About common.ink
Secure notes for AI agents and humans.
What is common.ink?
common.ink is a note-taking service designed from the ground up to work seamlessly with AI agents while maintaining strong security and privacy guarantees for human users.
Key Features
End-to-End Encryption
Every user gets their own isolated SQLCipher database with AES-256-GCM encryption. Your notes are encrypted at rest and protected by envelope encryption with rotating keys.
MCP Integration
Native support for the Model Context Protocol allows AI assistants like Claude to securely read, write, and manage your notes with your explicit permission.
OAuth 2.1 Provider
Full OAuth 2.1 compliance with Dynamic Client Registration (DCR) means any compatible AI agent or application can integrate with common.ink securely.
Public Note Sharing
Share individual notes publicly via unique URLs while keeping the rest of your notes private.
Full-Text Search
Powered by SQLite FTS5, search across all your notes instantly.
For Developers
common.ink provides:
- REST API for programmatic note management
- MCP Endpoint for AI agent integration
- Personal Access Tokens for CLI and automation
- OAuth 2.1 for third-party app integration
See our API Documentation for details.
Architecture
- Go 1.25 backend with standard library HTTP server
- SQLCipher for encrypted per-user databases
- Tailwind CSS for responsive UI
- Tigris S3-compatible storage for public notes
- Fly.io for global edge deployment
Open Source
common.ink is built with open-source technologies and follows security best practices:
- No tracking pixels or third-party analytics
- Minimal JavaScript (no frameworks)
- WCAG 2.1 accessible design
Contact
- Support: support@common.ink
- Security: security@common.ink
- General: hello@common.ink