Security Architecture

Your invoices stay
on your machine

JuSenseSheet is built local-first. No cloud account required, no data uploaded without your consent, no telemetry phoning home. Every security decision was made to protect your clients' financial data.

AES-256-GCM
Encryption at rest
0 bytes
Uploaded by default
BYOK AI
Your API key, your control
Offline
License validation

Security by design, not by policy

These aren't promises — they're technical constraints built into how JuSenseSheet works.

AES-256-GCM Encryption

Every PDF you drop into JuSenseSheet is encrypted at rest using AES-256-GCM — the same standard used by banks and government systems. The key is derived from a machine-local secret and never leaves your device.

Algorithm: AES-256-GCM
Key derivation: PBKDF2-SHA256
Nonce: 96-bit random per file

100% Local Processing

JuSenseSheet runs entirely on your computer. PDF parsing, field extraction, vendor matching, and export generation all happen locally using Python. No internet connection is needed for normal operation.

  • Works fully offline
  • No cloud dependency
  • Data stays on your machine

Zero Telemetry

JuSenseSheet does not collect usage analytics, crash reports, or any behavioural data. There are no tracking pixels, no error-reporting SDKs, and no third-party analytics embedded in the application.

What we never collect:

Invoice data · Vendor names · File names · Usage patterns · Keystrokes

BYOK AI — Your Keys, Your Control

AI fallback (Claude / OpenAI) is opt-in only. When enabled, you supply your own API key. JuSenseSheet applies PII redaction before sending any content, stripping amounts, names, and addresses from the payload.

  • Disabled by default
  • PII redacted before API call
  • API key stored locally only

Offline License Validation

Pro license keys are HMAC-signed and validated entirely offline. Activating your license does not phone home to a licensing server. The key embeds your tier, seat count, and expiry — all verified cryptographically on-device.

Signing: HMAC-SHA256
No activation server
Works air-gapped

Full Data Portability

Your data is stored in a local SQLite database and encrypted PDFs on your own disk. Export everything as CSV, XLSX, or QBO at any time. Uninstalling JuSenseSheet leaves no residue — delete the folder and it's gone.

  • SQLite DB — open standard
  • No vendor lock-in
  • Clean uninstall

Network transparency

Every outbound connection JuSenseSheet can make — and why.

Destination When What's sent Required?
api.anthropic.com Only if BYOK AI enabled + low-confidence invoice Redacted layout text (no PII) Optional
api.openai.com Only if BYOK AI enabled + low-confidence invoice Redacted layout text (no PII) Optional
jupitersense.com Never — no update checks or license pings Nothing Never
Any analytics / tracking Never Nothing Never

You can verify this yourself: JuSenseSheet is a local FastAPI server — run it with a packet sniffer and confirm.

Responsible disclosure

Found a security issue in JuSenseSheet? Please report it privately. We take vulnerabilities seriously and will respond within 48 hours. We do not operate a formal bug bounty program yet, but we will credit you publicly (if you wish) after a fix is shipped.

security@jupitersense.com

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Free for 50 invoices/month. No account needed. Download and run in under two minutes.

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