How to integrate Scheduleonce MCP with Codex

Framework Integration Gradient
Scheduleonce Logo
Codex Logo
divider

Introduction

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

Composio removes the Authentication handling completely from you. We handle the entire integration lifecycle, and all you need to do is just copy the URL below, authenticate inside Codex, and start using it.

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 870+ 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 Scheduleonce MCP in Codex

Codex CLI

Run the command in your terminal.

Terminal

This will auto-redirect you to the Rube authentication page.

Rube authentication redirect page

Once you're authenticated, you will be able to access the tools.

Verify the installation by running:

codex mcp list

If you otherwise prefer to use config.toml, add the following URL to it. You can get the bearer token from rube.app → Use Rube → MCP URL → Generate token

[projects."/home/user/composio"]
trust_level = "untrusted"

[mcp_servers.rube]
bearer_token_env_var = "your bearer token"
enabled = true
url = "https://rube.app/mcp"

Codex in VS Code

If you have installed Codex in VS Code.

Then: ⚙️ → MCP Settings → + Add servers → Streamable HTTP:

Add the Rube MCP URL: https://rube.app/mcp and the bearer token.

VS Code MCP Settings

To verify, click on the Open config.toml

Open config toml in Codex

Make sure it's there:

[mcp_servers.composio_rube]
bearer_token_env_var = "your bearer token"
enabled = true
url = "https://rube.app/mcp"

Codex App

Codex App follows the same approach as VS Code.

  1. Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:
Codex App MCP Settings
  1. Restart and verify if it's there in .codex/config.toml
[mcp_servers.composio_rube]
bearer_token_env_var = "your bearer token"
enabled = true
url = "https://rube.app/mcp"
  1. Save, restart the extension, and start working.

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

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

Supported Tools & Triggers

Tools
Book Time SlotTool to book a time slot on a booking calendar in OnceHub.
Cancel BookingTool to cancel a booking by ID in OnceHub.
Create ContactTool to create a new contact in ScheduleOnce.
Create One-Time Link for Booking CalendarTool to create a one-time booking link for a booking calendar in OnceHub.
Create UserTool to create a new user account in OnceHub.
Delete ContactTool to delete a contact by ID from OnceHub.
Delete UserTool to delete a user account from OnceHub.
Get Available Time SlotsTool to retrieve available time slots for a booking calendar from OnceHub.
Get Single BookingTool to retrieve a single booking by ID from OnceHub.
Get Single Booking CalendarTool to retrieve a single booking calendar by ID from OnceHub.
Get Single ContactTool to retrieve a single contact by ID from OnceHub.
Get Single Master PageTool to retrieve a single master page by ID from OnceHub.
Get Single UserTool to retrieve a single user by ID from OnceHub.
Get User Scheduling AvailabilityTool to get user scheduling availability from OnceHub.
List All Booking CalendarsTool to list all booking calendars in the account.
List All Booking PagesTool to list all booking pages in the account.
List All BookingsTool to list all bookings in the account.
List All ContactsTool to list all contacts in the OnceHub account.
List All Event TypesTool to list all event types in the account.
List All Master PagesTool to list all master pages in the account.
List All TeamsTool to list all teams in the OnceHub account.
List All UsersTool to list all users in the OnceHub account.
Mark Booking as No-ShowTool to mark a completed booking as no-show in OnceHub.
Test API KeyTool to validate API key authentication for OnceHub.
Update ContactTool to update an existing contact in ScheduleOnce.
Update UserTool to update an existing user in OnceHub.
Update User Scheduling AvailabilityTool to update user scheduling availability in OnceHub.

Conclusion

You've successfully integrated Scheduleonce with Codex using Composio's Rube MCP server. Now you can interact with Scheduleonce 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 Scheduleonce operations
  • Managed authentication through Composio's Rube
  • Access to 20,000+ tools across 870+ apps for cross-app workflows
  • CodeAct workbench for complex tool chaining

Next steps:

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

How to build Scheduleonce MCP Agent with another framework

FAQ

What are the differences in Tool Router MCP and Scheduleonce MCP?

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

Can I use Tool Router MCP with Codex?

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 Scheduleonce tools.

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

Yes, absolutely. You can configure which Scheduleonce 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.

How safe is my data with Composio Tool Router?

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 Scheduleonce data and credentials are handled as safely as possible.

Used by agents from

Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

Never worry about agent reliability

We handle tool reliability, observability, and security so you never have to second-guess an agent action.