EUTXO.DEX

A decentralized exchange for the Ergo blockchain — red & black, non-custodial, built on the EUTXO model. Inspired by what ErgoDEX and spectrum.fi used to be.

Unofficial community project. Not affiliated with the Ergo Foundation. Not financial advice.

Run it

double-click serve.bat

That starts a zero-dependency PowerShell static server and opens the app at http://localhost:8080. (Any static server works: npx serve, VS Code Live Server, IIS…)

The app is plain ES modules — no build step, no npm, no backend. A static server is required because the WASM signing engine (sigma-rust) must be served with the correct MIME type.

What works today (verified)

Area	Status
Red/black EUTXO.DEX UI (Swap / Pools / Activity)	✅
Live chain data — height, protocol params, token registry, block activity	✅ from public API api.ergoplatform.com (CORS-open)
ERG/USD price (CoinGecko)	✅
Token discovery — real token ids/names/decimals from the chain	✅
AMM quotes — real constant-product math, BigInt-safe, fee + price impact + slippage	✅
Pools — create/remove/reset, reserves, TVL, swap log (persisted in localStorage)	✅ virtual liquidity (local settlement)
Wallet — create / import mnemonic (12/24) / import 32-byte seed, real sigma-rust key derivation	✅
Signing — sign_transaction, sign_message via sigma-rust WASM	✅ (engine loads via universal fetch+instantiate; local vendor dir or CDN fallback)
Real send (ERG + tokens)	✅ requires a reachable full node (Settings → Node URL), e.g. a node you run
Balances (unspent boxes)	✅ requires full node
Testnet faucet	✅ requires a testnet full node
Browser extension accounts (read-only)	best-effort, when window.ergo exists

Honest limitation: no public full node with the UTXO API is currently reachable, and on-chain AMM pool contracts are not deployed, so swaps settle on virtual (local) pools — the math is real, the settlement is simulated, and the UI labels it as such. Everything else (quotes, keys, signing, chain data) is real.

Architecture

eutxo-dex/
├── index.html          app shell (swap / pools / activity / modals / footer)
├── css/styles.css      red & black theme
├── js/
│   ├── config.js       networks, tokens, donations, fees, storage keys
│   ├── api.js          gateway (verified endpoints) + optional full-node client
│   ├── amm.js          constant-product pool engine (BigInt math) + persistence
│   ├── wallet.js       sigma-rust wallet: keys, address, sign tx/message
│   └── app.js          state, rendering, events, toasts, modals
├── vendor/ergo-lib/    ergo-lib-wasm-browser v0.28.0 (sigma-rust WASM, CC0)
├── assets/             logo + favicon (SVG)
├── tests/              verification suites (AMM math, wallet vectors, signed-tx proofs, engine self-check page)
├── package.json        test scripts (no runtime deps)
├── serve.ps1/.bat      zero-dependency Windows static server
└── README.md

Data sources (probed & verified 2026-08-21)

• GET https://api.ergoplatform.com/api/v1/info — height, protocol params
• GET https://api.ergoplatform.com/api/v1/tokens?limit=&offset= — token registry
• GET https://api.ergoplatform.com/api/v1/tokens/{id} — token details
• GET https://api.ergoplatform.com/api/v1/blocks?limit= — recent block list
• GET https://api.ergoplatform.com/api/v1/blocks/{id} — full block (txs + assets) → used to score active tokens
• https://api.coingecko.com/api/v3/simple/price?ids=ergo&vs_currencies=usd — ERG price
• Optional full node (your URL): /addresses/{a}/unspent, /blocks/tip, POST /transactions, POST /faucet

Wallet security model

• New wallet = 32 random bytes (CSPRNG crypto.getRandomValues) stored as the dlog secret — the same key type official Ergo keystores use.
• Import = 12/24-word mnemonic (BIP39 seed → HMAC-SHA512("Bitcoin seed") → sigma-rust master key, matching sigma-rust's own derivation) or a raw 32-byte seed.
• Keys stay in the browser. "Remember on this device" writes them to localStorage (visible to anyone with this browser) — the UI warns about that and offers a wipe.
• Signed transactions are built with sigma-rust in WASM and broadcast only to the node URL you configure.

Roadmap to full on-chain settlement

1. Compile a sigma-rs pool contract (deposit/withdraw/swap, LP mint/burn) → ergoTree.
2. Add DeployPool + Swap transaction builders in wallet.js (context extension, R-registers, pool box as input).
3. Point the swap button at real settlement when a pool contract exists on-chain; keep virtual pools as a zero-deployment demo mode.
4. Add 24h volume/fees from block scans for real pool TVL.

Credits

• sigma-rust / ergo-lib-wasm — ergoplatform/sigma-rust (CC0)
• Ergo node public API & explorer — ergoplatform
• Design: EUTXO.DEX