# BTC↔XMR atomic swaps: eigenwallet vs BasicSwap vs Farcaster (2026) > Compare eigenwallet, BasicSwap, and Farcaster for BTC↔XMR atomic swaps—setup cost, custody model, Tor, and when to prefer them over instant aggregators. Markdown twin of https://xmr.club/guides/btc-xmr-atomic-stack-eigenwallet-basicswap-farcaster. CC-BY-4.0. Attribute "xmr.club". ## At a glance - Canonical: https://xmr.club/guides/btc-xmr-atomic-stack-eigenwallet-basicswap-farcaster - Slug: btc-xmr-atomic-stack-eigenwallet-basicswap-farcaster - Title: BTC↔XMR atomic swaps: eigenwallet vs BasicSwap vs Farcaster (2026) - Description: Compare eigenwallet, BasicSwap, and Farcaster for BTC↔XMR atomic swaps—setup cost, custody model, Tor, and when to prefer them over instant aggregators. - Published: 2026-09-09 - Last reviewed: 2026-09-09 ## Intro Atomic swaps represent the cryptographic holy grail of cryptocurrency exchange: moving between Bitcoin and Monero with zero central custody, zero accounts, and zero possibility of mid-flight AML freezes. But 'atomic' does not mean 'frictionless' or 'bug-free.' Here is an honest audit of the current atomic stack. ## Body ## Atomic vs Instant vs P2P: Three trust models When moving capital from Bitcoin into Monero without submitting government identity documents, you must choose between three fundamentally different technical models: ``` [ Comparing Trust Architectures ] 1. INSTANT SWAP AGGREGATORS (kyc.rip, Trocador, FixedFloat) [You] ──(BTC)──> [Custodial Desk] ──(XMR)──> [You] • Speed: Minutes • Friction: Low (Web browser) • Counterparty Risk: High during custody window; automated AML freezes possible 2. DECENTRALIZED P2P NETWORKS (Haveno, RetoSwap, Bisq) [Buyer] <──(2-of-3 Multisig Escrow)──> [Seller] ^ | (Arbitrator in dispute) • Speed: 30–60 minutes (or days for cash by mail) • Friction: Medium (Desktop client, security deposit) • Counterparty Risk: Cryptographic escrow; relies on human arbitration for disputes 3. CROSS-CHAIN ATOMIC SWAPS (BasicSwap, eigenwallet, Farcaster) [Bitcoin Blockchain] <══(Adaptor Signatures)══> [Monero Blockchain] • Speed: 30–120 minutes (block confirmations on both chains) • Friction: High (Local daemons or desktop clients) • Counterparty Risk: MATHEMATICALLY ZERO (Code-enforced atomicity; no third party) ``` In an instant swap, you give a centralized exchange temporary custody of your Bitcoin. If their compliance engine flags your UTXO, they freeze your funds. In a P2P DEX like [Haveno](/exchanges/haveno), coins are held in on-chain multi-signature escrow, and an appointed arbitrator resolves disputes. In an **atomic swap**, there is no intermediary desk, no escrow deposit, and no arbitrator. The exchange of value is governed strictly by mathematics. Through the use of Hash Time-Locked Contracts (HTLCs) and cryptographic adaptor signatures, the transaction is **atomic**: either both parties receive their respective assets, or the protocol aborts and both parties receive their original funds back automatically. --- ## How BTC↔XMR atomic swaps actually work Implementing an atomic swap between Bitcoin and Monero was long considered one of the hardest cryptographic challenges in crypto. Bitcoin possesses a rich scripting language (`Script`) that natively supports hash locks and relative timelocks (`OP_CHECKLOCKTIMEVERIFY`). Monero, by deliberate design, has no scripting language whatsoever—its blockchain enforces privacy via stealth addresses, RingCT, and ring signatures. To execute a swap without Monero smart contracts, the privacy research community pioneered the use of **Schnorr / ECDSA adaptor signatures** and verifiable discrete logarithm equality proofs (DLEQ): 1. **Locking Bitcoin:** The buyer locks Bitcoin into a 2-of-2 multisig output on the Bitcoin blockchain governed by a time lock. 2. **Locking Monero:** The seller locks Monero into a freshly generated Monero output where the spend key is split into two halves. 3. **The Cryptographic Handshake:** When the buyer signs the Bitcoin transaction to claim the funds, the mathematical signature necessarily reveals the missing secret key piece required for the other party to unlock the Monero output. 4. **Failure mode:** If either party goes offline or refuses to cooperate, the timelock expires on the Bitcoin chain, allowing the depositor to reclaim their BTC, while the Monero lock simply refunds to the maker. At no point can either party run away with both coins. --- ## The three primary atomic swap stacks The open-source ecosystem has converged on three distinct software architectures: ### 1. eigenwallet (formerly UnstoppableSwap) - **Architecture:** Desktop GUI application tailored for the **taker** (the person selling BTC to acquire XMR). - **Network transport:** 100% Tor hidden services. - **Node requirements:** Lightweight. The client utilizes public Bitcoin Electrum servers and public Monero daemon nodes, meaning you do not need to download entire gigabytes of blockchain history onto your local drive. - **Trade model:** The application connects to independent market makers running Automated Swap Backends (ASBs). The GUI displays available live swap offers with quoted rates and maximum trading limits. - **Strengths:** By far the lowest barrier to entry for end users. You download the desktop binary, launch it, fund the embedded Bitcoin wallet over Tor, paste your external Monero address, and click Swap. - **Weaknesses:** Historically directional (primarily optimized for BTC→XMR, with XMR→BTC capabilities being newer and having less market depth). Dependent on active ASB community operators maintaining liquidity. ### 2. [BasicSwap DEX](/mixers/basicswap) - **Architecture:** Full self-hosted decentralized exchange platform. - **Network transport:** Particl core secure messaging (SMSG) network over Tor. - **Supported assets:** Monero (XMR), Bitcoin (BTC), Litecoin (LTC), Particl (PART), Dash (DASH). - **Node requirements:** Heavy. In its primary self-hosted mode, BasicSwap runs full local nodes for the coins you trade (e.g. `bitcoind` and `monerod`), typically orchestrated via Docker containers. - **Strengths:** True peer-to-peer order book. Anyone can place limit maker orders or fill taker orders. It eliminates reliance on centralized quote servers or single ASB providers. Fully open-source and audited. - **Weaknesses:** Substantial hardware footprint. Requires hundreds of gigabytes of disk space and hours of initial blockchain synchronization before you can place your first trade. ### 3. Farcaster Protocol - **Architecture:** A modular, multi-repository Rust implementation of the cross-chain atomic swap specification. - **Network transport:** P2P gossip layer over Tor / I2P. - **Node requirements:** Modular daemons (`farcasterd`, `swapd`, `peerd`, `monero-wallet-rpc`). - **Strengths:** Highly modular, rigorous codebase written in memory-safe Rust. Serves as the protocol bedrock for modern developer integrations and headless terminal-based swapping engines. - **Weaknesses:** Primarily geared toward command-line power users, node operators, and third-party wallet developers building embedded swap frontends. --- ## Stack comparison matrix | Feature / Metric | [eigenwallet](https://eigenwallet.org) | [BasicSwap DEX](/mixers/basicswap) | Farcaster Protocol | | :--- | :--- | :--- | :--- | | **Primary Audience** | Desktop retail takers | Sovereign node operators & traders | Developers & advanced terminal users | | **User Interface** | Polished Desktop GUI | Web UI / Localhost Browser Dashboard | CLI & API daemons | | **Disk Space Needed** | < 1 GB (Remote Electrum/RPC) | 300 GB+ (Full local nodes) | Variable (Light or Full daemons) | | **Initial Sync Time** | < 2 minutes | Hours to days (chain sync) | Minutes to hours | | **Directionality** | BTC → XMR (Primary) | Multi-directional (BTC, XMR, LTC) | Bi-directional (BTC ↔ XMR) | | **Tor Support** | Built-in native Tor | Built-in Tor / Particl SMSG | Built-in Tor daemon support | | **xmr.club Listing** | Tracked in Guides | mixers · **Grade A** | Tracked in Tools | --- ## Incident & patch literacy: Understanding code risk In centralized finance, risk comes from corrupt humans. In atomic swaps, risk comes from **cryptographic implementation bugs and timing race conditions**. Privacy users must approach atomic tools with mature incident literacy: ### The Automated Swap Backend (ASB) vulnerability cycle In late 2024 and early 2025, security audits of early UnstoppableSwap ASB implementations uncovered edge-case transaction replay risks where an aggressive attacker could manipulate Bitcoin mempool feerates to delay a refund transaction past the lock expiration window. - **The response:** The developers immediately published responsible disclosure notices, advised ASB operators to suspend automated order fills, and re-engineered the refund timelock buffer formulas before rebranding as **eigenwallet**. - **The takeaway:** As a **taker** (sending BTC to receive XMR), your capital is heavily protected because you are the one redeeming the Monero output. As a **maker** (running an automated server providing liquidity), you are exposed to script vulnerabilities, mempool reorgs, and software crashes. If you run a maker node, you must track upstream project repositories and apply updates immediately. ### Responsible disclosure as a trust signal At xmr.club, we do not downgrade projects simply because a vulnerability was discovered. Software of this cryptographic complexity will inevitably have edge cases. We evaluate operators and open-source teams on **how they handle disclosure**: - Did they notify users before a public exploit occurred? - Were patches shipped transparently with open commit histories? - Did they avoid deceptive marketing claims like "100% mathematically unhackable"? Both BasicSwap and eigenwallet have demonstrated exceptional maturity in addressing technical flaws responsibly. --- ## Practical playbook: Executing your first atomic swap If you are executing your first BTC→XMR atomic swap, follow this operational checklist: ### Step 1: Verify package integrity Download the software exclusively from official repositories (e.g. `eigenwallet.org` or `basicswapdex.com`). Always verify the developer's PGP cryptographic signature against the downloaded release binary before execution. Never run an unsigned binary downloaded from a search engine ad or third-party forum. ### Step 2: Ensure persistent network connectivity An atomic swap is an interactive protocol. While an instant swap allows you to send coins and close your browser, an atomic swap requires your local client to monitor the Bitcoin and Monero blockchains, exchange cryptographic keys at specific confirmation heights, and broadcast the final claim transaction. - **Do not close your laptop.** - **Do not put your computer to sleep.** - **Ensure an uninterrupted internet connection** until the status screen confirms that the Monero has been credited to your local wallet. ### Step 3: Start with a pilot micro-swap Never execute a $5,000 swap on your initial run. Execute a small test transaction ($50 to $100) first. This allows you to verify that your Tor connection is stable, understand the time delay associated with Bitcoin block confirmations, and verify that your Monero wallet syncs the incoming balance correctly. --- ## When NOT to use atomic swaps Atomic swaps are the gold standard for sovereign privacy, but they are not always the rational choice: 1. **You are in a hurry:** An atomic swap takes anywhere from 30 minutes to 2 hours because both blockchains require multiple irreversible on-chain confirmations before releasing cryptographic secrets. If you need instantaneous execution within 5 minutes, an instant aggregator such as [Trocador](/exchanges/trocador) or [kyc.rip](/exchanges/kyc-rip-aggregator) is vastly faster — at the cost of custodial and backend risk during the swap window. 2. **You are swapping small balances (< $50):** Because an atomic swap requires multiple on-chain Bitcoin transactions (funding the multisig, broadcasting the claim, and potentially processing refunds), high Bitcoin network miner fees can eat a significant percentage of your trade. 3. **You have zero technical tolerance:** If downloading desktop software, waiting for block confirmations, and managing local wallet backups feels overwhelming, decentralized P2P ([RetoSwap](/exchanges/retoswap)) or vetted instant desks provide a gentler learning curve. --- ## Frequently Asked Questions ### Can an atomic swap freeze my Bitcoin for AML checks? No. An atomic swap is an open-source peer-to-peer cryptographic protocol. There is no centralized compliance server, no third-party custody, and no API endpoint connected to chain-analysis surveillance engines. Neither party has the technical capability to freeze funds or demand identity documentation. ### What happens if the other person's computer disconnects during a swap? The protocol contains built-in cryptographic refund safety nets. If the counterparty goes offline or fails to broadcast their transaction before the pre-agreed time lock expires, your client automatically broadcasts a refund transaction that returns your original deposit back to your wallet. You lose only the on-chain miner transaction fees. ### Does an atomic swap break the on-chain link completely? Yes. On the Bitcoin blockchain, observers only see an unexceptional 2-of-2 multisig spend. On the Monero blockchain, your funds arrive in a native Monero output protected by stealth addresses and RingCT. There is zero cryptographic or deterministic on-chain link connecting the Bitcoin input to the resulting Monero balance. ## Picks - [BasicSwap DEX](https://xmr.club/mixers/basicswap) — Grade A open-source cross-chain DEX. Uses adaptor signatures over Tor without bridge tokens, wrapped assets, or centralized coordinators. - [Haveno](https://xmr.club/exchanges/haveno) — Grade A decentralized P2P network. Ideal companion route when atomic swap order book depth is insufficient for large volume. - [kyc.rip](https://xmr.club/exchanges/kyc-rip-aggregator) — Grade B first-party aggregator (conflict disclosed). A pragmatic fallback when speed and rate matter more than running local node infrastructure. ## How to cite Source: xmr.club, "BTC↔XMR atomic swaps: eigenwallet vs BasicSwap vs Farcaster (2026)". https://xmr.club/guides/btc-xmr-atomic-stack-eigenwallet-basicswap-farcaster (CC-BY-4.0). ## Related - https://xmr.club/guides — full guides index (59 guides) - https://xmr.club/methodology — how the directory grades providers referenced in this guide - https://xmr.club/transparency — funding model + editorial firewall - https://xmr.club/data.json — full provider dataset (CC-BY-4.0) ## License CC-BY-4.0. Attribute "xmr.club".