SecretShields — Secret Shield for AI Chat

SecretShields is a local-first VS Code / Cursor extension that automatically masks secrets in your clipboard before you paste them anywhere — including AI chat windows, terminals, and pastebins.

How It Works

1. Copy text containing a secret (API key, token, DB URL, etc.)
2. SecretShields detects the secret within ~1 second (configurable via pollIntervalMs) and replaces your clipboard with a masked version
3. Paste anywhere safely — the secret is already masked
4. Restore (optional) — if you intentionally need the secret, restore it within a short time window. This triggers a rotation reminder.

Features

• Automatic clipboard masking — secrets are detected and masked within ~1 second of copying (polling-based, configurable)
• 39 detection patterns across 30+ platforms — AWS, GitHub, Stripe, OpenAI, Anthropic, Google, Vercel, Slack, SendGrid, Shopify, Twilio, DigitalOcean, npm, PyPI, HashiCorp Vault, Doppler, Linear, Grafana, New Relic, Heroku, PlanetScale, Docker Hub, Resend, Supabase, Netlify, Appwrite, Cloudflare, Discord, database URLs, SSH keys, JWTs, and more
• Low false-positive design — allowlist for known example values, Shannon entropy filtering, structural JWT validation, placeholder password detection for database URLs, template variable filtering, and per-pattern validation hooks
• Per-detector toggles — enable or disable detection for each platform individually via settings
• Restore with TTL — deliberately restore a masked secret for a short window (configurable, default 60s)
• Rotation reminders — restoring a secret starts a countdown; when it expires, you get a reminder to rotate with a direct link to the provider's rotation page
• Exposure log — track which secrets were exposed, when, and whether they've been rotated
• 100% local — no network calls, no telemetry, no data leaves your machine

Privacy Model

SecretShields is designed with privacy as a core feature:

• No network calls — detection, masking, and alerts are entirely local
• No raw secret persistence — raw secrets exist briefly in-memory only (for the restore TTL window); persistent storage holds only masked previews and metadata
• No telemetry — nothing is sent anywhere

Commands

Supported Platforms

Settings

Editor Paste Masking

In addition to clipboard masking, SecretShields can intercept paste operations in code editors:

• When you paste text containing secrets into a code editor, the paste widget offers a "Paste with SecretShields masking" option
• In offer mode (default): normal paste remains the default; masked paste is selectable from the paste widget
• In auto mode: SecretShields attempts to make masked paste the default (best-effort, depends on other paste providers)
• In off mode: SecretShields does not participate in editor paste at all

Configure via secretshields.editorPasteMasking.mode in settings.

Note: Editor paste masking works in code editor panes only. It does not apply to terminal, chat panels, or webview-based inputs.

Beta Notes

This is a public beta. Please help improve SecretShields:

• False positives (non-secrets getting masked): Open an issue with the masked text pattern (never include real secrets). We'll add it to the allowlist.
• False negatives (real secrets not detected): Open an issue describing the secret format (e.g., "Acme Corp API keys start with acme_"). We'll add a detection pattern.
• Temporarily disable: Set secretshields.enabled to false in VS Code settings, or click "Disable SecretShields" in the masking notification.
• Clipboard masking is polling-based — detection occurs within the configured pollIntervalMs (default 1000ms), not instantly on copy.

Limitations (MVP)

• SecretShields masks your clipboard proactively. It cannot intercept paste events inside Cursor or Copilot chat input fields directly (VS Code extensions cannot inject into other extensions' webviews).
• Editor paste masking is available for code editor panes only (TextDocuments), configurable via secretshields.editorPasteMasking.mode. It is optional and not relied on for core AI chat protection — clipboard-first masking remains the primary defense.
• Rotation is manual — SecretShields opens the provider's rotation page but does not auto-rotate credentials.

After Disabling or Uninstalling

• Previously-masked clipboard contents remain masked. SecretShields does not restore raw secrets when disabled or uninstalled — this is intentional. Restoring secrets on deactivation would be a security regression. If your clipboard contains masked text, simply copy any other text to overwrite it.
• Disable/uninstall may require a window reload to fully stop active clipboard monitoring in the current session. VS Code's extension host may continue running until you reload the window or restart the IDE.
• Other open windows matter. If you have multiple VS Code or Cursor windows open, any window with SecretShields still active can monitor the shared system clipboard.
• Cursor's own scrubber is independent. Cursor may have its own built-in heuristic that blocks secrets from being sent to AI providers. This is separate from SecretShields and will continue regardless of whether SecretShields is installed.

Installation

Install from the VS Code Marketplace or OpenVSX (for Cursor).

License

MIT