Deploy and Host Fanren Sync on Railway

Fanren Sync is a lightweight, self-hosted JSON synchronization service built with FastAPI. Originally designed to power the cloud save functionality for the "A Record of a Mortal's Journey to Immortality" SillyTavern character card, it provides a simple password-protected API for storing, loading, listing, and deleting JSON archives. Its minimal resource usage, asynchronous file operations, and persistent storage make it ideal for personal cloud save deployments.

About Hosting Fanren Sync

Hosting Fanren Sync on Railway provides an easy way to run your own secure synchronization server without managing a VPS or complex infrastructure. Railway handles deployment, networking, persistent storage, and automatic restarts while allowing the application to run from the official Docker image. Since Fanren Sync stores archives as JSON files on disk, attaching a Railway Volume ensures that save data persists across deployments and restarts. Once deployed, you simply configure a synchronization password, use the generated Railway public domain as your server address, and your client can immediately begin syncing archives through the REST API.

Common Use Cases

Cloud save server for the "A Record of a Mortal's Journey to Immortality" SillyTavern character card.
Personal self-hosted JSON archive synchronization across multiple devices.
Lightweight FastAPI-based storage service for small applications requiring simple authenticated JSON persistence.

Dependencies for Fanren Sync Hosting

Railway Persistent Volume (mounted at /app/data) for archive storage.
SYNC_PASSWORD environment variable for API authentication.

Deployment Dependencies

GitHub Repository: https://github.com/foamcold/fanren-sync
Docker Image (AMD64): foamcold/fanren-sync:amd
Docker Image (ARM64): foamcold/fanren-sync:arm

Implementation Details

Railway should deploy the official Docker image with a persistent volume mounted at /app/data.

Required environment variable:

SYNC_PASSWORD=your_secure_password

Internal application port:

Persistent storage:

/app/data

After deployment, Railway assigns a public domain. The application's base URL becomes:

https:///

Example API endpoints:

GET    //api/list
GET    //api/load?archiveName=
POST   //api/save
DELETE //api/delete?archiveName=

Why Deploy Fanren Sync on Railway?

Railway is a singular platform to deploy your infrastructure stack. Railway will host your infrastructure so you don't have to deal with configuration, while allowing you to vertically and horizontally scale it.

By deploying Fanren Sync on Railway, you are one step closer to supporting a complete full-stack application with minimal burden. Host your servers, databases, AI agents, and more on Railway.