Account Abstraction & Paymasters
How Droplit provides ERC-4337-style account abstraction and paymaster functionality on Bitcoin.
Account Abstraction & Paymasters
Droplit provides the Bitcoin equivalent of Ethereum's ERC-4337 account abstraction stack. If you're building on BSV and need paymaster functionality, delegated transaction signing, or gasless user experiences — this is how it maps.
What is ERC-4337?
ERC-4337 introduced three concepts to Ethereum:
- Smart contract wallets — accounts governed by contract logic instead of a single private key
- Bundlers — services that batch user operations into on-chain transactions
- Paymasters — third parties that pay gas fees on behalf of users
These exist because Ethereum's externally owned accounts (EOAs) are rigid — you can't add custom validation, social recovery, or spending rules without moving to a contract wallet.
Why BSV doesn't need ERC-4337
Bitcoin's UTXO model and native script system already provide these capabilities:
| ERC-4337 | BSV Equivalent | How |
|---|---|---|
| Smart contract wallet | Bitcoin Script | Any spending condition expressible in script — multisig, time locks, hash locks — without a separate "account abstraction" layer |
| Bundler | Overlay network | The 1sat-stack overlay engine validates, indexes, and propagates transactions |
| Paymaster | Droplit | The /fund endpoint adds inputs to cover transaction fees — your app signs the logic, Droplit pays |
| UserOperation | CreateActionArgs | The BRC-100 wallet interface describes what you want; the wallet (or Droplit) figures out funding |
| EntryPoint contract | Protocol-level validation | Bitcoin miners validate scripts directly — no intermediary contract needed |
Droplit as a Paymaster
The /faucet/{name}/fund endpoint is a paymaster. Your application:
- Builds the transaction — constructs outputs with the business logic (identity records, token transfers, data attestations)
- Signs the critical parts — AIP signatures on BAP records, token authorization scripts
- Sends to Droplit — the fund endpoint adds UTXOs to cover fees and broadcasts
The user never needs BSV in their wallet. The application never needs to manage UTXOs. Droplit handles all of it.
┌─────────────┐ ┌──────────┐ ┌─────────────┐
│ Your App │────▶│ Droplit │────▶│ BSV Network │
│ │ │ Paymaster │ │ │
│ Build tx │ │ Add funds │ │ Validate & │
│ Sign logic │ │ Broadcast │ │ Confirm │
└─────────────┘ └──────────┘ └─────────────┘Compared to Ethereum Paymasters
| Feature | ERC-4337 Paymaster | Droplit |
|---|---|---|
| Fee currency | ETH (or ERC-20 via paymaster swap) | BSV (sub-cent transactions) |
| Integration | Deploy paymaster contract, register with EntryPoint | API call to /fund |
| Fee per transaction | $0.50 – $50+ (gas dependent) | < $0.01 |
| Verification | On-chain contract validation | BRC-77 signature verification |
| Bundling | Required (4337 bundler infrastructure) | Not needed (direct broadcast) |
| Setup complexity | Solidity contracts, bundler RPC, gas estimation | One API endpoint |
Use Cases
Gasless identity publishing — Users create a Bitcoin identity (BAP) without holding any BSV. The app builds and signs the identity record, Droplit funds and broadcasts it.
Agent-funded operations — AI agents perform on-chain actions (data attestation, token minting, profile updates) using Droplit as their funding source, without managing private keys for UTXOs.
Delegated transactions — A service builds complex multi-output transactions (token transfers, marketplace listings) and delegates funding to Droplit, keeping the signing authority separate from the funding source.
Free-tier applications — Apps offer free on-chain operations to users by funding transactions through their own Droplit instance, absorbing the sub-cent cost per transaction.
Getting Started
- Create a Droplit instance
- Fund it with BSV
- Use the Fund Transaction endpoint as your paymaster
- See Agent Playbooks for automation patterns
Related
- Fund Transaction Endpoint — API reference
- Permission Model — scope control for paymaster access
- Push Data Endpoint — simpler alternative when Droplit builds the entire transaction