# Build brief — a focused alternative to Proton Unlimited

> **Verdict:** Not faithfully · **Buildability:** 26/100 · **Category:** Security
> **Source:** https://www.canitbevibecoded.com/proton-unlimited
> Independent editorial assessment from Can It Be Vibe Coded? Not affiliated with, endorsed by, or derived from Proton Unlimited. Verify current pricing and capabilities before acting.

## Context

**Proton Unlimited** — Encrypted email, calendar, VPN, password manager, and cloud storage. It currently costs $12.99/mo.

Do not mistake the interface for the product. Proton Unlimited's durable value is security, infrastructure, trust, which a solo one-shot build cannot reproduce responsibly. The prompt therefore builds only the closest honest personal consolation tool.

This brief describes a focused, single-operator replacement for the part of Proton Unlimited 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

Build a local diagnostic or backup companion for privacy suite; do not claim to replace audited security, identity, VPN, or cloud-storage infrastructure.

- Prototype the workflow, but rely on audited libraries and established security tools.
- A responsive interface with real empty, loading, success, and error states.

## Requirements

### Functional

- Desktop development machine.
- User-controlled storage target.
- Documented threat-model limits.
- Explicit README warning that this is a consolation build, not a production replacement.

### 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 the closest honest consolation tool inspired by Proton Unlimited; do not claim to replace its structural moat.
Use exactly this stack: Go 1.24 + SQLite.
Primary job: Build a local diagnostic or backup companion for privacy suite; do not claim to replace audited security, identity, VPN, or cloud-storage infrastructure.
Start from an empty folder and create the complete working project.
Make the default mode single-user and private.
Store user data locally unless the core job requires the declared self-hosted database.
Do not add analytics, telemetry, ads, or third-party accounts.
Put every secret and external credential in .env and provide .env.example.
Use realistic sample data that is clearly labelled and easy to delete.
Implement the smallest polished interface that completes the core loop end to end.
Include clear empty, loading, validation, success, and failure states.
Add import and export so the user is not trapped in the app.
Use accessible keyboard navigation, labels, focus states, and sensible contrast.
Validate untrusted input and never log secrets or private file contents.
Deliberately exclude these paid-product advantages: calendar-provider edge cases and timezone correctness; audited cryptography and incident response; global network or redundant storage infrastructure.
Do not fake integrations, network effects, proprietary data, model quality, compliance, or security claims.
Where an external API is optional, keep the app useful without it and explain the degraded mode.
Write focused unit tests for the data model and the most important workflow.
Add one end-to-end smoke test that proves the core loop works.
Create a README with setup, permissions, architecture, data location, backup, and limitations.
Add scripts for install, development, test, build, and a production-style local run.
Run the tests and build before finishing, then fix errors rather than merely describing them.

## 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:

- Calendar-provider edge cases and timezone correctness.
- Audited cryptography and incident response.
- Global network or redundant storage infrastructure.
- Identity, credit, or broker-removal operations.
- Trust, audits, and counterparties matter more than feature parity.
- Reliability at the vendor's scale is an operations problem, not a prompt.

## What you still own after launch

- 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

**High consequence.** Use this as a prototype or personal aid. Keep a qualified human and an established provider in the loop for consequential decisions.

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) — Open-source file sync, sharing, and collaboration server
- [Syncthing](https://github.com/syncthing/syncthing) — Peer-to-peer continuous file synchronization

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