Post a Slack alert with the time and join link when a meeting is booked
Every Cal.com or Calendly booking posts to Slack with the prospect, company, meeting time and join link, so the team sees wins live and the AE knows when to show up.

Why teams run it
Booked meetings stop living only in one rep's calendar.
Set it up in Master Inbox
- In Master Inbox, open Settings, then Workflows, and click Add a workflow.
- Name it Post a Slack alert with the time and join link when a meeting is booked.
- Set the trigger to Meeting Booked and choose From Cal.com or Calendly.
- Add the action Notify in Slack: Post the prospect, company, meeting time, meeting URL and thread link to #meetings.
- Save the workflow and switch it to Active.
Before you start, connect Slack, Cal.com or Calendly under Settings, Integrations.
Or create it with the API
Everything in the workflow builder is also in the Master Inbox API. This request creates the same workflow. Replace the example ids with your own label, list and campaign ids from GET /workflows/filter-fields.
curl -X POST https://api.masterinbox.com/api/api-webhook/v1/api/workflows/create-workflow \
-H "Authorization: Bearer $MASTER_INBOX_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"name": "Post a Slack alert with the time and join link when a meeting is booked",
"trigger_type": "meeting_booked",
"trigger_config": {},
"action_configs": [
{
"action_type": "slack_notify",
"payload_variables": [
"name",
"company_name",
"label_names",
"text",
"thread_url"
],
"show_draft": true
}
]
}'Full reference: workflow API guide and API docs.
Or ask Claude, ChatGPT or Grok to build it
Our workflow guide is written for AI agents to read. Give your assistant your API key and this prompt:
Read https://app.masterinbox.com/public-workflow-api.md and use my Master Inbox API key to create this workflow: "Post a Slack alert with the time and join link when a meeting is booked". First call GET /workflows/filter-fields and look up my label, list and channel ids, then create the workflow and tell me what you set up.Questions
What if the person who booked is not in Master Inbox?
The Slack notification still posts with the booking details even when the email matches no lead.
Can I include the reply that led to the booking?
Yes. Add the last message variable to the Slack payload.
Can I build this workflow through the API?
Yes. Send the create-workflow request shown on this page with your Master Inbox API key. The API checks the payload first and lists every problem by field if anything is off.
Which plan includes this?
This workflow works on the Team plan. Every plan has unlimited users and starts with a free 7-day POC.
Learn more
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Run this on your own inboxes
Free 7-day POC. Unlimited users on every plan.
