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Connect Codex to Cal.com

Connect Codex to Cal.com in 3 steps: 1. Sign in to ApexGenius and connect Cal.com. 2. Add the ApexGenius plugin. 3. Start using Cal.com in Codex. Start in Plugins in the ChatGPT desktop app and authorize your connection.

Connect Cal.comSee the setup

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How to connect Cal.com to Codex

  1. 1Sign in to ApexGenius and connect Cal.com
  2. 2Add the ApexGenius plugin to Codex
  3. 3Start using Cal.com in Codex

FirstConnect Cal.com to ApexGenius

ThenConnect ApexGenius to Codex

Cal.comapp.cal.com/settings/developer/api-keys1 of 3

Connect Cal.com. Create an API key in Cal.com. You paste it into ApexGenius once.

Then ask Codex:

List my upcoming Cal.com bookings for this week. Do not book, move or cancel anything.

Written setup, step by stepShow

Before you start

  • A Cal.com account.
  • An API key from Cal.com Settings > Developer > API keys.

1. Connect Cal.com to ApexGenius

  1. Create an API key in Cal.com. In Cal.com open Settings, then Developer, then API keys, and choose New. Name the key, turn on Never expires, and choose Create. Copy the key once. Without Never expires it stops working after 30 days.
    The full Cal.com settings page on Developer, API keys, with the account name blurred and red boxes marking the API keys menu item and the New button.
    Settings, then Developer, then API keys. New, marked in red, starts a key for your own account. The account name is blurred in this capture.Open full-size image (opens in a new tab)
    The full Cal.com Create an API key dialog with red boxes marking the Never expires switch and the Create button, and the account name blurred.
    Name the key, turn on Never expires, and choose Create. A key left on the 30-day default stops working after a month.Open full-size image (opens in a new tab)
  2. Open Cal.com in Connections. Choose Connect or Add connection.
  3. Enter the API key. Paste the key from Cal.com. ApexGenius supplies the API address and checks the key against your Cal.com profile.
  4. Check the saved connection. Save after validation succeeds. Review the Tools tab. Booking, rescheduling and cancelling email the attendees.
Connect Cal.com →

2. Connect ApexGenius to Codex

  1. In the desktop app, open Settings, then MCP servers and Add server.
  2. Name the server ApexGenius, choose Streamable HTTP, and paste the MCP address above.
  3. Save, then select Restart. Choose Authenticate for ApexGenius and complete the browser sign-in.
  4. When ApexGenius asks what this AI client may use, choose Read only for the first test, or Custom to limit it to the tools you need.
  5. Start a new conversation and select ApexGenius from the available tools before asking for live data.
Official Codex setup instructions ↗

Watch the setup

Follow each step at your own pace.

Codex desktop app with Plugins selected and ApexGenius listed under Available to your account.
Open Codex in the ChatGPT desktop app, then Plugins, and find ApexGenius.Open full-size image (opens in a new tab)

Step 1 of 4Open Plugins

The walkthrough uses the original ChatGPT web plugin captures. After connecting, open Codex in the desktop app and start a new task with ApexGenius. A ChatGPT web connection does not verify Codex access.

A public ApexGenius plugin listing is not verified. Use a plugin shared with you or one you created, subject to your account and workspace policy.

OpenAI Plugins guide (opens in a new tab)Full Codex setup guide
Create a personal plugin

Where Developer mode is available, open ChatGPT Settings, then Security and login, and enable it. In Plugins, select the plus button, enter ApexGenius and a description, then add this URL under Connection. Create the connection, complete OAuth, and review the tools. Return to Codex in the desktop app and start a new task with the plugin enabled.

https://server.autom8.pro/mcp
OpenAI custom connection guide (opens in a new tab)
No plugin available? Use desktop settings
  1. In the ChatGPT desktop app, open Settings, then MCP servers, then Add server.
  2. Name the server ApexGenius, choose Streamable HTTP, and paste the MCP address below.
  3. Save, select Restart, then Authenticate. Sign in to ApexGenius and authorize the intended connections and access.
  4. Start a new Codex task and ask one read-only question. Check the returned result and its matching successful read in Activity.
https://server.autom8.pro/mcp
OpenAI desktop MCP settings (opens in a new tab)
Manual setup for developers

Codex CLI is optional. Run these commands, complete browser authorization, then start a new session. Do not paste bearer tokens or static authorization headers.

Register the remote MCP server

codex mcp add apexgenius --url https://server.autom8.pro/mcp

Authorize in your browser

codex mcp login apexgenius

Inspect registered servers

codex mcp list

The desktop app, CLI, and IDE extension share MCP configuration on the same host. The IDE extension does not install plugins. ChatGPT web does not read local Codex configuration.

3. Verify one safe read

List my upcoming Cal.com bookings for this week. Do not book, move or cancel anything.

List my upcoming Cal.com bookings for this week. Do not book, move or cancel anything.

Compare the bookings with your Cal.com Upcoming list. Reading bookings sends no emails.

What Codex can do in Cal.com

3 operations. Read looks things up and changes nothing. Write changes Cal.com and runs only when that tool is enabled.

Read2 operations

Looks things up. Changes nothing.
  • cal_com_search_operationsDiscover the Cal.com operations reviewed and exposed by ApexGenius.
  • cal_com_read_operationRead your profile, event types, bookings, schedules and open time slots.

Write1 operation

Changes Cal.com. Runs only when enabled.
  • cal_com_write_operationBook, reschedule or cancel a meeting. Each one emails the attendees.

You choose what Codex can use

When you approve Codex, pick Full access, Read only, or Custom. Read only allows the Read operations and nothing else. Custom picks apps and tools one by one.

Limits in Cal.com

  • · The API key covers its Cal.com account. Requests use the fixed Cal.com API address.
  • · The read route refuses booking changes. Enabled writes run when called.
  • · Booking, rescheduling and cancelling email attendees. Cancelling a meeting cannot restore the original booking.

What it looks like in Codex

An illustrative read-only request and response. Your results come from the account and dates you choose.

How the route works
Codex
CodexApexGenius MCP route
List my upcoming Cal.com bookings for this week. Do not book, move or cancel anything.
ApexGenius
Working with ApexGenius3 reads
RequestConnected read
Account scopeAuthorized connections checked
Salesforceapex_call_read_toolsalesforce_read · Find matching recordsComplete
Salesforceapex_call_read_toolsalesforce_read · Read related activityComplete
n8napex_call_read_tooln8n_get_workflow · Check workflow statusComplete
Codex

Three safe example reads returned results. Nothing was changed.

Read-only route
Codex

Try asking

“List my upcoming Cal.com bookings for this week. Do not book, move or cancel anything.”

“Show my Cal.com event types and their available time slots. Do not create a booking.”

More connections like this one

One ApexGenius account covers every pair below. Connect an app once and each agent you allow can use it.

Questions people ask first

What do I need to connect Cal.com?

A Cal.com account and an API key from Settings, Developer, API keys. ApexGenius checks it against your profile before saving.

Can my AI send booking emails?

Booking, rescheduling and cancelling through an enabled write tool email attendees. Start with reads and enable booking tools only when needed.

Does this use Cal.com hosted MCP?

ApexGenius uses the official Cal.com API v2 with your API key.

What should I test first?

Ask for your upcoming bookings and compare them with Cal.com. Reading bookings sends no emails.

Connect Cal.com to Codex today

Start free

7 days free. No card required. Disconnect any time.