3 min read

HealthKaaati: A Food Diary You Talk To

HealthKaaatiMCPClaudeSpringReact

I wanted a food diary that feels like a chat with a friend. So I built HealthKaaati.

I tell Claude about my day in my own words:

"3 idlis with sambar and coconut chutney for breakfast, curd rice and poriyal for lunch, a 30 minute walk in the evening, weight 72.4."

Claude estimates the calories, picks the times, and saves the meals, the walk and the weight in one go. A moment later, it is all on my phone.

HealthKaaati on a phone: the Today screen, foods before a symptom, and calories per day

Screens with sample data.

How it works

HealthKaaati is an MCP server. MCP lets Claude call tools on a server I run, so Claude Desktop or claude.ai can read and write the diary directly.

Talking is the main way in. The web app is a clean window over the same diary. One Spring Boot process serves both, through the same service layer, so a dosa added by hand and a dosa added from chat follow the same rules.

Friendly estimates

Every home has its own sambar, so in v1 Claude estimates the calories, protein, carbs and fat for each item. Each number carries a ~, and a time Claude picked is marked est. The diary is about the pattern, so a close estimate is all it needs.

Patterns over time

The History screen shows the foods I ate in the hours before each symptom, beside how often those foods appear in general. Idli on Monday, parotta on Friday, pongal on Sunday: the diary lays it all out, side by side.

It only records

HealthKaaati keeps to one job: it records and it shows. It shares facts only, and leaves advice and diagnosis to doctors. Medicines stay out of the diary. Every page ends with a gentle reminder that these are associations to notice.

Small touches

  • One message can hold many entries, and each entry saves on its own.
  • Every entry carries an idempotency key, so a retried call saves it once.
  • Each entry records which client wrote it, such as Claude Desktop.
  • The day ends at midnight in my own time zone.
  • Deleting a meal by hand comes with an undo.

What v1 is

  • Java 21 and Spring Boot, with PostgreSQL.
  • A mobile-first React web app that installs as a PWA.
  • Sign in with Google, and OAuth for claude.ai connectors.
  • Data export and account deletion.
  • Docker, nightly backups and CI, on a small Hetzner box.
  • Invite-only for now, as a showcase.

About 70 commits in one month, from an empty folder to a working v1.

Next

  • A food list for common Tamil dishes like idli, dosa, sambar and rasam, for sharper estimates.
  • Richer patterns as the diary grows.
  • A photo of the plate, so logging is one tap.

When logging takes one sentence, logging becomes a habit. That is the whole idea.

HealthKaaati is live at health.kaaati.com, invite-only for now.

— Vicky KS