@arkade-os/solver-discovery

A tiny, portable ESM client for the consumer (maker) side of the Arkade Market Discovery Protocol: discover the price feeds solvers advertise, rank markets, convert amounts, and compute the wantAmount for an offer.

• Runs everywhere — browser, Node, and Expo / React Native. The root entrypoint has zero runtime dependencies; only global fetch is used (and it's injectable).
• No eval / new Function — validation is hand-rolled, so it works under a strict CSP and on Hermes (React Native), where JSON-Schema engines like Ajv fail.
• Exact math — prices are BigInt rationals and amounts are BigInt, so no float error ever touches an amount.

Install

npm install @arkade-os/solver-discovery

Quick start

import { discover, listMarkets, bestMarket, quoteOffer } from "@arkade-os/solver-discovery";

// 1. Fetch + merge the registries you follow (plus any pinned local cards).
const { markets, warnings } = await discover({
  registries: ["https://arkade-os.github.io/solver-registry/bitcoin.json"],
});
if (warnings.length) console.warn(warnings);

// 2. List pairs for UI selection, then pick the best market for one pair.
//    `solvable` counts how many markets can pay out each side — don't offer a
//    direction whose receive side is at 0.
console.log(listMarkets(markets).map((p) => `${p.pair} base:${p.solvable.base} quote:${p.solvable.quote}`));
const market = bestMarket(markets, {
  baseId: "btc",
  quoteId: "47004bf4a5fbdb2221f708030528de68ea28f5980044e546b7bb5a352457d1f30000",
  wantSide: "quote", // we give base and receive quote; skips markets that can't pay out quote
});
if (!market) throw new Error("no market solves this side of the pair");

// 3. Quote an offer — fetches the advertised feed and returns a ready plan.
const plan = await quoteOffer(market, { give: "base", giveAmount: "0.01" }); // 0.01 BTC
console.log(`${plan.deposit.display} ${plan.deposit.asset.ticker}`
  + ` -> ${plan.receive.display} ${plan.receive.asset.ticker}`);
// plan.receive.atomic is the wantAmount to request; then createOffer(...) as usual.
if (!plan.limits.withinLimits) console.warn("amount is outside the market's size limits");

Corridor markets

A market side may settle on another rail: base_corridor / quote_corridor name it (arkade — the default — lightning, or onchain), and market identity is the corridor-qualified leg pair, so a Lightning BTC market and an onchain BTC market never collapse into one group. Selection takes corridors the same way it takes ids:

Upgrading from 0.1.x: corridor entries have no feed fields, and 0.1.x quoteOffer throws on them (price_feed was assumed present; its type is now string | undefined). Upgrade before following any registry that lists corridor markets — a registry should not merge its first corridor card until its clients have.

const lnMarket = bestMarket(markets, {
  baseId: "btc",
  quoteId: "btc",
  quoteCorridor: "lightning", // omit corridors and you get spot markets only
  wantSide: "quote",
});

A same-asset corridor market carries no feed — its price is identically 1 and fee_bps plus fee_flat are the whole price. quoteOffer / planOffer handle that transparently (nothing is fetched), but the plan is a pre-quote estimate: the binding amounts come from the solver's RFQ quote, requested via the market's discovery_pubkey over its transports (both present on every corridor entry). The RFQ exchange itself is out of this package's scope.

Amount conversion (Arkade Assets)

Each asset carries a decimals field (8 for BTC and most Arkade assets). Conversion between human and atomic units is exact:

import { toAtomic, fromAtomic } from "@arkade-os/solver-discovery";

toAtomic("1.5", 8);          // => 150000000n
fromAtomic(150000000n, 8);   // => "1.5"
toAtomic("1.123456789", 8);  // throws: more precision than 8 decimals allow

Pricing math always stays in atomic units; quoteOffer() does the human⇄atomic conversion for you using each side's decimals.

Price feed responses

Every market declares both the feed URL and how to read its response:

{
  "price_feed": "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin&vs_currencies=usd",
  "price_feed_schema": { "type": "json", "price_path": "/bitcoin/usd" }
}

price_path is an RFC 6901 JSON Pointer to a JSON number or numeric string. Common examples: Binance ticker price uses /price; a bare JSON number uses the empty pointer "". The client does not scan unknown response shapes.

Pin a local card

Users can pin a solver card directly (a raw card, validated against the card schema), participating in the merge like any registry entry:

const { markets } = await discover({
  registries: ["https://arkade-os.github.io/solver-registry/bitcoin.json"],
  localCards: [{ card: pastedCardJson }],
});

Expo / React Native

Works out of the box — Hermes ships fetch, AbortController, and BigInt. If you target an older runtime without global fetch, inject one:

import { discover } from "@arkade-os/solver-discovery";
await discover({ registries, fetchImpl: myFetch });

React

The optional React entrypoint keeps a two-input quote form synchronized. It fetches the market feed and recalculates the other field whenever the user edits the given or wanted amount:

import { useOfferQuote } from "@arkade-os/solver-discovery/react";

function QuoteForm({ market }) {
  const quote = useOfferQuote(market, { give: "base" });

  if (quote.solvable === false) return <p>This market cannot pay out the side you want.</p>;
  return (
    <>
      <input value={quote.giveAmount} onChange={(e) => quote.setGiveAmount(e.target.value)} />
      <input value={quote.wantAmount} onChange={(e) => quote.setWantAmount(e.target.value)} />
      <button disabled={!quote.plan?.limits.withinLimits}>Create offer</button>
    </>
  );
}

useOfferQuote(market, opts) returns the active input, both display amounts, the latest OfferPlan, loading/error state, and the give/want setters. With give: "base" the give field is the base amount and the want field the quote amount; swap them for give: "quote". quote.solvable says whether the market declares limits for — can pay out — the side received under give (null while no market is selected), and quote.plan?.receive.atomic is the wantAmount to request.

The package does not install React for you: importing @arkade-os/solver-discovery/react requires React in the app, while the root package entrypoint does not import React.

Core API

| Export | Purpose | |---|---| | discover(opts) | Fetch + merge + dedupe + rank markets across registries and local cards. Defaults to network: "bitcoin". Registry failures are isolated. | | fetchIndex(url, opts) | Fetch + validate a single per-network index (never throws). Defaults to network: "bitcoin". | | listMarkets(markets) | List available id pairs, how many solver candidates each pair has, and how many can pay out each side (solvable.base / solvable.quote). | | selectMarkets(markets, {baseId, quoteId, wantSide?, wantAmount?}) / bestMarket(..., {cursor?}) | Filter to one id pair — and optionally to markets that can pay out wantSide, sized by wantAmount on that side — keeping the ranking. cursor: 1 selects the second-ranked market. | | sideLimits(market, side) | The side's { min, max } bounds as exact bigints, or null when the solver cannot pay that side out — disabled (max = "0") or carrying malformed/validation-rejected bounds. The single per-side solvability + size-bound primitive. | | quoteOffer(market, {give, giveAmount \| wantAmount, safetyBps?}) | Fetch the feed and build a full OfferPlan (human in/out). | | planOffer({market, give, giveAmount \| wantAmount, feedValue, safetyBps?}) | Same, from an already-fetched feed value (pure/sync). | | fetchFeedValue(url, schema, opts?) | Fetch a raw feed and extract the numeric price using the market's price_feed_schema. | | deriveAtomicPrice / computeWantAmount | Pure pricing primitives (exact rationals / BigInt). | | toAtomic / fromAtomic / displayPriceString | Decimals-aware conversion. | | validateCard / validateIndex | Dependency-free, eval-free schema validation. |

give: "base" deposits the base asset and receives the quote; give: "quote" is the reverse (priced with 1/P). Pass exactly one of giveAmount or wantAmount: giveAmount fixes the deposit and computes the requested receive amount, while wantAmount fixes the requested receive amount and computes the minimum deposit. Either takes a display string/number, or a bigint to stay in atomic units. safetyBps defaults to 50 — the cushion that absorbs feed movement between funding and fill.

Markets carry size limits for both sides (min|max_base_amount, min|max_quote_amount) as decimal strings of atomic units — exact past 2^53, where JSON numbers silently round — and max = "0" disables a side: the solver cannot pay it out, so a market with zeroed base bounds only serves give: "base". Plans check the received side: plan.limits.min === null means the market cannot pay that side at all, and plan.limits.withinLimits says whether the received amount sits inside [min, max].

Roadmap

Chained (multi-hop) offers — not yet supported: bestMarket/quoteOffer match direct (baseId, quoteId) pairs only. Planned: treat markets as directed edges over canonical asset ids and route through intermediates (BTC → USDT → USDC) via findRoutes / planRoute / quoteRoute, ranking routes by the compounded net multiplier ∏(1 − (fee_bps + safety_bps)/10000) and checking size limits per hop at plan time. Note the protocol caveat: each hop executes as a separate Arkade offer, so a chained route is not atomic — plans are indicative and routing will be opt-in, never a silent fallback inside quoteOffer(). Full spec and API design: #1.

Develop

pnpm install
pnpm test        # node --test, dependency-free, runs the .ts directly
pnpm typecheck
pnpm build       # emits dist/*.js + *.d.ts

Release

From the repo root, publish a patch, minor, or major release:

npm run release:client -- patch

The last argument must be patch, minor, or major. The script must be run from master with a clean git tree, runs the package tests/typecheck/build, bumps packages/discovery-client/package.json with npm version <level> --no-git-tag-version, publishes to npm, then creates a release commit and a solver-discovery-vX.Y.Z tag, and pushes both master and the tag to origin.

You can also run the same workflow from this package directory:

npm run release -- minor

Before running it, make sure you are logged in to npm with publish rights for the @arkade-os scope.