only access a fixed set of Postgrid tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Postgrid 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 Postgrid tools.

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

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

Used by agents from

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