CoS Briefing Build Kit
Self-serve · Function: Cross-functional · Where it runs: Google Workspace Studio + Apps Script
A daily email briefing of your meetings, email, Gemini notes, and Drive activity, tagged by your role (RACI) — built as a six-step Workspace Studio flow you can set up yourself, one module per Office Hours session.
Problem
Staying on top of a full calendar and inbox means rebuilding the same picture every morning: what happened yesterday, what you own, what's coming up, and what needs a decision. A single Chief of Staff Gem tried to do this in one prompt and wasn't reliable — it pulled meetings from other people's calendars, invented context, and gave different answers on the same day.
What it does
- Reads your own calendar, inbox, Gemini meeting notes, Drive files, company holidays, and time off.
- Decides the facts in code: who organized each meeting, the notes and action items that belong to it, what's noise.
- Uses two worker/checker pairs of Gemini skills to tag your role in each meeting and email, and to write a short briefing.
- Emails you a formatted briefing with working links to every meeting and email.
Who owns it
- Business owner: Rob Bowron, AI CoE
- CoE AI Solution Lead: Rob Bowron
Where it runs
Google Workspace Studio. Two Apps Script custom steps (CoS Gather, CoS Send) and four Gemini skills in Ask Gemini steps. Everything you need — code, skills, prompts, and setup steps — is in the module pages below.
| Step | Type | What it does |
|---|---|---|
| 1. CoS Gather | Apps Script custom step | Reads your calendar, email, Gemini notes, Drive, holidays, and time off. Decides the facts (who organized what, prior meeting notes, your action items, noise). Gives every item a short ref (E3, M1) and keeps the URLs to itself. |
| 2. CoS Analyst | Gemini skill in an Ask Gemini step | Links emails to meetings and assigns your RACI role. |
| 3. CoS Analyst Checker | Gemini skill in an Ask Gemini step | Checks every call and returns a corrected version. |
| 4. CoS Writer | Gemini skill in an Ask Gemini step | Writes the short briefing. |
| 5. CoS Writer Checker | Gemini skill in an Ask Gemini step | Checks the briefing and returns a corrected version. |
| 6. CoS Send | Apps Script custom step | Turns refs back into links, formats the email, and sends it to you. |
Data it touches
| Data source | Access path |
|---|---|
| Your Google Calendar | Read-only, by CoS Gather under your own account |
| Your Gmail (including Gemini notes emails) | Read-only, by CoS Gather under your own account |
| Google Drive files you own | Read-only (file names and dates), by CoS Gather |
| The briefing email | Sent to you only, by CoS Send |
The Gemini steps never search Workspace: web and Workspace search are turned off, and they only see the data CoS Gather hands them.
Demo
Session 11 — Building a Chief of Staff in Workspace Studio
The curriculum
One module per AI Office Hours session, in the order the data flows. Each module page has the setup steps, the code or skills, what we'll debug live, and a stretch exercise.
| Session | Date | Module |
|---|---|---|
| 12 | Thursday, 5 November 2026 | 1 — Gather (Apps Script) |
| 13 | Thursday, 19 November 2026 | 2 — Analyst + Analyst Checker |
| 14 | Thursday, 3 December 2026 | 3 — Writer + Writer Checker |
| 15 | Thursday, 17 December 2026 | 4 — Send (Apps Script) + the full flow |
| 16 | Thursday, 14 January 2027 | 5 — Build your own |
Setup checklist (about 10 minutes, before Session 12)
- Ask your Workspace admin to allow custom steps in Workspace Studio (Admin Console → Apps → Google Workspace → Workspace Studio → Custom steps settings). Nothing else works without this.
- Confirm you can open script.google.com and Workspace Studio with your work account.
- Do Module 1, Part 1 (create the CoS Gather project and run
testGather). If the log shows your meetings, you're ready. - You do not need a Google Cloud project or any Apps Script "Services."
What we learned building it
- Code fetches and decides facts; AI makes judgment calls. Anything with one right answer (who organized a meeting, which notes belong to it, links, holidays) lives in code. A model gets those right most of the time, which isn't good enough.
- Keep AI steps off your Workspace. Turn web and Workspace search off on every Ask Gemini step. With search on, Gemini pulled other people's meetings into the briefing.
- The AI never sees a URL. Items are referenced by short IDs. In testing, a model changed one character in a calendar link even when told never to touch links.
- Gems: short instructions plus well-organized, correct worked examples in Knowledge worked best.
- Skills: the skill ignored our source file. Put everything — rules, output shape, and examples — in the instructions. Longer instructions are fine.
- "Ask a Gem" can no longer be added to new Studio flows, and Gems are being retired for business accounts (no sooner than March 1, 2027). Build new work as skills.
- Checkers should correct, not just flag — flows run straight through, so there's no "send it back." But a checker can claim a fix it didn't make, so formatting and links are handled in code.
Patterns reused
- Worker/checker pairs, as in the CRM Brief Writer pipeline
What's next
- Google Chat, once the Chat API can be enabled (see Known limits).
Known limits
- Google Chat isn't included. Reading it safely needs the Chat API, a Google Cloud project, and an admin setting. Letting Gemini search Workspace for it is exactly what we're avoiding.
- Sharing: while these are test deployments, each person needs edit access to both Apps Script projects (or their own copies). Company-wide use means publishing the add-on internally through your admin.
- Time zone and name come from the person running the flow: their calendar's time zone and their email address.
Changelog
- 2026-11-03 — Initial entry created, with curriculum Sessions 12–16.