Automating NetMcr Event Tracking with Node-RED, Home Assistant, and Google Calendar
Introduction
As part of any community, you likely have event announcements arriving via email: talks, venues, dates, agendas. Manually copying those details into Google Calendar takes time and can lead to mistakes.
In this post, we’ll show you how to build a flow using Node-RED and Home Assistant that reads NetMcr announcement emails, extracts the key details, and automatically creates Google Calendar entries — so you never miss a meetup.
Why Automate NetMcr Event Tracking?
- Timely reminders on all your devices (phone, tablet, work computer)
- Consistency in event details (venue, date, time, agenda)
- Shareability with others in the community
- Historical record of past talks and events without manual record keeping
Prerequisites
Make sure you have the following:
- Home Assistant up & running
- Node-RED installed and integrated with Home Assistant
- Google Calendar integration configured in Home Assistant (with valid credentials / OAuth)
- An email inbox/folder that receives NetMcr announcement emails (IMAP access)
Step 1: Import the Node-RED Flow
The following is the code, which can be imported directly in to Node Red.
[{"id":"ef8e7668a938ef13","type":"group","z":"17bf9644c8f14af7","style":{"stroke":"#999999","stroke-opacity":"1","fill":"none","fill-opacity":"1","label":true,"label-position":"nw","color":"#a4a4a4"},"nodes":["ef105138afb19864","588093991e4d5954","f62853687e465a24","4066152898d3e52b"],"x":14,"y":139,"w":932,"h":82},{"id":"ef105138afb19864","type":"e-mail in","z":"17bf9644c8f14af7","g":"ef8e7668a938ef13","name":"NetMCR-Grabber","protocol":"IMAP","server":"","useSSL":true,"autotls":"required","port":"993","authtype":"BASIC","saslformat":true,"token":"oauth2Response.access_token","box":"netmcr","disposition":"Read","criteria":"UNSEEN","repeat":"30","fetch":"auto","inputs":0,"x":120,"y":180,"wires":[["588093991e4d5954"]],"outputLabels":["payload"]},{"id":"588093991e4d5954","type":"function","z":"17bf9644c8f14af7","g":"ef8e7668a938ef13","name":"Talk Extractor","func":"// split the payload by the agenda, keep the 2 piece\n\n// split the payload by inclusiveness, keep the first piece.\n\nvar paras = msg.payload.split(\"**\") \nvar time = paras[4].split(\"\\n\");\n\nvar agenda1 = msg.payload.split(\"** Agenda\")\nvar agenda = agenda1[1].split(\"** Inclusiveness\")\n\nreturn { event : paras[1].split(\"\\n\")[0], \n venue : paras[2].split(\"\\n\")[0], \n date : paras[3].split(\"\\n\")[0] , \n time : time[0],\n agenda : agenda[0]\n}\n","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":320,"y":180,"wires":[["f62853687e465a24"]]},{"id":"f62853687e465a24","type":"function","z":"17bf9644c8f14af7","g":"ef8e7668a938ef13","name":"Event Formatter","func":"// Conver the output from Talk Extractor and convert to \n// a format for the calendar add function.\n\n/*\nevent : paras[1].split(\"\\n\")[0], \nvenue : paras[2].split(\"\\n\")[0], \ndate : paras[3].split(\"\\n\")[0] , \ntime : time[0],\nagenda : agenda[0]\n*/\n\n// Thursday, 12th June\n\nvar fixedDate1 = msg.date.split(\" \")[2].trim(); // 12th\n fixedDate1 = fixedDate1.substr(0, fixedDate1.length - 2);\nvar fixedDate2 = msg.date.split(\" \")[3].trim(); // June\nvar fixedDate3 = new Date().getFullYear() // Current year or current year +1 if January\n if (fixedDate2 == \"Jan\") {\n fixedDate3 = new Date().setFullYear(fixedDate3.getFullYear() + 1)\n }\n\n\nvar fixedDate = fixedDate1 + \" \" + fixedDate2 + \" \" + fixedDate3;\n\nvar startTime = new Date(fixedDate + \" \" + msg.time.split(\"-\")[0].trim() + \":00\");\nvar endTime = new Date(fixedDate + \" \" + msg.time.split(\"-\")[1].trim() + \":00\");\n\nreturn { \n// payload : { \n title : msg.event, \n location : msg.venue, \n start : startTime.toISOString(), \n end : endTime.toISOString(),\n description : msg.agenda,\n date: msg.date,\n time: msg.time\n// }\n}\n","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":520,"y":180,"wires":[["4066152898d3e52b"]]},{"id":"4066152898d3e52b","type":"api-call-service","z":"17bf9644c8f14af7","g":"ef8e7668a938ef13","name":"Tech Calendar Updater","server":"","version":7,"debugenabled":true,"action":"","floorId":[],"areaId":[],"deviceId":[],"entityId":[],"labelId":[],"data":"{ \t \"summary\": msg.title, \t \"description\": msg.description, \t \"start_date_time\": msg.start, \t \"end_date_time\": msg.end, \t \"location\": msg.location \t}","dataType":"jsonata","mergeContext":"","mustacheAltTags":false,"outputProperties":[{"property":"payload","propertyType":"msg","value":"","valueType":"results"}],"queue":"none","blockInputOverrides":false,"domain":"google","service":"create_event","x":810,"y":180,"wires":[[]]}]Step 2: How It Works
- NetMCR-Grabber: Checks your NetMcr-announcement inbox via IMAP for new, unseen mails. The email should be sorted in to it's own folder for ease of extraction.
- Talk Extractor: Parses out
title,venue,date,time,agendafrom email content (NetMcr’s format). - Event Formatter: Converts date + time to ISO8601, sets correct year, handles formatting of start / end times.
- Tech Calendar Updater: Calls Home Assistant’s Google Calendar service (e.g.
google.create_event) to create the event. You will need to have created the google calendar and shared it with Home Assistant.
Step 3: Customising for NetMcr
- Double-check you have the NetMcr email format correct (how announcements are structured, where "Agenda" etc appears).
- Adjust the split/parsing logic in the “Talk Extractor” if the announcement format changes (“** Agenda”, “** Inclusiveness”, etc).
- Time zone settings: ensure Home Assistant / Google Calendar are using the correct zone (UK / BST / GMT).
Troubleshooting
| Issue | Likely Cause | Solution |
|---|---|---|
| Event created at wrong time | Time zone mismatch or parsing of time segment failed | Check msg.time, ensure the /-delimited times map properly; adjust for BST/GMT |
| Missing event details | Email content changed format or tags moved | Update the function node (“Talk Extractor”) string splitting accordingly |
| Google Calendar auth errors | Bad credentials or token expired | Refresh OAuth credentials, test google.create_event manually |
Failsafe
To avoid disappointment, when you have created your calendar, populate it with a recurring placeholder for the second Thursday of the month. This is to give you advanced notification, since the emails don't always come out with plenty of notice. In addition, some events may change their dates.
Conclusion
With this setup, every time NetMcr sends out an announcement, your Google Calendar will automatically get the full event: title, venue, date/time, agenda. No more manual copy-pasting.
👉 Try pulling the flow above into Node-RED, connect it to your NetMcr announcement inbox, test with an actual email, and see the event pop up in Google Calendar.
Alternatively, if you would like access to ready made calendar (which may contain over events in the future), try this:
About the author
Tim Wilkes is a UK-based security architect with over 15 years of experience in electronics, Linux, and Unix systems administration. Since 2021, he's been designing secure systems for a telecom company while indulging his passions for programming, automation, and 3D printing. Tim shares his projects, tinkering adventures, and tech insights here - partly as a personal log, and partly in the hopes that others will find them useful.
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