# Build brief — a focused alternative to Sync.com

> **Verdict:** Not faithfully · **Buildability:** 31/100 · **Category:** Cloud Storage
> **Source:** https://www.canitbevibecoded.com/sync-com
> Independent editorial assessment from Can It Be Vibe Coded? Not affiliated with, endorsed by, or derived from Sync.com. Verify current pricing and capabilities before acting.

## Context

**Sync.com** — Back up and share selected folders with client-side encryption and versioning. It currently costs $8/mo.

A consolation build is possible, but the paid product's decisive value sits outside a solo rebuild. For Sync.com, back up and share selected folders with client-side encryption and versioning. The hard boundary is zero-knowledge architecture, mature sync clients, sharing controls, and support, plus reliability, durability, and cross-device sync.

This brief describes a focused, single-operator replacement for the part of Sync.com that is genuinely reproducible. It is deliberately narrower than the product it replaces, and it says so in writing. Build the useful core; do not pretend to have rebuilt the rest.

## What you are building

Back up and share selected folders, encrypt files client-side, track versions, and restore them from user-owned object storage.

- Build a focused single-user workflow with real persistence, search, and export.
- A responsive interface with real empty, loading, success, and error states.

## Requirements

### Functional

- User-owned server or S3-compatible bucket.
- PostgreSQL.
- MinIO or object storage.
- Desktop filesystem permissions.

### Data and integrations

- Backup key stored offline.

Each of these needs a real account, credential, or quota. Set them up before writing feature code.

### Non-functional

- Accessibility: semantic markup, labelled controls, visible focus, and reduced-motion support.
- Security: server-side secrets, validated input, and no credentials in the client bundle.
- Reliability: retries with backoff on external calls, and a clear failure state when a provider is down.
- Portability: the operator can export their data and leave without losing it.

## Implementation brief

Build a closest honest personal substitute for Sync.com in an empty repository.
Use Next.js 15, TypeScript, PostgreSQL, MinIO, and a Tauri 2 sync client; do not offer alternative stacks.
The core loop is: back up and share selected folders, encrypt files client-side, track versions, and restore them from user-owned object storage.
Make the first run work locally with one documented command.
Store all user data locally by default and make export straightforward.
Put secrets in .env, ship .env.example, and never commit credentials.
Build a desktop client that watches explicitly selected folders and ignores configured patterns.
Chunk, hash, compress, and encrypt files locally before uploading to the configured object store.
Store version metadata, tombstones, device identifiers, and integrity checks in PostgreSQL.
Provide upload and restore queues with pause, retry, bandwidth limits, and resumable transfers.
Add file history, point-in-time restore, key export, storage usage, and scheduled restore tests.
Document the failure model and make clear that one server is not a complete backup strategy.
Include clear empty, loading, success, and recoverable error states.
Add input validation, safe filenames, and graceful handling of unavailable APIs.
Write focused tests for the core transformation and one end-to-end happy path.
Create a README with setup, architecture, permissions, data location, and backup steps.
Do not add accounts, billing, telemetry, analytics, or a hosted control plane.
Do not claim to reproduce proprietary data, network liquidity, regulated access, or frontier infrastructure.
Deliberately leave out multi-provider consumer sync at global scale.
Deliberately leave out guaranteed durability or ransomware recovery.
Deliberately leave out shared-drive administration, mobile apps, and enterprise compliance.
Finish by running the tests and listing the exact commands used.

## Delivery standard

- Inspect the repository first, then write a short implementation plan before writing code.
- Deliver the smallest complete end-to-end workflow first; every primary control must work against persisted data.
- Use real validation and storage; never substitute fake dashboards, decorative controls, hard-coded success states, or mock integrations.
- Include responsive layouts plus genuine empty, loading, success, validation, and failure states.
- Keep secrets server-side in environment variables, provide .env.example, and never commit credentials or user data.
- Add structured logs around every external call and return actionable errors without leaking sensitive details.
- Write unit tests for the core logic and one automated test of the main user journey.
- Finish with a README covering setup, architecture, data location, backups, tests, deployment, and known limitations.

## Acceptance criteria

- [ ] A clean install starts the app using only the README and .env.example.
- [ ] The primary journey works from first visit through saved result, reload, edit, export, and deletion where applicable.
- [ ] Invalid input, missing configuration, provider failure, and an empty database each have a usable state.
- [ ] The interface works at 390px and 1440px, is keyboard navigable, and shows visible focus on every control.
- [ ] Tests, type checking, linting, and a production build all pass with no ignored failures.
- [ ] No part of the interface implies a live integration, security guarantee, or scale capability that was not actually built and verified.

## Non-goals

Do not build these, and do not claim to have replaced them:

- Zero-knowledge architecture, mature sync clients, sharing controls, and support.
- Global sync network.
- Battle-tested conflict resolution.
- Ransomware recovery guarantees.
- Reliability at the vendor's scale is an operations problem, not a prompt.
- The last 20 percent is sync, migration fidelity, speed, and edge cases.

## What you still own after launch

- Secure credentials, rotate secrets, and handle provider rate limits.
- Run migrations, backups, restores, and dependency updates.
- Test the critical journey after every model, API, or hosting change.
- Monitor failures and fix the edge cases a first prompt will miss.

## Risk

**Operational risk.** The code is achievable; dependable data, integrations, and ongoing operations are the real cost.

Editorial confidence in this assessment: high. No independent one-shot implementation is linked yet.

## Prior art

Working open-source software you can read, fork, or borrow from before starting:

- [Nextcloud](https://github.com/nextcloud/server) — Mature open-source file sync and collaboration server

---

Generated by [Can It Be Vibe Coded?](https://www.canitbevibecoded.com) · Full report: https://www.canitbevibecoded.com/sync-com