GeoLetter

A world map where you leave a marigold, a candle or a letter at a place that belonged to someone: the plaza where your grandmother sold tamales, the beach where a teacher explained waves, the bakery where your mother bought sweet bread on Sundays. The person can be alive or gone.

Every word left on the map is read first by Gemma, an open-weight model running on the same small server as the app. Gemma decides what can stay, translates letters for readers in other languages, and can help someone who doesn't know how to start. Nothing anyone writes is sent to an outside AI service.

Live: https://geoletter.tech

It is meant to feel like a book of condolences, not an app: paper, ink, one serif face, one candle colour, no counters and no features list. It's a tribute, not a product.

A 90-second demo: narrated (voice by ElevenLabs), silent, and vertical for phones (narrated, silent).

What you can do

• Leave something at a place. Touch the map or search for a place. Leave a marigold, a candle, a letter, or something of theirs ("his blue harmonica").
• The guardian reads it first. Anything written goes into a queue. Gemma reads it and answers in structured JSON (allow, reason, categories, lang). Hate, harassment, threats, sexual content, spam and other people's private data (phone numbers, home addresses, CPF/SSN, emails) are turned away. Grief, anger at a loss, harsh words about a dead father and dark humour are allowed. If a letter is kept back, only its author sees why, in the language they wrote in.
• Read it in your language. Each letter keeps the language it was written in. A reader whose browser speaks another language can ask Gemma for a translation. Each translation is made once and cached.
• Help me find the words. Write loose memories ("she sang off-key on Sundays; the mango tree in Bauru; I was twelve") and Gemma drafts a short letter using only what you wrote. You edit it before leaving it.
• Seal it to the place. A letter can be sealed so that it only opens for someone whose browser reports a position within 100 m to 1 km of the spot (200 m by default). Everyone else sees an unlit candle and how far away they are.
• Tell someone who is alive. Optionally give the recipient's email. After the guardian approves the letter, they get one short note: "Someone left a letter for you in [place]", with a link. The letter itself is never in the email. A sender can trigger at most 3 notes a day, one person gets at most one a day, and every note has a link to stop them for good. Only a keyed hash of an opted-out address is kept; the address itself is deleted as soon as the note is sent or the letter is refused.

Why open and local AI

• These are intimate memories. People write about a dead parent, an illness, a friend who moved away. Sending that text to a hosted model means a third party reads it before any human does. Here the model runs on the same machine as the database, through Ollama on 127.0.0.1. The letters never leave the server to be moderated or translated.
• A memorial should outlast an API. Hosted models get deprecated, repriced or switched off. A letter left today should still be readable, translatable and protected in ten years. Gemma's weights are a file on disk. As long as the file and a runtime exist, GeoLetter keeps working.
• Cost. A hobby memorial has no business model and shouldn't need one. A 2-billion-effective-parameter Gemma on two ARM cores costs nothing per letter. It is slower than an API, so the app is built around a visible queue instead of pretending to be instant.

Gemma is not a feature on top of the app. Without it there is no moderation, so nothing written can be published; there is no translation and no drafting. Turn Ollama off and the map only accepts flowers and candles without words.

Architecture

browser (MapLibre GL, plain JS, no build step)
   │  HTTPS
nginx ── geoletter.service (Node 24, TypeScript run directly, SQLite via node:sqlite)
   │         ├── guardian worker: one queued offering at a time ─┐
   │         ├── translate / draft (jump ahead of moderation)    ├─> Ollama 127.0.0.1:11434
   │         │                                                   │     Gemma 4 E2B, 2 threads,
   │         │                                                   │     one call at a time
   │         ├── mail driver: "log" (default) or SMTP
   │         └── Nominatim proxy (1 req/s, cached in SQLite, own User-Agent)
   └── tiles: OpenFreeMap (open style, no key), data © OpenStreetMap

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