How to integrate Circleci MCP with Pydantic AI

This guide walks you through connecting Circleci to Pydantic AI using the Composio tool router. By the end, you'll have a working Circleci agent that can trigger a new pipeline on main branch, list all pipelines for backend service, get test results from last successful build through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Circleci account through Composio's Circleci MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Api Key

Circleci is a leading continuous integration and delivery platform for automating code builds, tests, and deployments. It helps teams ship quality software faster by streamlining DevOps workflows.

65 Tools

Introduction

This guide walks you through connecting Circleci to Pydantic AI using the Composio tool router. By the end, you'll have a working Circleci agent that can trigger a new pipeline on main branch, list all pipelines for backend service, get test results from last successful build through natural language commands.

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

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

Also integrate Circleci with

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 Circleci
  • 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 Circleci 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 Circleci MCP server, and what's possible with it?

The Circleci MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Circleci account. It provides structured and secure access to your Circleci projects and pipelines, so your agent can trigger builds, fetch job artifacts, monitor workflows, and analyze test results on your behalf.

  • Automated pipeline triggering and management: Let your agent start new builds for specific branches or tags, enabling continuous integration workflows without manual intervention.
  • Workflow and job status monitoring: Ask your agent to fetch detailed information about jobs and workflows, including status, timing, and execution environment, to stay on top of your CI/CD processes.
  • Artifact and test result retrieval: Have the agent collect job artifacts or extract comprehensive test metadata and failure messages for easier debugging and reporting.
  • Pipeline and runner insights: Get your agent to list all pipelines for a project or enumerate available self-hosted runners, making it simple to manage and audit your Circleci resources.
  • User and configuration access: Retrieve user profile details or fetch pipeline YAML configurations as needed for documentation, troubleshooting, or workflow optimization.

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:

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

Step-by-step Guide

Step by step09 STEPS
1

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
2

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.
3

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 Circleci
  • pydantic-ai lets you create structured AI agents with tool support
  • python-dotenv loads your environment variables securely from a .env file
4

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
5

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 Circleci
  • MCPServerStreamableHTTP connects to the Circleci MCP server endpoint
  • Agent from Pydantic AI lets you define and run the AI assistant
6

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 Circleci
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["circleci"],
    )
    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 Circleci 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
7

Initialize the Pydantic AI Agent

python
# Attach the MCP server to a Pydantic AI Agent
circleci_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
agent = Agent(
    "openai:gpt-5",
    toolsets=[circleci_mcp],
    instructions=(
        "You are a Circleci assistant. Use Circleci tools to help users "
        "with their requests. Ask clarifying questions when needed."
    ),
)
What's happening:
  • The MCP client connects to the Circleci endpoint
  • The agent uses GPT-5 to interpret user commands and perform Circleci operations
  • The instructions field defines the agent's role and behavior
8

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 Circleci.\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
  • Circleci API calls happen automatically under the hood
  • The model keeps conversation history to maintain context across turns
9

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 Circleci 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 Circleci
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["circleci"],
    )
    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
    circleci_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
    agent = Agent(
        "openai:gpt-5",
        toolsets=[circleci_mcp],
        instructions=(
            "You are a Circleci assistant. Use Circleci 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 Circleci.\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 Circleci through Composio's Tool Router. With this setup, your agent can perform real Circleci 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 + Circleci 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 Circleci action and event your agent gets out of the box.

Create Context

Tool to create a new context in CircleCI.

Create Context (GraphQL)

Tool to create a new CircleCI context using the GraphQL API.

Create Context Restriction

Tool to create a context restriction in CircleCI.

Create Organization Orb Allowlist

Tool to create a new URL Orb allow-list entry for an organization.

Create Organization Project

Tool to create a new project within a CircleCI organization.

Create Organization Group

Tool to create a group in an organization.

Create Project Environment Variable

Tool to create a new environment variable for a CircleCI project.

Create Usage Export Job

Tool to create a usage export job for a CircleCI organization.

Delete Context (GraphQL)

Tool to delete a CircleCI context by its UUID using GraphQL API.

Delete Context Restriction

Tool to delete a context restriction by its ID.

Delete Namespace and Related Orbs

Tool to delete a CircleCI registry namespace and all its associated orbs.

Delete Namespace Alias

Tool to remove a namespace alias by name in CircleCI.

Delete Organization Orb Allowlist Entry

Tool to remove an entry from the organization's URL orb allow-list.

Delete Organization Group

Tool to delete a group from a CircleCI organization.

Delete Project

Tool to delete a CircleCI project and its settings.

Delete Project Environment Variable

Tool to delete an environment variable from a CircleCI project.

Get Context

Tool to retrieve a context by its unique ID.

Get Current User

Tool to retrieve information about the currently authenticated user.

Get Flaky Tests

Tool to get flaky tests for a project.

Get Job Artifacts

Retrieves artifacts (output files like test results, logs, build binaries, reports) produced by a CircleCI job.

Get Job Details

Tool to fetch details of a specific job within a project.

Get Orb Details

Tool to query detailed information about a CircleCI orb using the GraphQL API.

Get Orb Version

Tool to retrieve detailed information about a specific CircleCI orb version via GraphQL.

Get Organization

Tool to retrieve organization details from CircleCI using GraphQL query.

Get Organization Group

Tool to retrieve a group in an organization.

Get Pipeline Config

Tool to fetch pipeline configuration by ID.

Get Pipeline Definition

Tool to retrieve a pipeline definition by project and definition ID.

Get Project

Tool to retrieve a CircleCI project by its slug.

Get Project Workflows

Tool to get summary metrics for all workflows of a project.

Get Test Metadata

Tool to fetch test metadata for a specific job.

Get Usage Export Job

Tool to retrieve a usage export job by organization ID and job ID.

Get User Information

Tool to retrieve information about a CircleCI user by their unique ID.

Get Workflow Summary

Tool to get metrics and trends for a workflow.

List Context Environment Variables

Tool to list all environment variables for a specific context.

List Insights Branches

Tool to get all branches for a project from CircleCI Insights.

List Insights Summary

Tool to get summary metrics with trends for the entire organization and for each project.

List Namespace Orbs

Tool to list orbs in a CircleCI registry namespace with pagination support.

List Orb Categories

Tool to retrieve all CircleCI orb categories with pagination support.

List Orbs

Tool to list CircleCI orbs with pagination support via GraphQL API.

List Organization Groups

Tool to list all groups in a CircleCI organization.

List Pages Summary

Tool to get summary metrics and trends for a project across its workflows and branches.

List Pipeline Definitions

Tool to list all pipeline definitions for a specific project.

List Pipelines

Tool to get a list of pipelines for an organization.

List Pipelines for Project

Tool to list all pipelines for a specific project.

List Project Environment Variables

Tool to list all environment variables for a CircleCI project.

List Project Schedules

Tool to list all schedules for a specific project.

List Self-Hosted Runners

List self-hosted runners in CircleCI.

List User Collaborations

Tool to retrieve organizations where the authenticated user has access.

List Workflows by Pipeline ID

Tool to list all workflows associated with a specific pipeline.

List Workflows Jobs Workflows

Tool to get summary metrics for a project workflow's jobs.

List Workflows Test Metrics

Tool to get test metrics for a project's workflows.

Query Context

Tool to retrieve a CircleCI context by its UUID using GraphQL API.

Query Namespace Exists

Tool to determine if a namespace exists in the CircleCI registry.

Query Orb Category ID

Tool to fetch the unique category ID for a CircleCI orb category by its name.

Query Orb Exists

Tool to check if an orb exists in CircleCI registry and retrieve its privacy status.

Query Orb ID

Tool to fetch an orb's ID and optionally its namespace ID by orb name.

Query Orb Latest Version

Tool to fetch the latest published version of a CircleCI orb.

Query Orb Source

Tool to retrieve source code of a specific CircleCI orb version via GraphQL.

Query Plan Metrics

Tool to query plan metrics including credit usage by project and organization for a date range.

Remove Context Environment Variable (GraphQL)

Tool to remove an environment variable from a CircleCI context using GraphQL API.

Rename Namespace

Tool to rename a CircleCI namespace by its UUID identifier.

Store Environment Variable

Tool to store an environment variable in a CircleCI context using GraphQL mutation.

Trigger Pipeline

Triggers a new CI/CD pipeline run for a specified CircleCI project.

Upsert Context Environment Variable

Tool to add or update an environment variable in a CircleCI context.

Validate Orb Config

Tool to validate CircleCI orb YAML configuration using the orbConfig GraphQL query.

FAQ

Frequently asked questions

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

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

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