How to integrate Callback24 MCP with Hermes

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Api Key

Callback24 is a telephony API for managing phone calls, users, services, and routing groups. It centralizes call control and routing to automate voice workflows and operations.

27 Tools

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 Callback24 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.

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What is Composio Connect?

Composio Connect is a consumer offering that lets anyone plug 1,500+ 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 Callback24 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 Callback24

Ask your agent to connect to Callback24, or simply request any Callback24-related task. Hermes will prompt you to authenticate and authorize access.

4. Done. You're all set with a new Callback24 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 Callback24 or request any Callback24-related task. It will prompt you to authenticate and authorize access.

5. Done!

What is the Callback24 MCP server, and what's possible with it?

The Callback24 MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Callback24 account. It provides structured and secure access so your agent can perform Callback24 operations on your behalf.

Way Forward

With Callback24 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.

TOOLS

Supported Tools

Every Callback24 action and event your agent gets out of the box.

Assign User to Service

Assign a Callback24 user to a service, optionally within a routing group.

Batch Assign Users to Service

Sequentially assign 1-25 Callback24 users to one service.

Batch Remove Users from Service

Sequentially remove 1-25 users from a Callback24 service.

Cancel Upcoming Phone Calls

Irreversibly bulk-cancel every upcoming phone call matching a phone number or lead reference.

Create Group

Create a routing group within a Callback24 service, with optional localized names.

Create Phone Call

Create or schedule a real phone call in Callback24.

Create Service

Create a Callback24 service for a website.

Create User

Create a company user in Callback24.

Delete Group

Permanently and irreversibly delete one Callback24 routing group by group ID.

Delete Service

Permanently and irreversibly delete one Callback24 service and its associated routing and customer-facing widget configuration.

Delete User

Permanently and irreversibly delete one company user by Callback24 user ID.

Get Current User

Return the Callback24 user identity associated with the connected API token.

Get Group

Return one Callback24 routing group by ID with its service ID and localized names.

Get Phone Call

Return detailed metadata, tags, and assigned-user information for one Callback24 phone call.

Get Phone Call Recording

Return the recording URL for one recorded phone call.

Get Service

Return one Callback24 service with opening hours, routing groups, and assigned users.

Get User

Return one company user by Callback24 user ID.

List Groups

Return all Callback24 routing groups with their service IDs and localized names.

List Phone Calls

Return one page of phone-call history, optionally filtered by type, date range, phone number, users, or services.

List Services

Return all Callback24 services with their nested groups, assigned users, and opening hours.

List Users

Return all company users visible to the connected Callback24 account.

Remove User from Service

Remove a Callback24 user's assignment from a service, optionally within a routing group.

Update Group

Update one or more localized names for a Callback24 routing group.

Update Phone Call

Update editable metadata for an existing phone call without changing its explicit cancellation or start/end status fields.

Update Phone Call Status

Set a phone call's cancelled flag and/or recorded start and end times; this changes operational call state.

Update Service

Change the website configured for an existing Callback24 service.

Update User

Update one or more profile or role fields for an existing Callback24 company user.

FAQ

Frequently asked questions

With a standalone Callback24 MCP server, the agents and LLMs can only access a fixed set of Callback24 tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Callback24 and many other apps based on the task at hand, all through a single MCP endpoint.

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 Callback24 tools.

Yes, absolutely. You can configure which Callback24 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 Callback24 data and credentials are handled as safely as possible.

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