Security you can verify.
We're a security-first product, so we publish exactly what we do — and only claim what we can prove. Here is the real architecture, in the same words as our engineering docs.
Your clipboard is yours, and nothing leaves your Mac by default — AES-256-GCM encrypted, Secure-Enclave-wrapped on capable Macs, fully on-device, with an audit-logged chokepoint that always redacts the results agents and automations see.
Encrypted before it touches disk.
AES-256-GCM at rest
Every clipboard item is authenticated-encrypted with a unique nonce and salt — confidentiality and integrity on each record.
Per-item HKDF-SHA256 keys
Keys are derived per item from a random 256-bit master key (v2 envelope). Legacy v1 items stay decryptable via envelope versioning — no forced re-encryption.
Secure Enclave key wrapping
On Macs with a Secure Enclave, the master key is stored wrapped by a non-extractable enclave key that never leaves the hardware. Check which is active under Settings → Security → Key storage.
Keychain fallback, device-local
Macs without a Secure Enclave use Keychain-only storage: this-device-only, non-synchronizable, and readable only while the Mac is unlocked.
Biometric user-presence
Touch ID / passcode presence is enforced at app unlock, so your history is sealed to you — not just to your login session.
No cloud, no telemetry
Secret detection, semantic search, content analysis and OCR run locally via Apple frameworks. No content is sent anywhere. No analytics, no ads, no data sale.
A clipboard that treats credentials like credentials.
Detection + redaction
Credentials, tokens and keys are recognized on-device and masked in the UI the moment they're captured.
Auto-expiry (TTL)
Detected secrets can auto-expire out of history, so a copied key doesn't linger for weeks.
Clipboard auto-clear
The system clipboard is cleared after a secret paste — the KeePassXC pattern — so it doesn't sit in the OS pasteboard.
Concealed paste-back
When Copywarden pastes a secret it tags the write org.nspasteboard.ConcealedType, so well-behaved clipboard tools skip it and it stays off Universal Clipboard — a best-effort community convention, not a guarantee.
Honors upstream markers — always
Concealed and transient flags from other apps are honored unconditionally — hard-coded, not a setting. A user-editable per-app exclusion list ships pre-seeded with 1Password, Bitwarden, LastPass and Keychain Access, and Copywarden re-marks its own secret paste-backs as concealed so other clipboard managers can't capture them.
An agent can use your clipboard. What it sees is always redacted.
App Intents, Shortcuts and Spotlight route through a single security chokepoint, AgentAccessGuard, which redacts every result an agent sees (unconditional, no override), honors a kill-switch (Local-Only mode — or an admin policy, MDM support rolling out — disables agent access entirely, before any data is read), and audit-logs every access to a tamper-evident log — which tool, when, how many items, how many secrets withheld — never the content itself. An MCP server is in development behind the same guard. It is the opposite of clipboard-to-cloud "AI memory."
Threat monitoring & screen safety
Copywarden detects debugger attachment, active recordings and screen shares, and redacts your history and detected secrets while one is live. Detecting an active video-call share (Zoom, Teams, Webex, Meet) uses the optional Screen Recording permission; without it, Copywarden still detects system capture and common recorder apps. We don't claim invisibility — previews stay blurred until you authenticate, so a captured screen shows nothing useful.
Sync & data residency
Local-first by design: everything works with sync off, and nothing leaves your Mac unless you opt in. Encrypted sync — Copywarden Account, self-hosted WebDAV, and on-network peer-to-peer — is in development, all carrying the same encrypted envelope, with end-to-end encrypted iCloud sync planned. Local-Only mode refuses all cloud and off-device transports for air-gapped, HIPAA, or ITAR environments.
Auditability
A tamper-evident, HMAC-chained audit log records access events — never content — and exports to JSON or CSV for your compliance review.
We'd rather under-promise than overstate.
Copywarden ships GDPR, HIPAA and Banking modes that enforce stricter content-retention caps (GDPR/HIPAA 7 days, Banking 3 days) and tag items for classification and audit context. Per-mode access-control and session enforcement are not yet wired — so we market only what we can currently prove: encrypted, on-device, offline, audit-logged. These are configurable controls and profiles, not a certification.
Formal, independent attestations are planned, not claimed: an external security review is being scoped, and SOC 2 is on our roadmap — we will pursue a Type II attestation when our enterprise customers require it, and we will not claim it until the report is issued. A BAA template is available for legal review; we don't sign BAAs for cloud-sync deployments today.
What we don't protect against
Honest threat models have edges. Copywarden protects your clipboard history against disk theft, at-rest reading by other apps, screen-share exposure, and agent over-reach. It cannot protect against malware running as your user while the app is unlocked, or a kernel-level keylogger — nothing in userspace can. And plainly: no independent audit yet, no bug bounty yet, sync not yet shipped.
Found something? We offer safe harbor.
We welcome good-faith security research. Contact details and scope live in our machine-readable /.well-known/security.txt (RFC 9116). Reports go to security@copywarden.com; our disclosure policy commits to a single, complete public notice — never a drip.