Xian DEX

xian-dex owns the DEX product: the canonical AMM contracts, the SnakX web frontend, and the hash-pinned contract bundle that downstream consumers deploy and verify against.

Contracts and frontend ship together as one tightly-coupled system. Operator automation that watches DEX events and reacts to them lives in xian-dex-automation, not in the product repo.

• Owning repo: xian-dex
• Contract bundle: xian-dex/contract-bundle.json
• Bootstrap script: xian-dex/scripts/bootstrap_dex.py
• Web app: SnakX (xian-dex/web/)
• Companion service: xian-dex-automation

Lifecycle

• Install phase: post-genesis
• Included in genesis: no
• Shipped with node image: no
• Installer: xian-dex/scripts/bootstrap_dex.py

On-Chain Contracts

The bundle deploys four contracts in a pinned order:

Contract	Role
con_pairs	pair factory, reserve bookkeeping, and LP balance logic
con_dex	router-style liquidity and swap entrypoints
con_dex_helper	convenience helper around the router for single-pair buy/sell flows
con_lp_token	XSC-0001-compatible LP token template for pairs that mint transferable LP tokens

Behavior worth knowing before integrating:

• Pair balance crediting is router-driven; unsolicited token transfers into con_pairs are not attributed to any pair.
• The standard swap fee path is 30 bps. Router-owner-approved signers can be flagged with set_zero_fee_trader(...) for zero-fee routing through the router; direct pair swaps stay on the standard fee path.
• Every pair binds an XSC-0001 LP token contract. Create pairs with createPair(tokenA, tokenB, lpToken=...) or pass lpToken=... to addLiquidity for router auto-creation.
• Fee-on-transfer tokens must be flagged with set_fee_on_transfer_token(...); plain swap routes reject flagged tokens and require the supporting-fee router path instead.
• Tokens exposing get_metadata().precision route with precision-aware amount normalization.
• con_dex_helper requires an explicit absolute deadline value.

SnakX Web Frontend

The SnakX frontend (web/, Vite + React + TypeScript) talks to the canonical contract names through @xian-tech/client for reads and the injected browser wallet provider for writes:

Route	Purpose
/swap	quote and execute swaps with live price impact, slippage, deadline, and approval handling
/pools	searchable, sortable list of every pair with reserves and mid-prices
/pools/:id	pair detail: reserves, prices, LP balance, and pool share
/liquidity	add/remove liquidity, new-pair creation, router and LP-token approvals
/portfolio	all token balances plus every LP position

cd xian-dex/web
npm install
npm run dev

Installing The DEX

Products are installed from their owning repo after a chain exists. Validate the hash-pinned bundle with the generic xian-cli helper, then run the repo-owned bootstrap against a healthy node:

uv run --project ../xian-cli xian contract bundle validate contract-bundle.json
XIAN_NODE_URL=http://127.0.0.1:26657 \
XIAN_WALLET_PRIVATE_KEY="$XIAN_PRIVATE_KEY" \
  uv run python scripts/bootstrap_dex.py --recipe local-demo

The core recipe deploys only the DEX contracts; local-demo also seeds a demo token and liquidity for local testing. For a stack-managed localnet, see Local DEX Bootstrap.

Reading DEX State From SDKs

from xian_py import Xian

with Xian("http://127.0.0.1:26657") as client:
    pair = client.contract("con_pairs").call(
        "pairFor", tokenA="currency", tokenB="demo_token",
    )
    quote = client.contract("con_dex").call(
        "getAmountsOut", amountIn=10, src="currency", path=[pair],
    )

import { XianClient } from "@xian-tech/client";

const client = new XianClient({ rpcUrl: "http://127.0.0.1:26657" });
const pair = await client.contract("con_pairs").call("pairFor", {
  tokenA: "currency",
  tokenB: "demo_token",
});

Status

candidate. Contracts are usable and covered by package-local tests, but still deserve deeper hardening before being treated as a polished production drop-in.

Related Pages

• Products overview
• xian-dex-automation
• Local DEX Bootstrap