How to integrate Taxjar 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 Taxjar 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 Taxjar 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 Taxjar 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 Taxjar

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

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

5. Done!

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

The Taxjar MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Taxjar account. It provides structured and secure access to your sales tax data, so your agent can perform actions like calculating sales tax, managing transactions, listing customers, and monitoring nexus regions on your behalf.

  • Real-time tax calculation for orders: Instantly calculate accurate sales tax for new orders, factoring in nexus addresses, line items, shipping, and exemptions.
  • Order and refund transaction management: Let your agent create, list, or delete order and refund transactions to streamline your sales and returns workflow.
  • Customer database access: Effortlessly retrieve, list, or delete customer records for tax reporting and compliance purposes.
  • Nexus region insights: Quickly identify and list all nexus regions where your business has sales tax obligations.
  • Automated transaction reporting: Access up-to-date lists of transactions and refunds for reconciliation, filing, and audit readiness.

Supported Tools & Triggers

Tools
Calculate Sales Tax For An OrderTool to calculate sales tax for an order.
Create Order TransactionTool to create a new order transaction.
Create Refund TransactionTool to create a new refund transaction.
Delete CustomerTool to delete an existing customer.
Delete Order TransactionTool to delete an existing order transaction.
Delete Refund TransactionTool to delete an existing refund transaction.
List CustomersTool to list existing customers.
List Nexus RegionsTool to list existing nexus regions for an account.
List Order TransactionsTool to list existing order transactions.
List refund transactionsTool to list refund transactions.
List Tax CategoriesTool to list all product tax categories and their codes.
Show CustomerTool to show an existing customer.
Show Order TransactionTool to show an existing order transaction by id.
Show Refund TransactionTool to show a refund transaction.
Show Tax Rates for a LocationTool to show sales tax rates for a location.
Summarize Tax Rates for All RegionsTool to retrieve minimum and average sales tax rates by region.
Update Order TransactionTool to update an existing order transaction.
Validate VAT NumberTool to validate a vat number for tax-exempt status.

Way Forward

With Taxjar 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 Taxjar MCP Agent with another framework

FAQ

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

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

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

Yes, absolutely. You can configure which Taxjar 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 Taxjar 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.