How to integrate Kit MCP with Codex

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Kit MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.

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Oauth2Api Key

Kit is a platform for creators and developers to automate tasks and publish apps on the Kit App Store. It helps streamline workflows so you can focus on what matters most.

42 Tools

Introduction

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Kit MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.

Also integrate Kit with

Why use Composio?

Apart from a managed and hosted MCP server, you will get:

  • CodeAct: A dedicated workbench that allows GPT to write its code to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
  • Large tool responses: Handle them to minimise context rot.
  • Dynamic just-in-time access to 20,000 tools across 1000+ other Apps for cross-app workflows. It loads the tools you need, so GPTs aren't overwhelmed by tools you don't need.

How to install Kit MCP in Codex

Run the setup command

Run this command in your terminal to add the Composio MCP server to Codex.

Terminal

It will initiate the authentication in a browser window, authorize Codex to access your Composio account.

Composio authentication page

(Optional) Authenticate with OAuth

To authenticate manually, run the login command to open a browser window and authorize Codex to access your Composio account.

bash
codex mcp login composio

Verify the connection

Run codex mcp list to confirm Composio appears as a registered MCP server.

bash
codex mcp list

Codex App

Codex App follows the same approach as VS Code.

  1. Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:
  2. Fill the header and Key fields with { "x-consumer-api-key" = "ck_*******" }.
  3. The Key is the Composio API key, that you can find on dashboard.composio.dev
  4. Click on Authenticate and authorize Codex to your Composio account and you're all set.
Codex App MCP setup
  1. Restart and verify if it's there in .codex/config.toml
bash
[mcp_servers.composio]
url = "https://connect.composio.dev/mcp"
http_headers = { "x-consumer-api-key" = "ck_*******" }

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

The Kit MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Kit account. It provides structured and secure access to your subscriber lists, tags, forms, and automations, so your agent can perform actions like managing subscribers, creating tags, updating custom fields, and handling broadcasts on your behalf.

  • Subscriber management and automation: Add new subscribers to forms, remove subscribers, or update their details to keep your audience lists accurate and engaged.
  • Custom field and tag creation: Automatically create, update, or delete custom fields and tags, making it easy to segment and personalize your communications.
  • Webhook and event setup: Set up or remove webhooks so your agent can listen for subscriber or purchase events and trigger automations as needed.
  • Broadcast and campaign control: Delete obsolete broadcasts or manage your messaging campaigns directly through your agent for streamlined outreach.
  • Account insights and configuration: Retrieve detailed account information, including plan details and primary contact, to keep your integrations and automations running smoothly.

Conclusion

You've successfully integrated Kit with Codex using Composio's MCP server. Now you can interact with Kit directly from your terminal, VS Code, or the Codex App using natural language commands.

Key benefits of this setup:

  • Seamless integration across CLI, VS Code, and standalone app
  • Natural language commands for Kit operations
  • Managed authentication through Composio
  • Access to 20,000+ tools across 1000+ apps for cross-app workflows
  • CodeAct workbench for complex tool chaining

Next steps:

  • Try asking Codex to perform various Kit operations
  • Explore cross-app workflows by connecting more toolkits
  • Build automation scripts that leverage Codex's AI capabilities
TOOLS

Supported Tools

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

Add Subscriber to Form

Add an existing subscriber to a form by their IDs.

Add Subscriber to Form by Email

Tool to add an existing subscriber to a form using their email address.

Create Broadcast

Tool to create a new broadcast (email campaign) to send to subscribers.

Create Custom Field

Tool to create a new custom field for subscriber data.

Create Subscriber

Tool to create a new subscriber or update an existing one (upsert).

Create Tag

Tool to create a new tag in the account.

Create Webhook

Creates a webhook subscription for real-time event notifications.

Delete Broadcast

Tool to delete a specific broadcast.

Delete Custom Field

Tool to delete a specific custom field.

Delete Subscriber

Unsubscribe a subscriber from all email communications by their ID.

Delete Tag

Tool to delete a tag by ID.

Delete Webhook

Tool to delete a webhook by ID.

Filter Subscribers

Tool to filter subscribers based on engagement criteria such as email opens, clicks, or delivery status.

Get Account

Tool to retrieve current account information.

Get Account Colors

Tool to retrieve list of colors associated with the account.

Get Broadcast

Tool to retrieve details of a specific broadcast by ID.

Get Broadcast Clicks

Tool to retrieve link click data for a specific broadcast by ID.

Get Broadcast Stats

Tool to retrieve statistics for a specific broadcast by ID.

Get Creator Profile

Tool to retrieve the creator profile information for the account.

Get Email Stats

Tool to retrieve email statistics for the account.

Get Growth Stats

Tool to retrieve growth statistics for the account over a date range.

Get Subscriber

Tool to retrieve a specific subscriber by their ID.

Get Subscriber Stats

Tool to retrieve email stats for a specific subscriber.

List Broadcasts

Tool to retrieve a paginated list of all broadcasts.

List Custom Fields

Tool to retrieve a paginated list of custom fields.

List Email Templates

Retrieve a paginated list of all email templates in the Kit account.

List Forms

Lists all forms in your Kit account with optional filtering and cursor-based pagination.

List Segments

Tool to retrieve a paginated list of segments.

List Sequences

Tool to retrieve a paginated list of all sequences.

List Subscribers

Tool to retrieve a list of subscribers.

List Subscribers For Form

Retrieves subscribers for a specific form by ID with optional filtering and cursor-based pagination.

List Tags

Retrieve a paginated list of all tags in the Kit account.

List Tag Subscribers

Tool to retrieve subscribers for a specific tag.

List Webhooks

Retrieve a paginated list of all webhooks configured in the Kit account.

Remove Tag From Subscriber

Tool to remove a tag from a subscriber using their subscriber ID.

Tag Subscriber

Tool to associate a subscriber with a specific tag by ID.

Tag Subscriber by Email

Assigns a tag to an existing subscriber using their email address.

Untag Subscriber by Email

Tool to remove a tag from a subscriber using their email address.

Update Account Colors

Tool to update the list of colors for the account.

Update Custom Field

Tool to update a custom field's label.

Update Subscriber

Tool to update an existing subscriber's information.

Update Tag

Tool to update a tag's name by ID.

FAQ

Frequently asked questions

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

Yes, you can. Codex 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 Kit tools.

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

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How to integrate Kit MCP with Codex | Composio