How to integrate Callback24 MCP with Atomic Agent

Connect Atomic Agent to Callback24 MCP. Place an outbound call to +15551234 now, create voicemail transcription for latest call, and more using natural language, with authentication handled for you.

Callback24 logoCallback24
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

Atomic Agent is an open-source AI agent that runs on your machine and supports local models through llama.cpp. Connect it to 1,500+ apps through Composio, including Callback24.

This guide uses Atomic Agent's built-in Composio integration. You need Atomic Agent v0.5.6 or later, your own Composio API key, and a Callback24 account. See the Atomic Agent documentation for installation instructions.

Also integrate Callback24 with

How Atomic Agent connects to Callback24

Atomic Agent connects to Composio's Tool Router over Streamable HTTP MCP. It discovers the tools needed for your request, and Composio handles account authentication.

Execution and account-connection tools follow Atomic Agent's configured approval policy. Review any approval prompt before allowing an action on your connected account.

Connect Callback24 to Atomic Agent

  1. Sign up or sign in to the Composio dashboard. Copy your API key.
  2. In Atomic Agent, open the Integrations tab and select Composio. Select API key, press e, paste the key, and press Enter. The tools become available immediately, without a restart.
  3. Ask Atomic Agent to do something in Callback24. It searches Composio for the right tool.
  4. On first use, open the sign-in link returned in the chat. Connect your Callback24 account, then return to Atomic Agent to continue.

Headless setup

Add the following line to ~/.atomic-agent/.env, replacing YOUR_COMPOSIO_API_KEY with your key. Start Atomic Agent after saving the file.

bash
COMPOSIO_API_KEY=YOUR_COMPOSIO_API_KEY

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.

Use Callback24 from Atomic Agent

With your account connected, ask Atomic Agent to work with Callback24 in natural language. You can connect more apps through the same Composio integration as you need them.

Visit the Atomic Agent website or inspect the Atomic Agent source code.

Troubleshooting

Why is my API key rejected?

Copy the key directly from the Composio dashboard. Atomic Agent requires ASCII characters because it sends the key in an HTTP header. Remove any extra characters introduced when copying.

Why are Composio tools unavailable after saving a key?

Check that you use Atomic Agent v0.5.6 or later and that Composio is enabled in your configuration. A "composio": { "enabled": false } setting disables the integration while keeping the saved key on disk.

Does Composio have a free plan?

The Hobby plan includes 100,000 tool calls per month. Composio-managed OAuth apps have a lower included allowance. See Composio pricing for the current limits that apply to your connection.

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. Atomic Agent 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.

Start with Callback24.It takes 30 seconds.

Managed auth, hosted MCP servers, and every Callback24 tool your agent needs.Free to start.

Start building