Documentation

What is Harbor

Harbor is a developer-preview communication protocol built on Base. The current repository contains primitives and contracts, not a launch-ready messaging product.

Overview

Harbor is being built toward end-to-end encrypted messaging where you control your cryptographic keys. The current codebase can create a local web identity, encrypt identity backups, and interact with deployed Base Sepolia contracts, but the real contact, send, receive, decrypt, and message-persistence path is incomplete.

End-to-End Encrypted

The cryptographic primitives exist, but the integrated product messaging path is not launch-ready yet.

Self-Custodied

The web client stores identity keys locally. V1 backup and device enrollment can export encrypted identity material.

Built on Base

Base Sepolia contracts are deployed and tested. The web client still needs ABI and flow alignment.

How it Works

Harbor currently contains these implementation pieces:

  1. Identity Creation — When you start Harbor, cryptographic keys are generated locally on your device. These keys are linked to your Ethereum wallet address but are generated independently.
  2. Key Exchange — When you message someone, Harbor uses X25519 key exchange to establish a shared secret. The standalone primitives exist; the product contact-to-session flow is incomplete.
  3. Message Encryption — Each message is encrypted using XChaCha20-Poly1305 with keys derived from ratchet state. Current ratchet serialization has launch-blocking issues.
  4. Delivery — Encrypted messages are submitted to the Base blockchain. The recipient can identify and decrypt messages intended for them after the receive path is implemented.

What Makes Harbor Different

Most encrypted messaging apps require you to trust a company:

  • They store your messages on their servers
  • They manage your encryption keys (or key material)
  • They can lock you out of your account
  • They know who you're talking to and when

Harbor takes a different approach:

  • Messages are stored on-chain, not on company servers
  • You generate and control your own keys
  • No account to lock — your keys are your identity
  • Recipient privacy through cryptographic commitments

Getting Started

Head to the Quick Start guide to create a local identity and understand what is currently implemented.

Quick Start

Learn More