Portal to Bitcoin Mainnet: Atomic Swaps That Slash Lightning Fees 90%

Title: Portal to Bitcoin Mainnet: Atomic Swaps That Slash Lightning Fees 90%

Introduction Bitcoin’s emergence as the global settlement layer has long been constrained by bridge-based interoperability and opaque Lightning routing fees (currently ~1 sat per payment). Portal to Bitcoin (PTB) solves both challenges. Launched on October 13, 2025 with $92 million in backing from Paloma Investments and others, PTB offers trust-minimized, HTLC-based atomic swaps between BTC and assets on Ethereum, Solana, and more. Through its BitScaler multi-party channel factories, PTB cuts per-transaction fees by up to 90 %, from ~1 satoshi to ~0.1 satoshi, while remaining near-instantaneous.

1. How PTB Works At its core, PTB leverages classic Hashed Timelock Contracts extended with Multi-Party Channel factories (MPCh) and Non-Custodial Signing Delegation. A swap locks BTC on one chain and a matching asset on another under the same hash and staggered timelocks. Revealing the preimage atomically settles both sides; if the swap fails, funds refund automatically. BitScaler consolidates channel openings into a single on-chain transaction, sharing parameters across LPs and delegating signing without surrendering UTXOs. This design requires no new Bitcoin opcodes and supports advanced constructs—Discreet Log Contracts, oracles, and Merkle-tree DeFi—while settling on Bitcoin’s base layer.

2. Fee Comparison Lightning’s median fee today is ~0.000001 BTC (1 sat), with peaks at 500 ppm. PTB’s BitScaler dynamic routing averages 0.0000001 BTC (0.1 sat)—a 90 % reduction—while completing end-to-end swaps in under five seconds and eliminating channel rebalancing overhead.

3. Swap SDK Integration Developers can integrate the @portaldefi/swap-sdk via npm to power cross-chain swaps in minutes. Key functions include fetching quotes, building and signing transactions, and monitoring status—all without bridges or custodians:

import { PortalSwap } from '@portaldefi/swap-sdk';
const portal = new PortalSwap({ rpcProviders: {/* btc, eth, sol endpoints */} });
const quote = await portal.fetchQuote({ fromChain:'btc', toChain:'eth', fromAmount:100000 });
const swapTx = await portal.executeSwap(quote, userPrivateKey);
console.log('Swap hash:', swapTx.hash);

This plug-and-play SDK preserves self-custody and taps into Bitcoin’s $1 trillion liquidity pool.

4. Token & Arbitrage Opportunities PTB’s native token ($PTB) underpins governance and liquidity incentives. Listed on Binance, Bitget, and KuCoin, its price diverged by up to 3 % in week one. Traders can automate a cycle—buy $PTB on a lower-priced exchange, withdraw BTC via a PTB swap (0.3 % fee), deposit BTC on the higher-priced exchange, and convert back to USDT—capturing net profit within 10 minutes.

5. Security Considerations HTLCs protect atomicity but can be griefed by malicious parties, locking liquidity until timeouts and incurring refund fees. Liquidity exhaustion occurs if LPs mass-withdraw. PTB mitigates these via staggered commitments, on-chain insurance collateral, and real-time monitoring.

6. Roadmap Upcoming features include native BTC↔SOL swaps, the RAFA AI wallet assistant, and $10–50 million additional liquidity. Q4 2025 will bring mobile SDKs and institutional APIs powered by Enclave MPC for sub-second signing and policy controls.

Conclusion Portal to Bitcoin unites HTLC atomic swaps with BitScaler’s channel factories to deliver near-instant, 90 % cheaper cross-chain settlement without custodial risk. Builders gain seamless SDK integration, traders unlock time-sensitive arbitrage, and institutions will soon benefit from mobile and API toolkits. As PTB evolves, it stands to cement Bitcoin’s role as the universal DeFi settlement layer.