How to integrate Etermin MCP with Pydantic AI

This guide walks you through connecting Etermin to Pydantic AI using the Composio tool router. By the end, you'll have a working Etermin agent that can add new client contact for booking, remove canceled appointment from calendar, create voucher for returning customer through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Etermin account through Composio's Etermin MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Etermin

Api Key

eTermin is an online appointment scheduling platform for businesses to manage bookings. It streamlines client appointments, saving time and reducing scheduling conflicts.

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Introduction

This guide will help you understand how to give your Pydantic AI agent real control over a Etermin account through Composio's Etermin MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate Etermin with

OpenAI Agents SDK Claude Agent SDK Claude Code Claude Cowork Codex OpenClaw Hermes CLI Google ADK LangChain Vercel AI SDK Mastra AI LlamaIndex CrewAI

TL;DR

Here's what you'll learn:

How to set up your Composio API key and User ID
How to create a Composio Tool Router session for Etermin
How to attach an MCP Server to a Pydantic AI agent
How to stream responses and maintain chat history
How to build a simple REPL-style chat interface to test your Etermin workflows

What is Pydantic AI?

Pydantic AI is a Python framework for building AI agents with strong typing and validation. It leverages Pydantic's data validation capabilities to create robust, type-safe AI applications.

Key features include:

Type Safety: Built on Pydantic for automatic data validation
MCP Support: Native support for Model Context Protocol servers
Streaming: Built-in support for streaming responses
Async First: Designed for async/await patterns

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

The Etermin MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Etermin account. It provides structured and secure access to your appointment scheduling system, so your agent can perform actions like creating contacts, managing bookings, updating resources, and handling calendar events on your behalf.

Automated contact and user creation: Instantly add new clients or team members to your Etermin account, streamlining onboarding and customer management.
Effortless appointment and calendar management: Let your agent delete existing appointments or calendars, freeing up schedules and reducing manual work.
Resource and service administration: Automatically create or remove resources and services, ensuring your booking system stays current as your business evolves.
Voucher and webhook setup: Quickly generate new vouchers for promotions or set up webhooks for real-time event notifications and integrations.
Contact and service deletion: Easily remove outdated contacts or services, keeping your scheduling platform organized and clutter-free.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS

Prerequisites

Before starting, make sure you have:

Python 3.9 or higher
A Composio account with an active API key
Basic familiarity with Python and async programming

Getting API Keys for OpenAI and Composio

OpenAI API Key

Go to the OpenAI dashboard and create an API key. You'll need credits to use the models, or you can connect to another model provider.
Keep the API key safe.

Composio API Key

Log in to the Composio dashboard.
Navigate to your API settings and generate a new API key.
Store this key securely as you'll need it for authentication.

Install dependencies

bash

pip install composio pydantic-ai python-dotenv

Install the required libraries.

What's happening:

composio connects your agent to external SaaS tools like Etermin
pydantic-ai lets you create structured AI agents with tool support
python-dotenv loads your environment variables securely from a .env file

Set up environment variables

bash

COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here
OPENAI_API_KEY=your_openai_api_key

Create a .env file in your project root.

What's happening:

COMPOSIO_API_KEY authenticates your agent to Composio's API
USER_ID associates your session with your account for secure tool access
OPENAI_API_KEY to access OpenAI LLMs

Import dependencies

python

import asyncio
import os
from dotenv import load_dotenv
from composio import Composio
from pydantic_ai import Agent
from pydantic_ai.mcp import MCPServerStreamableHTTP

load_dotenv()

What's happening:

We load environment variables and import required modules
Composio manages connections to Etermin
MCPServerStreamableHTTP connects to the Etermin MCP server endpoint
Agent from Pydantic AI lets you define and run the AI assistant

Create a Tool Router Session

python

async def main():
    api_key = os.getenv("COMPOSIO_API_KEY")
    user_id = os.getenv("USER_ID")
    if not api_key or not user_id:
        raise RuntimeError("Set COMPOSIO_API_KEY and USER_ID in your environment")

    # Create a Composio Tool Router session for Etermin
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["etermin"],
    )
    url = session.mcp.url
    if not url:
        raise ValueError("Composio session did not return an MCP URL")

What's happening:

We're creating a Tool Router session that gives your agent access to Etermin tools
The create method takes the user ID and specifies which toolkits should be available
The returned session.mcp.url is the MCP server URL that your agent will use

Initialize the Pydantic AI Agent

python

# Attach the MCP server to a Pydantic AI Agent
etermin_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
agent = Agent(
    "openai:gpt-5",
    toolsets=[etermin_mcp],
    instructions=(
        "You are a Etermin assistant. Use Etermin tools to help users "
        "with their requests. Ask clarifying questions when needed."
    ),
)

What's happening:

The MCP client connects to the Etermin endpoint
The agent uses GPT-5 to interpret user commands and perform Etermin operations
The instructions field defines the agent's role and behavior

Build the chat interface

python

# Simple REPL with message history
history = []
print("Chat started! Type 'exit' or 'quit' to end.\n")
print("Try asking the agent to help you with Etermin.\n")

while True:
    user_input = input("You: ").strip()
    if user_input.lower() in {"exit", "quit", "bye"}:
        print("\nGoodbye!")
        break
    if not user_input:
        continue

    print("\nAgent is thinking...\n", flush=True)

    async with agent.run_stream(user_input, message_history=history) as stream_result:
        collected_text = ""
        async for chunk in stream_result.stream_output():
            text_piece = None
            if isinstance(chunk, str):
                text_piece = chunk
            elif hasattr(chunk, "delta") and isinstance(chunk.delta, str):
                text_piece = chunk.delta
            elif hasattr(chunk, "text"):
                text_piece = chunk.text
            if text_piece:
                collected_text += text_piece
        result = stream_result

    print(f"Agent: {collected_text}\n")
    history = result.all_messages()

What's happening:

The agent reads input from the terminal and streams its response
Etermin API calls happen automatically under the hood
The model keeps conversation history to maintain context across turns

Run the application

python

if __name__ == "__main__":
    asyncio.run(main())

What's happening:

The asyncio loop launches the agent and keeps it running until you exit

Complete Code

Here's the complete code to get you started with Etermin and Pydantic AI:

python

import asyncio
import os
from dotenv import load_dotenv
from composio import Composio
from pydantic_ai import Agent
from pydantic_ai.mcp import MCPServerStreamableHTTP

load_dotenv()

async def main():
    api_key = os.getenv("COMPOSIO_API_KEY")
    user_id = os.getenv("USER_ID")
    if not api_key or not user_id:
        raise RuntimeError("Set COMPOSIO_API_KEY and USER_ID in your environment")

    # Create a Composio Tool Router session for Etermin
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["etermin"],
    )
    url = session.mcp.url
    if not url:
        raise ValueError("Composio session did not return an MCP URL")

    # Attach the MCP server to a Pydantic AI Agent
    etermin_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
    agent = Agent(
        "openai:gpt-5",
        toolsets=[etermin_mcp],
        instructions=(
            "You are a Etermin assistant. Use Etermin tools to help users "
            "with their requests. Ask clarifying questions when needed."
        ),
    )

    # Simple REPL with message history
    history = []
    print("Chat started! Type 'exit' or 'quit' to end.\n")
    print("Try asking the agent to help you with Etermin.\n")

    while True:
        user_input = input("You: ").strip()
        if user_input.lower() in {"exit", "quit", "bye"}:
            print("\nGoodbye!")
            break
        if not user_input:
            continue

        print("\nAgent is thinking...\n", flush=True)

        async with agent.run_stream(user_input, message_history=history) as stream_result:
            collected_text = ""
            async for chunk in stream_result.stream_output():
                text_piece = None
                if isinstance(chunk, str):
                    text_piece = chunk
                elif hasattr(chunk, "delta") and isinstance(chunk.delta, str):
                    text_piece = chunk.delta
                elif hasattr(chunk, "text"):
                    text_piece = chunk.text
                if text_piece:
                    collected_text += text_piece
            result = stream_result

        print(f"Agent: {collected_text}\n")
        history = result.all_messages()

if __name__ == "__main__":
    asyncio.run(main())

Conclusion

You've built a Pydantic AI agent that can interact with Etermin through Composio's Tool Router. With this setup, your agent can perform real Etermin actions through natural language. You can extend this further by:

Adding other toolkits like Gmail, HubSpot, or Salesforce
Building a web-based chat interface around this agent
Using multiple MCP endpoints to enable cross-app workflows (for example, Gmail + Etermin for workflow automation)

This architecture makes your AI agent "agent-native", able to securely use APIs in a unified, composable way without custom integrations.

TOOLS

Supported Tools

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

Assign Calendar Service

Tool to assign a service to a calendar in eTermin.

Create Absence

Tool to create an absence (non-working time) for a specific calendar.

Create Anchortime

Tool to create anchortimes (recurring time slots) in a calendar.

Create Anchortime by Date

Tool to create anchortimes by date.

Create Appointment

Tool to create a new appointment in eTermin.

Create Appointment via Sync

Tool to create an appointment via sync in eTermin.

Create Calendar Return Time

Tool to create a return time for a calendar.

Create Contact

Tool to create a new contact in eTermin.

Create Service

Tool to create a new service in eTermin.

Create Service Group

Tool to create a new service group in eTermin.

Create User

Tool to create a new user.

Create Usermapping

Tool to create a new usermapping in eTermin.

Create Voucher

Creates a new discount voucher in eTermin.

Create Webhook

Creates a webhook (web push notification) in eTermin to receive real-time updates about appointments.

Create Working Time

Tool to create a new working time slot in eTermin.

Create Working Times Date

Tool to create a working times date slot for a calendar.

Delete Absence

Tool to delete an absence (non-working time) from a calendar.

Delete Anchortime

Delete an anchortime from eTermin by its ID.

Delete Anchortime By Date

Delete an anchortime by date using its ID.

Delete Appointment

Delete an existing appointment by its ID.

Delete Appointment via Sync

Tool to delete appointments via the sync endpoint.

Delete Calendar

Delete a calendar from your eTermin account.

Delete Calendar Return Time

Delete a return time from a calendar.

Delete Calendar Service

Delete an assigned service from a calendar in eTermin.

Delete Contact

Delete a contact from your eTermin account by its contact ID.

Delete Resource

Delete an eTermin resource by type and ID.

Delete Service

Permanently deletes a service from your eTermin account by its ID.

Delete Service Group

Delete a service group from your eTermin account by its ID.

Delete User

Deletes an existing user from the eTermin account.

Delete Usermapping

Delete a usermapping by its ID.

Delete Voucher

Permanently deletes a voucher from eTermin by its voucher code.

Delete Webhook

Delete an existing webhook by its unique identifier.

Delete Working Times

Tool to delete working times from a calendar.

Delete Working Times Date

Tool to delete working times date entries from eTermin.

Get Absences

Tool to retrieve absences (non-working times) for a specific calendar.

Get Anchortime by Date

Tool to retrieve anchortimes by date.

Get Anchortimes

Tool to retrieve anchortime details.

Get Appointment Sync

Tool to synchronize appointments incrementally from eTermin.

Get Bookingpage Logs

Tool to retrieve bookingpage request logs from eTermin.

Get Calendar Return Time

Tool to retrieve return times for a specific calendar.

Get Calendars

Tool to retrieve calendars.

Get Calendar Service Assignments

Tool to retrieve calendar service assignments.

Get Company

Tool to retrieve company account details.

Get Contact By ID

Tool to retrieve a specific contact by ID, external ID, or email.

Get Contacts

Tool to retrieve a list of contacts.

Get Deleted Appointments

Tool to retrieve a list of deleted appointments from eTermin.

Get Message Logs

Tool to retrieve message logs from eTermin.

Get Customer Ratings

Tool to retrieve a list of customer ratings from eTermin.

Get Service By ID

Tool to retrieve a specific service from eTermin.

Get Service Calendar

Tool to retrieve calendars for a specific service ID.

Get Service Group

Tool to retrieve service group details from eTermin.

Get Services

Tool to retrieve a list of services.

Get Survey Results

Tool to retrieve survey results from eTermin.

Get Timeslots

Tool to retrieve available timeslots for a specific calendar on a given date.

Get Usermapping

Tool to retrieve usermapping information.

Get Users

Tool to retrieve a list of users.

Get Working Times

Tool to retrieve working times for a specific calendar.

Get Working Times Date

Tool to retrieve working times for a specific calendar on a specific date.

List Appointments

Tool to retrieve a filtered list of appointments from eTermin in a specified date range.

List Vouchers

Retrieve all vouchers (discount codes) from your eTermin account.

List Webhooks

Tool to retrieve webhooks.

Update Service via PUT

Tool to update a service in eTermin.

Update Absence

Tool to update an absence (non-working time) for a calendar in eTermin.

Update Anchortime

Update an existing anchortime in eTermin.

Update Anchortime By Date

Tool to update anchortimes by date in eTermin.

Update Appointment

Tool to update an existing appointment in eTermin.

Update Calendar

Update an existing calendar in eTermin.

Update Calendar Return Time

Tool to update a return time for a calendar in eTermin.

Update Contact

Tool to update an existing contact in eTermin.

Update Resource

Update an existing eTermin resource (contact, service, calendar, user, or voucher).

Update Service

Tool to update an existing service.

Update Service Group

Tool to update an existing service group in eTermin.

Update Synchronised Appointment

Tool to update a synchronised appointment in eTermin.

Update Usermapping

Update an existing usermapping in eTermin.

Update Voucher

Updates an existing voucher in eTermin.

Update Webhook

Update an existing webhook configuration in eTermin.

Update Working Times

Tool to update working times for a calendar in eTermin.

Update Working Times Date

Tool to update working times date for a calendar.

FRAMEWORKS

How to build Etermin MCP Agent with another framework

OpenAI Agents SDK

Use Etermin MCP with OpenAI Agents SDK

Claude Agent SDK

Use Etermin MCP with Claude Agent SDK

Claude Code

Use Etermin MCP with Claude Code

Claude Cowork

Use Etermin MCP with Claude Cowork

Codex

Use Etermin MCP with Codex

OpenClaw

Use Etermin MCP with OpenClaw

Hermes

Use Etermin MCP with Hermes

CLI

Use Etermin MCP with CLI

Google ADK

Use Etermin MCP with Google ADK

LangChain

Use Etermin MCP with LangChain

Vercel AI SDK

Use Etermin MCP with Vercel AI SDK

Mastra AI

Use Etermin MCP with Mastra AI

LlamaIndex

Use Etermin MCP with LlamaIndex

CrewAI

Use Etermin MCP with CrewAI

MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

Google Calendar

Oauth2

Google Calendar is a time management service for scheduling meetings, events, and reminders. It streamlines personal and team organization with integrated notifications and sharing options.

Apaleo

Oauth2

Apaleo is a cloud-based property management platform for hospitality businesses. It centralizes reservations, billing, and daily operations for smoother hotel management.

Appointo

Api Key

Appointo is an appointment booking platform for Shopify stores. It lets businesses add online scheduling to their websites with zero coding.

Bart

Api Key

Bart is the Bay Area Rapid Transit system, providing fast public transportation across the San Francisco Bay Area. It helps commuters and travelers get real-time schedule info, plan routes, and stay updated on service changes.

FAQ

Frequently asked questions

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

Yes, you can. Pydantic AI 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 Etermin tools.

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

Start with Etermin.It takes 30 seconds.

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

Start building

Customer stories

Teams ship real agents on Composio

GET STARTED FOR FREE BOOK A DEMO

Karan skipped his own birthday party to fix our critical issue. It was 10pm and he diverted his Waymo to help us instead. This really sets the bar — it shows the commitment you need when users rely on your software.

Harsha Gaddipati

Co-founder, Slashy

A lot of students tell us that the moment their connected tools start talking to each other inside Opennote feels almost magical. The agent just knows them, and it's immensely helped keep new users on the platform.

Abhi Arya

Co-founder, Opennote

We chose Composio over Pipedream because it delivered depth where it mattered — niche tools and tricky edge cases other platforms simply ignored. That gave us confidence to scale without compromising.

Nirman Dave

CEO, Zams

As a solo builder, shipping fast is life or death. The only way I can outcompete incumbents is by outmanoeuvring them. Getting bogged down managing agent auth would have been a death sentence.

Ryan Yu

Founder, Extra Thursday

Before Composio, adding tool integrations was slow and resource-intensive. Each one could take weeks of engineering time, and maintaining them meant constantly keeping up with API changes.

Tomisin Jenrola

Founder & CEO, SwarmZero

With hands-on help from their founder, we integrated Gmail and Google Drive in just 30 minutes. This level of personal support and commitment is exactly what startups should strive for.

Jerome Leclanche

Co-Founder, Ingram Technologies

How to integrate Etermin MCP with Pydantic AI

Connect Etermin without auth hassles

Introduction

Also integrate Etermin with

TL;DR

What is Pydantic AI?

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

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

How the Composio SDK works

Step-by-step Guide

Prerequisites

Getting API Keys for OpenAI and Composio

Install dependencies

Set up environment variables

Import dependencies

Create a Tool Router Session

Initialize the Pydantic AI Agent

Build the chat interface

Run the application

Complete Code

Conclusion

Supported Tools

How to build Etermin MCP Agent with another framework

OpenAI Agents SDK

Claude Agent SDK

Claude Code

Claude Cowork

Codex

OpenClaw

Hermes

CLI

Google ADK

LangChain

Vercel AI SDK

Mastra AI

LlamaIndex

CrewAI

Explore Other Toolkits

Google Calendar

Apaleo

Appointo

Bart

Frequently asked questions

What are the differences in Tool Router MCP and Etermin MCP?+

Can I use Tool Router MCP with Pydantic AI?+

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

How safe is my data with Composio Tool Router?+

Start with Etermin.It takes 30 seconds.

Teams ship real agents on Composio