Ermis

2026 In progress

One place for a group trip, instead of it scattered across a dozen tools

A self-hostable, collaborative trip planning app where a group organises flights, itinerary, expenses and decisions on one canvas, synced live.

Personal project in progress, source kept private for now.

Stack

Java
Spring Boot
Angular
Tailwind CSS
PostgreSQL
Redis
FastAPI
LangGraph
Docker

The problem

Planning a group trip ends up split across a chat, a spreadsheet, a Drive folder, loose documents and forwarded emails, and nobody has the full picture. Ermis brings flights, itinerary, expenses and decisions into one place the whole group sees at once.

What it does

A collaborative itinerary the whole group edits and sees update live.
Shared expenses with flexible splits and an automatic settle up at the end of the trip.
A trip overview with the essentials at a glance: countdown, budget and group balance.
Self-hostable and installable as an app, with offline support.

How it is built

A monorepo with Angular and Tailwind on the frontend, Spring Boot for the transactional API and its own authentication (JWT plus refresh tokens), and PostgreSQL with Redis as the WebSocket/STOMP broker for live collaboration.

A Python microservice with FastAPI and LangGraph handles the AI side: generating itineraries, parsing bookings from email and proactive suggestions, with pgvector for semantic memory.