Products / Case study
Campfyr
Travel
One shared home for a group trip.
The plan, the people, the money and every photo, in one app that keeps working when the signal doesn't. Plan day by day with real road routes, keep tickets and stays in one wallet, split expenses and settle up by UPI, and share photos phone to phone.
- Platforms
- Android, iOS
- Status
- Pre-release
- Built by
- Devian Labs, in-house
- Stack
- Flutter, Dart, SQLite, Firebase
01The problem
“800 photos across six phones. You want about 30 of them.”
A group trip lives in five apps at once: the plan in WhatsApp, the tickets in Drive, the route in Maps, the money in a spreadsheet and the photos on six different phones. Nothing agrees, and half of it doesn't work when the signal drops in the hills.
02What we built
The product.
Plan
A day strip and day map with real road routes, distance and drive time per leg, and stops for part of the group.
Trip wallet
Tickets, stays, transport, contacts and documents as cards with a copyable PNR, Call and Directions.
Expenses
Paise-exact equal and custom splits, balances, settle-up in the fewest payments, and Pay via UPI.
Photo memories
Photos shared phone to phone, with duplicates and near-duplicates caught, so the group keeps the 30 that matter.
Trip experience
Offline weather, rain nudges, and peaks, viewpoints, food and fuel discovered along the route.
Recap
Days, places, kilometres and spend after the trip, with shareable story cards.
03Under the hood
The engineering we own.
- 01
A local-first sync engine
Every change is an operation in an append-only log, ordered by a Lamport clock. Each field is its own last-writer-wins register, and peers compare version vectors to send only what's missing. Applying operations is commutative and idempotent.
- 02
An encrypted phone-to-phone mesh
Phones find each other over mDNS and talk over a WebSocket mesh. Every frame is sealed with ChaCha20-Poly1305 using a per-trip 256-bit key that travels only in the invite QR.
- 03
A cloud that can't read your trip
The operation log is mirrored to the cloud already encrypted. Membership is proven with a key-derived proof checked by security rules, tested in the emulator and against production.
- 04
Bandwidth-aware photo sharing
Phones gossip a thumbnail catalogue and pull originals only on request, in 64 KB chunks. SHA-256 catches identical files and a 64-bit perceptual hash catches near-duplicates.
- 05
Procedural destination art
Each trip gets a living illustration rendered from code: destination, landmarks, weather, local time, sun and moon position, moon phase and hemisphere-aware seasons.
04Key decisions
Offline first, sync second
Everything works without internet as the baseline. Connectivity is a bonus, not a requirement.
Privacy through encryption
The trip key never leaves the group, so the server stores data it cannot read.
Fair pricing
The first trip is free and joining a trip is always free.
05Where it is today
Pre-release
Campfyr grew out of an earlier prototype for offline group travel. It's now in pre-release on Android and iOS, with store listings coming soon.
For your project
Need something like Campfyr?
The team and the engineering behind Campfyr are available for client projects and long-term partnerships.
Mobile apps
Android and iOS apps in Flutter, offline-first when it matters, with payments and store releases handled.
AI agents and MCP
MCP servers, agent tooling and LLM features with structured output, built with permissions in mind.
Backends and APIs
APIs, auth, databases, sync engines, security rules and edge workers, designed to be secure and cheap to run.
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