Secure payments for humans and AI agents across the Stellar XMSS economy
// nebula: execute an XMSS-secured transfer
await nebula.sendSecure({
to: "GABCD...WXYZ",
asset: "USDC",
amount: "2",
signatureScheme: "XMSS",
});Powered by Soroban + XMSS
& Post-Quantum Crypto
XMSS-ready Stellar wallet with built-in DEX
Nebula Core is your gateway to Stellar. Manage multiple accounts, send payments, and swap tokens through our DEX aggregator that finds the best rates across Stellar SDEX. A streamlined signing flow and secure approvals make advanced on-chain actions feel simple for both users and automation.
XMSS signatures with ZK-SNARK verification
Your Ed25519 key is permanently disabled (masterWeight=0). Instead, transactions are signed locally with XMSS for hash-based post-quantum protection. A ZK proof verifies your signature on-chain without revealing it. No private key to steal, no quantum vulnerability to exploit.
Visual automation for trading and payments
Drag-and-drop workflow designer for AI agents and automated strategies. Set price triggers, define swap actions, and chain conditions — no coding required. Built-in spending limits, domain whitelists, and per-agent budgets keep your funds safe while agents work autonomously.
Smart contract verification on Stellar
Our Soroban smart contract acts as the transaction gatekeeper. It verifies ZK proofs, stores pending approvals, and authorizes payments — all without holding any private keys. The relayer only pays gas fees and never has custody of your funds. True non-custodial security.
Nebula Wallet is a quantum-safe Chrome extension wallet for the Stellar blockchain. It combines post-quantum cryptography (XMSS), zero-knowledge proofs, and secure agent automation to provide future-proof security against quantum computer attacks.
Traditional wallets use Ed25519 signatures which are vulnerable to quantum computers running Shor's algorithm. Nebula disables your Ed25519 key entirely and instead uses XMSS (a hash-based post-quantum signature scheme) combined with ZK-SNARKs to authorize transactions through a smart contract. This means even if quantum computers break Ed25519, your funds remain secure.
XMSS is a practical hash-based signature approach designed for post-quantum security. It avoids the assumptions used by classical public-key systems and gives Nebula a clear path for long-term key protection while keeping signing logic deterministic and verifiable.
The Agent Builder is a visual drag-and-drop workflow designer that lets you automate trading and payments without coding. You can create triggers (price thresholds, time-based), set conditions, and execute actions (swaps, transfers). Agents have built-in spending limits and domain whitelisting for security.
Nebula is built on Stellar and Soroban (Stellar's smart contract platform). We chose Stellar for its fast finality (3-5 seconds), low fees, and built-in DEX. The quantum-safe verification happens through a Soroban smart contract that validates ZK proofs of your XMSS signatures.
Yes, and here's why: Your original Ed25519 key is permanently disabled (masterWeight=0) so it cannot sign transactions. Your XMSS key signs locally, and a ZK proof is generated to verify the signature without revealing it. The relayer only pays gas fees and never has custody of your funds. There's no private key that can be stolen to drain your wallet.
Yes! Nebula includes a built-in DEX aggregator that fetches quotes from multiple sources including Stellar's native SDEX orderbook. It finds the best route, calculates price impact, handles slippage, and automatically creates trustlines for new assets. You can swap any Stellar token with just a few clicks.
Download the Chrome extension from our GitHub repository, create a new wallet or import an existing Stellar account, and you're ready to go. For quantum-safe mode, you'll need to register your XMSS public key with our verification contract. Check out the README for detailed setup instructions.
© 2025 Nebula. Powered by XMSS + Stellar.