@somnia-chain/markets-sdk

The TypeScript SDK for building on Somnia Markets — read live market data and place trades on the on-chain order book from your own app.

• Realtime data, no wallet required. Order books, trades, candles, and a user's positions and open orders stream into your UI the moment they happen on-chain — no polling loops to write or manage.
• Trading with a signer. Place and cancel orders, mint and redeem outcome shares, and more, through a typed trader bound to your wallet.
• Works anywhere, with first-class React. Use plain async functions in any environment, or drop in the hooks for components that update themselves.

Install

pnpm add @somnia-chain/markets-sdk viem   # npm / yarn / bun equivalents work too

viem is a peer dependency. react is an optional peer — only needed for the @somnia-chain/markets-sdk/react entry.

Versions up to 0.19.0 were published to GitHub Packages under the private @somnia-chain scope; from 0.20.0 the package is public on npm — no registry configuration or token needed.

Create an exchange

new SomniaMarkets(config) is the single entry point — the exchange owns everything: symbols, market data, watches, and writes. No global setup, no hidden singleton; each exchange is isolated.

import { SomniaMarkets, SOMNIA_MAINNET_ADDRESSES } from "@somnia-chain/markets-sdk";
import { somniaMainnet } from "@somnia-chain/markets-sdk/chains"; // every Somnia network, incl. Shannon/Elwood/Hideki/local

const exchange = new SomniaMarkets({
  indexerUrl: "https://prd.smk.somnia.host/v1/graphql", // the production indexer
  chain: somniaMainnet,
  wsRpcUrl: "wss://api.infra.mainnet.somnia.network/ws",
  addresses: SOMNIA_MAINNET_ADDRESSES, // baked-in per-chain constants (SOMNIA_TESTNET_ADDRESSES for testnet)
  privateKey, // optional — needed for createOrder & friends
});
await exchange.loadMarkets();

const book  = await exchange.watchOrderBook("BTC-95000-31DEC26/USDC#YES"); // live, zero RTT
const order = await exchange.createOrder("BTC-95000-31DEC26/USDC#YES", "limit", "buy", 10, 0.62);

For testnet, swap all four: https://dev.smk.somnia.host/v1/graphql, somniaShannon, wss://api.infra.testnet.somnia.network/ws, and SOMNIA_TESTNET_ADDRESSES.

The raw engine tier — bigint-exact, address-keyed — is reached through the exchange (exchange.client, exchange.trader), never constructed separately. The WebSocket opens lazily on first chain I/O, so an indexer-only exchange (e.g. server-side GraphQL reads) never opens one. Nothing is shared between instances: a bot per chain, per-request servers, parallel tests — just construct another. Two exchanges never share watch state or sockets.

The guides, in reading order:

• The exchange API — the SomniaMarkets class, the SDK's primary surface: symbols (SOMI/USDC, BTC-95000-31DEC26/USDC#YES), fetch*/watch*/createOrder, human-unit structs. Exchange-bot muscle memory (ccxt included) transfers directly — start here.
• Spot markets — base/quote books: ticks and lots, native-base escrow, market orders, and stop orders.
• Binary markets — YES/NO information markets: probability prices, the four sides, mint/burn/redeem, and a maker loop.
• Perps — live on testnet: cross-margin via the MarginBank, funding, positions, and how perps slot into the marketType union.
• Price feeds — realtime BTC/ETH index prices from the on-chain EMA oracle: watchPrice/getLivePrice, one-shot history + candles, and the React hooks.
• SomniaLend — the third-party money market wrapped as client.lend: supply idle collateral, borrow working capital, reserve rates as APYs.
• Chains — every Somnia network as a viem Chain (mainnet, Shannon, Elwood, Hideki, local anvil) from @somnia-chain/markets-sdk/chains, plus getSomniaChain(id).
• Bridge — moving tokens between Somnia networks over the Hyperlane warp routes: the token/network enums, the per-network registry, and createBridgeTransfer → the unsigned transactions that do it.
• Native RPC — the somnia_* namespace wrapped as ordinary calls: the native ledger block, chain statistics, protocol parameters, reactivity subscription reads, and session transactions (the node holds the key, tracks the nonce, signs, and returns the receipt).
• Reactivity — Somnia's event-driven primitive via @somnia-chain/markets-sdk/reactivity (a pointer at the upstream @somnia-chain/reactivity package): events pushed with the state that goes with them, into TypeScript (watch) or into a Solidity handler (subscribe).
• The engine (advanced) — the raw tier behind the exchange (exchange.client / exchange.trader): bigint-exact reads, ref-counted watches, React hook wiring, raw writes.
• Architecture guide — diagrams of the whole machine: the watch seam, event routing, the local order book, the reconnect lifecycle, and the one-round-trip write path.

Two ways to read

So client.getFills fetches once; client.getLiveFills reads the live tape; useLiveFills re-renders a component as it updates. In React, provide the client once with <SomniaMarketsProvider client={client}> (from @somnia-chain/markets-sdk/react) and the hooks read it from context.

Markets come from one discriminated union — Market = SpotMarket | PerpMarket | BinaryMarket, keyed on marketType — via client.listMarkets / client.getMarket. Binary-only callers can use client.listBinaryMarkets / client.getBinaryMarket, the same query pre-narrowed to BinaryMarket. (Note: binary, not clob — a spot market is an order book too, so "CLOB" was never the right label for the binary surface.)

Money crosses the API as raw integers (bigint on writes, decimal strings from the indexer) scaled by token decimals. Convert at the edges with fromHuman (input) and toHuman / toHumanString (display); for binary prices, probabilityToPrice / priceToProbability map a YES price ↔ a 0–1 probability.

What's included

• Entry point — new SomniaMarkets(config) → the exchange (symbols, fetch*/watch*/createOrder, human-unit structs). Its engine tier — exchange.client (SomniaMarketsClient, bigint-exact reads + watches) and exchange.trader (raw writes) — is reached through it; ClientConfig
• React — SomniaMarketsProvider, useSomniaMarketsClient, and the hooks useWatchMarket, useWatchUser, useLiveStatus, useIsTailing, useLiveFills, useLiveUserFills, useLiveMarketByPool, useLiveMarketByAddress, useLiveUserOrders, useLiveBinaryOrderBook, useLiveSpotOrderBook — the pool-keyed data hooks watch automatically while mounted
• Client reads — client.listMarkets/getMarket (the Market union), listBinaryMarkets/getBinaryMarket, getCandles, getBinaryOrderBook, getOpenOrders, getPortfolio, getSyncStatus, getMarketOnchain, getSystemInfo, … (indexer reads throw on failure — an empty result always means "no rows", never "request failed")
• Order state at chain head — getOrderOnchain(pool, orderId), getOwnOpenOrdersOnchain(pool, owner), getAllOpenOrdersOnchain(pool, { isBid }) answer from the pool contract, so an order is readable the moment its block lands. Use these to read your own writes; use the indexed getOpenOrders / getOrders for history — the chain surface only knows what is open now
• Live watches (no React) — client.watchMarket(pool) / watchMarkets({ discover }) / watchUser(account) → ref-counted handles; getWatchStatus, subscribeLive, getLiveStatus, getLiveMarkets, getLiveMarketByPool/…ByAddress, getLiveFills, getLiveUserFills, getLiveUserOrders, and the locally materialized resting books getLiveBinaryOrderBook (binary, 4-sided) / getLiveSpotOrderBook — synchronous, zero round-trips, scoped to what you watch. Every market kind streams; a discovery watch picks up new markets from the creation events (the MarketCreator's rolling series AND direct BinaryMarketsModule.createMarket markets); binary status/resolution stays current from chain events.
• Trading — client.createTrader(...) → placeOrder, cancelOrder, approveBuilder (opt a routing/builder frontend in for per-order builder fees), placeSpotOrder, placeSpotStopOrder, mintSet, burnSet, redeem, faucet, resolve, voidMarket. Each write awaits its receipt and resolves to { hash, receipt } (placeOrder adds orderId + fills). With a privateKey/local account the SDK signs locally with fixed fees and a locally-tracked nonce, and sends via Somnia's realtime_sendRawTransaction — send + confirm in one round-trip, zero fee/nonce/gas estimation RPCs. In the browser, pass a walletClient (confirm rides the newHeads subscription).
• Types & helpers — Market/SpotMarket/BinaryMarket (+ isSpotMarket/ isBinaryMarket), LiveFill, LiveOrder, BinarySide, TailStatus, kindOf, fillKind, fromHuman/toHuman, DECIMALS, …
• Chains (@somnia-chain/markets-sdk/chains) — somniaMainnet (5031), somniaShannon (Shannon, 50312), somniaElwood (50313), hidekiTestnet (50383, 10 ms blocks) and somniaLocal (anvil, 31337) as viem Chains, plus somniaChains / getSomniaChain(id) / isSomniaChainId. Nothing here imports chains from viem/chains any more
• Bridge (same /chains entry) — the Hyperlane warp routes between Somnia networks as live-verified data (BridgeToken, ChainId, SOMNIA_BRIDGE, getBridgeToken, getBridgeNetwork, …) plus createBridgeTransfer(...) → the ordered, tagged unsigned transactions (approve then bridge) that move a balance. Pure: no RPC, no signer. ⚠️ dev/test bridge — not for real funds
• Native RPC (@somnia-chain/markets-sdk/native) — createNative(client) wraps the node's somnia_* namespace, exactly the twelve methods in the public JSON-RPC reference: getBlock (the native ledger block), getStatistics, listPrivilegedReceipts, getNodePublicKeys, the reactivity subscription reads, and sendSessionTransaction — plus sessionAddress(seed) / sessionPrivateKey(seed), derived locally with no round-trip. Takes any EIP-1193 client, needs nothing else from the SDK
• Reactivity (@somnia-chain/markets-sdk/reactivity) — a pointer at @somnia-chain/reactivity (optional peer dep, re-exported verbatim — no second copy of it here): createReactivity(exchange.client) → watch (a somnia_watch socket subscription that delivers each event together with eth_call results from the same block), subscribe / subscribeRaw / unsubscribe (Solidity handler subscriptions via the precompile) and scheduleSubscriptionAt{Timestamp,Block,Epoch}, plus unwrap() to turn upstream's Error-returns into throws

Every method, hook, and type is listed in the API reference.

Using a query library (TanStack Query, SWR, …)

The SDK deliberately ships no cache-library wrapper. Two rules cover the whole surface:

• Live hooks need no cache. The useLive* hooks read a push-fed store that is already a shared singleton — ref-counted watches and deduped hydration mean ten components on one pool cost one subscription. Wrapping them in a query cache would cache a value that is already live; don't.
• Async reads go in YOUR query library, with an exchange.client method as the queryFn and the SDK's exported key factory as the queryKey. Every client read is a plain promise, which is already the ideal queryFn, and the key factories (marketsKey, portfolioKey, candlesKey, syncStatusKey, marketOnchainKey, …) are plain functions from the root entry — no query library is imported, so they work with any of them. (Client reads take no per-request AbortSignal — cancellation is client-scoped via ClientConfig.signal; pass your query library's signal to any fetching your queryFn does itself.)

import { useQuery } from "@tanstack/react-query";
import { candlesKey } from "@somnia-chain/markets-sdk";

const { data: candles } = useQuery({
  queryKey: candlesKey(pool, 60, { limit: 500 }),
  queryFn: () => client.getCandles(pool, 60, { limit: 500 }),
  refetchInterval: 15_000,
});

After a write, invalidate by the same factory — queryClient.invalidateQueries({ queryKey: portfolioKey(account) }) — or everything SDK-shaped at once with the ["somnia-markets"] prefix (QUERY_KEY_SCOPE). Hand-written key strings drift; the factories are the one canonical spelling per read.

Outside a query library, useIndexerQuery(fn, deps) remains the built-in option: it re-runs on dep changes, keeps data/loading/error, and aborts a superseded request via the AbortSignal it passes to fn.

How the live feed works

You get instant updates without running your own indexer — scoped to exactly the markets you watch. Opening a watch loads a consistent snapshot of that scope (the one and only indexer touch), then keeps it current by streaming its on-chain events over a WebSocket — so trades, orders, prices, and the resting order book itself update the moment they're final on-chain. There is no polling anywhere: the WebSocket is the only realtime transport, and if it drops the watches heal themselves by reconnecting with backoff and backfilling the missed blocks straight from chain.

Debugging

The SDK is silent by default. To see what a client is doing — every trader call, the sign/broadcast pipeline, live-tail hydration and block application — pass a debug sink in the config. Events are structured data (DebugEvent: log lines plus span start/end pairs with ids, explicit parentId links, durations, and errors), so the sink owns all filtering and formatting. The toggle mechanism belongs to your app, not the SDK:

The bundled consoleDebugSink() renders the stream as an indented span tree (reconstructed from parentId, so it stays correct under concurrency):

[sdk] ▶ trader.placeOrder { params: { pool: "0x…", side: "BUY_YES" } }
[sdk]   ▶ trade.execute { functionName: "placeBinaryOrder", … }
[sdk] liveTail applying logs { received: 3, … }
[sdk]     ▶ trade.signCall
[sdk]     ◀ trade.signCall 2.1ms
[sdk]     · trade.execute { hash: "0x…" }
[sdk]   ◀ trade.execute 38.2ms
[sdk] ◀ trader.placeOrder 41.0ms

import { consoleDebugSink } from "@somnia-chain/markets-sdk";

// Browser (explorer dev) — flip on from devtools with
// localStorage.setItem("sdk-debug", "1") and reload:
const exchange = new SomniaMarkets({
  ...config,
  debug: localStorage.getItem("sdk-debug") ? consoleDebugSink() : undefined,
});

// Node bot — JSON lines behind an env var:
const exchange = new SomniaMarkets({
  ...config,
  debug: process.env.SDK_DEBUG
    ? (e) => console.log(JSON.stringify(e, (_, v) => (typeof v === "bigint" ? v.toString() : v)))
    : undefined,
});

In tests, debugCollector() captures the stream with typed filters:

import { debugCollector } from "@somnia-chain/markets-sdk";

const c = debugCollector();
const exchange = new SomniaMarkets({ ...config, debug: c.sink });
await exchange.trader.placeOrder(params);
expect(c.starts("trade.execute")).toHaveLength(1);

Span events map 1:1 onto OpenTelemetry (name ↔ span name, data ↔ attributes, error ↔ status, parentId ↔ context link), so a real tracer is just a sink that keeps a Map<id, Span> — phase: "start" calls tracer.startSpan(...) (linking parentId via OTel context) and phase: "end" calls span.end(). The OTel dependency lives entirely in your app; the SDK stays dependency-free.