Drawing 02.10, health and accountability
F3 Queen
A closed-cohort fat-loss accountability app I built for myself and a small group. A daily check-in that takes under a minute feeds a private cohort feed, personal trends, and a post in the cohort's own Slack.
| No. | Part | What it does here |
|---|---|---|
| 1 | Phone | The daily check-in, the cohort feed, and personal trends. |
| 2 | Next.js on Vercel | Server actions for check-ins and meals, sign-in, and the redaction of private numbers. |
| 3 | Neon Postgres | Check-ins, meals, cohorts, feature flags, and encrypted Slack tokens, through Drizzle. |
| 4 | Vercel Blob | Resized check-in photos. |
| 5 | Claude | Estimates a meal's macros from a photo or a description, under a daily cap. |
| 6 | Cohort Slack | Each cohort's own workspace, connected by OAuth; every check-in posts and updates itself. |
| 7 | SendGrid | Sign-in links and one-time codes. |
Why it exists
This one was mine. I wanted real accountability for a cutting season without another bloated fitness app, so I built the tool I wanted to open every morning. It worked: my BMI and body fat came down while I ate well instead of starving.
The interesting part
Everything is built around a check-in that has to take under a minute, or nobody keeps doing it. Onboarding runs the BMR and TDEE math to set each person's targets, and feature flags let me turn pieces on for one person at a time. The cohort feed hides private numbers before they leave the server, so accountability never turns into comparison.
Each cohort connects its own Slack workspace, and its token is encrypted before it is stored. Every check-in posts itself to the cohort's channel and updates that post when it is edited, and an admin can post a recap. Meals can be logged from a photo: Claude estimates the macros, under a daily cap on calls.
What it does
- A daily check-in built for a phone, under a minute
- Targets from BMR and TDEE math at onboarding
- A cohort feed with private numbers hidden
- Each check-in posted to the cohort's own Slack
- Meal macros estimated from a photo by Claude
Plates
