How Monipay Works , Wallet, Gasless Relayer, Fee Model

How it works

Monipay is a non-custodial wallet with a convenience layer for gasless payments and username resolution.

The Invisible Wallet

When you sign up, Monipay generates a standard private key locally on your device (browser localStorage or mobile Secure Enclave).

• Encryption: Your key is encrypted with AES-256-GCM using a key derived from your 6-digit PIN.
• Custody: Monipay never sees your private key or your PIN. The encrypted blob is backed up to your Google Drive (optional) so you can recover it on other devices.
• Standard Curve: We use secp256k1 for EVM chains (Base, BSC, Tempo, Celo) and Ed25519 for Solana. You can export your key at any time and use it in MetaMask or Phantom.

Gasless sponsorship

You do not need ETH, BNB, or SOL to pay for gas. Monipay uses three distinct sponsorship models:

• Base & BSC: We use ERC-2771 meta-transactions. You sign a message (EIP-712), and our relayer pays the gas to execute it on-chain.
• Solana: We use a feePayer relay. You sign the transaction, and our relayer adds a second signature as the fee payer before broadcasting.
• Tempo: We use native fee sponsorship (EIP-2718 type 0x76). The transaction includes a feePayer field, and the sponsor's signature is included in the payload.

Cross-chain routing

Your MoniTag is your identity across all chains. When you send a payment:

1. Monipay checks if the recipient is on the same chain → direct send.
2. If not → automatic cross-chain routing (currently same-chain only; cross-chain bridge planned).
3. If the sender's preferred chain has zero balance → app suggests funding or switching.

Fee model

• User fee: 0 , gas is fully sponsored.
• Platform fee: 1% of every payment, deducted atomically by the smart contract.
  • For social payments (MoniBot), the fee is on top of the user-typed amount. The recipient gets the full amount; the sender pays amount + 1%.
  • For direct app payments, recipient gets full amount; platform fee comes from the same transfer via the contract split.
• MoniBot fees also apply when a sponsored account uses gas grants.

Database & state

Monipay uses Supabase (Lovable Cloud) for:

• Profiles, MoniTag registry, social identity links
• Transaction history (receipts) , on-chain hash is canonical
• Merchant orders, products, customers
• Edge functions for the relayer, MoniBot worker, webhook signing

The blockchain remains the source of truth for funds. The database is for UX (history, names, receipts).

Read next

• Smart contracts & ABIs
• Security model
• Supported chains