stroemnet

! UNAUDITED: COMPLETELY EXPERIMENTAL. DO NOT USE IN PRODUCTION. ! This code has not been security-audited and is under active development. It may contain bugs that lead to loss of funds. Use at your own risk on testnets only.

A trustless cross-chain atomic swap protocol. This project is a P2P system where different actors interact and form an RFQ-based system. Users can request quotes and market makers compete in fulfilling them in a transparent and verifiable manner. Finally the cross-chain swap requests are fulfilled based on trustless HTLC contracts.

Roles

Stroemnet has two kinds of participant, split by where they run:

• Native daemon (stroemnetd): runs as an LP (liquidity provider, answers quote requests and settles swaps) or as an observer / CCR relay (tracks and helps settle swaps without quoting). Built from crates/node.
• WebAssembly SDK (StroemGateway): the taker. Compiled from crates/wasm and consumed from TypeScript/JavaScript in the browser. The taker requests quotes and submits commitments.

Supported channels

TOML key / SDK name	ChannelId byte	Token	Kind
kaspa-tn10	0	KAS	Kaspa (UTXO)
ethereum-sepolia	1	ETH	EVM
igra-galleon	2	iKAS	EVM

---

Running the daemon (stroemnetd)

The daemon reads all of its configuration from a single TOML file (globals, per-channel settings, and private keys). The file path is the first positional argument and defaults to stroemnet.toml in the working directory.

# Debug
cargo run -p stroemnet-node --bin stroemnetd -- ./stroemnet.toml

# Release
cargo build --release -p stroemnet-node --bin stroemnetd
./target/release/stroemnetd ./stroemnet.toml   # arg optional -> defaults to ./stroemnet.toml

The config file holds private keys. Protect it with file permissions (e.g. chmod 600 stroemnet.toml).

LP node

An LP answers incoming quote requests and signs proposals. Set lp = true and provide a private_key for every configured channel (the daemon refuses to start otherwise).

lp = true

[channels.ethereum-sepolia]
private_key = "0x<sepolia-key>"
rpc_url = "https://eth-sepolia.api.onfinality.io/public"
htlc_address = "0xb249849CAc76bcd86A566016AcA5e7FC63dA5122"

[channels.kaspa-tn10]
private_key = "<kaspa-key-hex>"
network_id = "testnet-10"

Observer

An observer does not answer quote requests. It tracks swaps on the network and relays peer-to-peer messages (reveals, script announcements). Set lp = false or simply omit lp (the default).

Competitive Claim Rescue (CCR) is configured per channel with participate_ccr (default false):

• Observer with CCR (participate_ccr = true) — in addition to tracking, the node helps settle swaps it observes by submitting claim and refund transactions on-chain. Actually broadcasting those transactions requires a funded private_key for that channel; without a key the node still tracks but cannot submit.
• Observer without CCR (participate_ccr = false) — purely passive. The node observes and relays but never submits any chain transactions for that channel.

# Observer that actively settles (CCR on) on EVM, passive on Kaspa.
lp = false

[channels.ethereum-sepolia]
participate_ccr = true
private_key = "0x<sepolia-key>"   # needed to broadcast settlement txs
rpc_url = "https://eth-sepolia.api.onfinality.io/public"
htlc_address = "0xb249849CAc76bcd86A566016AcA5e7FC63dA5122"

[channels.kaspa-tn10]
participate_ccr = false
network_id = "testnet-10"

---

Configuration file (stroemnet.toml)

Full annotated example with every key. Required globals have no default; a missing one is a clear parse error. Channel tables: the table being present enables that channel.

# Globals 
bind_addr = "0.0.0.0:9000" # IPv4 socket to listen on (required)
external_hostname = "wss://your-host.example/"  # how peers reach you (required)
min_trade_usd = 1.0 # reject trades below this (LP only; required when lp = true)
max_trade_usd = 100000.0 # reject trades above this (LP only; required when lp = true)
spread_percent = 0.5 # LP spread, in percent (LP only; required when lp = true)
price_oracle_update_interval_secs = 60 # price refresh cadence (required)

commit_buffer_secs = 960 # optional, default 960 — propagation buffer. added when computing user unlock timestamps
bootstrap_peers = ["wss://a-known-node.example/"]  #optional, default []
lp = false # optional, default false (observer)
peer_db = "./stroemnet-peers.db" # optional, default "./stroemnet-peers.db"

[channels.kaspa-tn10]
private_key = "<kaspa-key-hex>" # required when lp = true; optional for observers
participate_ccr = true # optional, default false
network_id = "testnet-10" # required for Kaspa channels
wrpc_url = "wss://<kaspa-wrpc-node>" # optional — omit to use a public resolver
coinbase_maturity = 100 # optional
script_ttl_secs = 14400 # optional — how long monitored redeem scripts live
min_confirmations = 30 # optional — finality threshold

[channels.ethereum-sepolia]
private_key = "0x<sepolia-key>" # required when lp = true; optional for observers
participate_ccr = true # optional, default false
rpc_url = "https://eth-sepolia.api.onfinality.io/public" # required for EVM channels
htlc_address = "0xb249849CAc76bcd86A566016AcA5e7FC63dA5122" # required for EVM channels
min_confirmations = 1 # optional — finality threshold

[channels.igra-galleon]
private_key = "0x<igra-key>"
participate_ccr = true
rpc_url = "https://galleon-testnet.igralabs.com:8545"
htlc_address = "0x<igra-htlc-address>"
min_confirmations = 1

Per-channel field applicability:

Field	Kaspa	EVM	Notes
private_key	x	x	required if lp = true; needed to submit CCR settlement txs
participate_ccr	x	x	default false
min_confirmations	x	x	finality threshold
network_id	x		required for Kaspa
wrpc_url	x		optional
coinbase_maturity	x		optional
script_ttl_secs	x		optional
rpc_url		x	required for EVM
htlc_address		x	required for EVM

---

WebAssembly SDK (TypeScript)

The taker runs in the browser via the crates/wasm package.

Build

Build with wasm-pack. Pick the target that matches your toolchain — web for native ES modules, bundler for webpack/vite/rollup, nodejs for Node:

wasm-pack build crates/wasm --target web --out-dir pkg

This emits crates/wasm/pkg/ containing stroemnet_wasm.js, the TypeScript definitions stroemnet_wasm.d.ts, and stroemnet_wasm_bg.wasm.

Minimal example

import init, {
  StroemGateway,
  getDefaultConfig,
  type CheckedQuote,
  type SwapStatusUpdate,
} from "./pkg/stroemnet_wasm.js";

await init(); // load the wasm module

// Start from the default config and tweak it.
const config = getDefaultConfig();
config.bootstrapPeers = ["wss://a-known-node.example/"];
// config.handler.spreadPercent = 0.5;  // optional tuning

const gateway = new StroemGateway(config);

// Subscribe before connecting — quotes/status arrive asynchronously.
gateway.onPeerCount((count: number) => console.log("peers:", count));
gateway.onQuote((quote: CheckedQuote) => {
  console.log("quote out:", quote.amount_out, "sig valid:", quote.signature_valid);
  // To accept: build a CommitmentV1 from the quote and call
  // await gateway.submitCommitment(commitment, secret);
});
gateway.onSwapStatus((update: SwapStatusUpdate) => {
  console.log("swap", update.swap_id, "stage:", update.stage);
});

await gateway.connect();

// Request a quote. origin/destination are ChannelId bytes:
//   0 = kaspa-tn10, 1 = ethereum-sepolia, 2 = igra-galleon
const swapId = crypto.getRandomValues(new Uint8Array(32));
await gateway.requestQuote(swapId, 1, 0, "0.05"); // 0.05 ETH (Sepolia) → KAS