Take Control of Your Digital Payments

UmbraPayOS offers a seamless, private tap-to-pay experience for Web3. Offline ZK-NFC transactions, x402-backed finality, optimized fees. Private Tap-to-Pay Protocol for Web3 Payments. Accept, log, and verify x402 payments autonomously via UmbraPayOS.

x402 Payments

Receiver online
TTL 90s
Anti-replay active
Name
UmbraPayOS
Ticker
$UMB
Chain
BSC
402→ Payment Required → wallet pays → signed receipt →x402verifies → feature unlocked
curl https://api.umbrapay.os/v1/resource -H "accept: application/json"
↳ returns HTTP 402 + pay_url ⋅ submit receipt to finality
UmbraPayOS

Reimagining the Act of Payment

UmbraPayOS isn't just another payment protocol — it's a redefinition of what payment means in the era of decentralization.

Tap to pay—offline.

Tap their phones together to send crypto privately, even with no signal or connection.

Shop without exposure.

Purchase items in stores without revealing wallets or personal data.

Autonomous devices.

Enable vending machines and IoT devices to autonomously accept crypto offline.

Inclusive commerce.

Empower small businesses and communities in low-connectivity regions to participate in the Web3 economy.

UmbraPayOS

The Power Behind UMB

At the heart of UmbraPayOS lies a stack of revolutionary technologies, working together seamlessly.

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ZK-NFC Wallets

The first of their kind. Use Zero-Knowledge Proofs to exchange ephemeral payment confirmations instead of revealing public addresses—keeping transactions private, unlinkable, and untraceable.

x402 Authentication Layer

Bridges offline transactions with on-chain finality. When devices reconnect, they securely synchronize and validate stored payments through zk-reconciliation.

AI Risk Filter

On-device intelligence detects anomalies, prevents double-spending, and boosts transactional trust—without sending data to any centralized server.

Offline-First OS Architecture

Engineered to operate independently of the internet—resilient in remote regions, disaster zones, and developing economies where connectivity is unreliable.

UmbraPayOS

ZK-NFC Wallets

Tap-to-Pay Without a Trace

At the heart of UmbraPayOS lies the ZK-NFC Wallet, a breakthrough in how devices communicate and transact. When two users—or a user and a merchant—bring their devices close, UmbraPayOS establishes a zero-knowledge handshake via NFC. ephemeral cryptographic proofs.

How the ZK-NFC handshake works

1.
Tap — devices initiate NFC session
2.
Prove — local ZK proof of balance & legitimacy
3.
Store — ephemeral receipt cached offline
4.
Sync — later posted via x402 for finality
UmbraPayOS

x402 Payment Layer

Offline Transactions, Online Finality

One of UmbraPayOS's greatest innovations is the x402 Authentication Layer — the protocol that bridges offline payments with on-chain settlement. Most blockchains demand constant connectivity; UmbraPayOS breaks this dependency with a deferred settlement model.

How x402 works (deferred)

  • •
    Offline pay: the transaction is cryptographically signed and stored as a pending payment proof.
  • •
    Each proof is bound to a unique x402 token representing its pending settlement state.
  • •
    When either device reconnects, the x402 tokens submit to validator nodes for zk-reconciliation.
GET /resource → HTTP 402 Payment Required
POST /x402/submit { receipt, token }
→ verify zk-proof → finality on-chain
Offline Device
x402 Reconciliation
On-chain Finality
Hover / tap the flow to send pending proofs.

Protocol properties

ConnectivityOffline-first
Securityzk-proof + anti-replay
StateDeferred settlement
Identifier leaksZero
ReconcileOn reconnect
Interface402 + /submit
UmbraPayOS

Frequently Asked Questions

Everything you need to know about UmbraPayOS, ZK-NFC, and the x402 layer.

UmbraPayOS is a private tap-to-pay OS for Web3. It lets phones and small terminals exchange zero-knowledge payment proofs offline, then settle on-chain later via the x402 layer.
Traditional flows expose addresses or broadcast a public transaction. ZK-NFC exchanges an ephemeral proof of legitimacy/balance—not the address—so payments remain private, unlinkable, and untraceable.
The proof is stored locally as a pending payment and bound to a unique x402 token. When either device reconnects, x402 performs zk-reconciliation and posts finality on-chain.
UmbraPayOS is designed to be chain-agnostic. Integrations prioritize modern, fast-finality networks. Support lists are modular and can be extended per deployment.
Offline, the proof includes a fee intent. On reconnection, x402 reconciles and submits the settlement with the appropriate network fee policy for the chosen chain.
Keys stay under the owners control (OS-level secure enclave where available). You can revoke a device and restore access via your seed/backup—pending proofs remain verifiable.
No PII is required for core payments. UmbraPayOS focuses on privacy-preserving proofs. Merchant-side compliance (if any) can be layered separately per jurisdiction.
Each proof includes anti-replay guards (nonce/TTL) + the on-device AI Risk Filter. On reconnect, x402 rejects conflicting proofs during zk-reconciliation.