Runs on the server
Public data and game state: real places, walking routes on actual streets, weather, the explore-walk planner and crew scores.
search_placeswalking_routeget_weatherplan_explore_walkgame_status
Personal, without reading your life.
Haunts is a phone app, a small server and an AI agent. The interesting part is where each piece of your data is allowed to go.
Watch what leaves the phone.
Pick a question. Each pill is a real message in the code path. Red ones are stopped at the phone.
The AI agent
One agent, two kinds of tools.
Claude plans on the server. Tools that touch the city run there; tools that touch your memory run on your phone and return a summary.
Runs on your phone
Your memory. The conversation pauses, the phone asks for permission once, answers from its own database and shows what it shared.
check_visitedmemory_querytaste_profilesaved_places
Privacy rules
Enforced in code, not in a policy.
No raw location on the server
The phone turns each GPS fix into a 60 m block ID and a date. Only those are uploaded.
Private zones never recorded
Home and other zones are filtered on the phone before anything is stored, and never leave it.
No live location for friends
The crew map hides today and shows no times, so nobody can see where you are right now.
Memory is end-to-end encrypted
Backups are encrypted on the phone with a recovery code; the server keeps bytes it cannot read.
The AI never sees your timeline
When a question needs your memory, the phone asks you, then sends a short summary only.
Delete means delete
Deleting the account removes every row you own, including drops and the encrypted backup.
By the numbers
Small app, real city.
67,316
blocks cover Bengaluru
65
neighbourhoods to own
60 m
per block, about one street corner
94
automated tests on the shared core and the API
The stack
What it is built with.
Mobile app
Expo SDK 57React Native 0.86expo-routerMapLibreexpo-location background trackingSQLitespeech in and outcamera
Server
Node 22Fastify 5PostgreSQL on NeonAWS EC2Caddy with automatic HTTPSsystemd
AI
Claude Opus 5.5tool use agentstructured JSON answersvisionprompt cachingrefusal fallback
Data and builds
OpenStreetMap: Overpass, Nominatim, Photon, OSRMOpen-MeteoGitHub ActionsGitHub ReleasesGitHub Pages