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What exists. What’s proposed.

Request prices and quantities are human decimal strings. Convert once at a verified boundary; never assume all quantities use 18 decimals.

01 · Available for read-only integration

Discover the valid terms.

Discovery defines the available products and expiry-specific strikes. A strike accepted for one expiry is not automatically accepted for another. Each maker supplies its own configuration version.

const base = 'https://hindsight-lookback-collateral-trial.devops-118.workers.dev';
const response = await fetch(base + '/discover/lookback', {
  credentials: 'omit', referrerPolicy: 'no-referrer',
  signal: AbortSignal.timeout(12_000)
});
if (!response.ok) throw new Error(`Discovery: ${response.status}`);
const discovery = await response.json();
// Select an actual market, expiry and activation from discovery.
// Use its quantity grid, price bounds and configVersion.
const estimate = await fetch(base + '/indicative', {
  method: 'POST', credentials: 'omit', referrerPolicy: 'no-referrer',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify(selectedTerms),
  signal: AbortSignal.timeout(12_000)
});
if (!estimate.ok) throw new Error(`Quote: ${estimate.status}`);
const quote = await estimate.json(); // Indicative only, no signature.

02 · Proposed integration contract

A directory, not an execution gate.

Pin a registry address, bytecode and chain in your deployment configuration. Read its maker list at one block. The registry identifies services to query; OptionBook independently checks signed orders.

Draft status enum: 0 Inactive, 1 Active, 2 Exiting, 3 Exited. Maker IDs and indexed positions remain stable; exited records stay readable. Read makerCount and makerIdAt in pages at a shared block number. isEligible is the authoritative eligibility check.

Fan out, then compare like for like.

1. Read registry count and paginated IDs at the same block. Show enumeration coverage and any query limit; never silently imply every maker was queried.
2. Capture chain, maker revision and requested terms before concurrent work. Request each eligible HTTPS endpoint with a timeout, a bounded body reader, no credentials and no referrer. Ignore stale responses after a context change.
3. Validate each discovery against your own chain, Book, schema, token, feed and implementation allowlist. Discovery never enlarges the allowlist.
4. Ask compatible makers for the same quantity, expiry, activation, cap/floor and delivery/receive tokens. Compare total premium in the same premium token. A different collateral/token combination is a separate comparison group.
5. Show the lowest valid indicative premium returned by the deadline, how many makers responded, and any failures. Do not claim all-market best price or reserved liquidity.
6. Before an eventual fill, refresh the registry state and revision. Revalidate the signed order and simulate. A changed price or context requires a fresh user review.

// registryAbi is DRAFT-MakerRegistry-v0.json. No address is deployed.
const blockNumber = await client.getBlockNumber();
const read = (functionName, args = []) => client.readContract({
  address: configuredRegistry, abi: registryAbi,
  functionName, args, blockNumber
});
const count = await read('makerCount');
// Page makerIdAt(index) at this SAME block, then getMaker(id).
// Check isEligible(id), chain and revision before sending a request.
// Use a bounded queue, not unbounded Promise.all over the directory.
const results = await boundedMap(eligibleMakers, concurrency, async maker => {
  const discovery = await readBoundedJSON(maker.quoteBaseUrl, '/discover/lookback');
  const request = validateAndBuildExactTerms(discovery, reviewedTerms, allowlist);
  const quote = await postBoundedJSON(maker.quoteBaseUrl, '/indicative', request);
  return validateQuote(quote, request, maker, allowlist);
});
// Above callbacks are application adapters, not an exported SDK.
// Discard results if chain, request ID or registry revision has changed.
// Rank only equal terms + same premium token, using integer total amounts.
// Display enumeration, response and timeout coverage alongside the result.

Launch clients may use a bounded, disclosed maker count in registration order. Concurrency limits must not silently drop makers; queued work and deadline coverage must be visible.

Proposed · signed-offer execution for vaults

Replace the auction process.

Maker discovery and competition can happen through registered quote services. A vault still needs an onchain intent and execution policy; the registry is not a settlement contract.

1. Publish a bounded intent. Bind the vault, chain, request nonce, approved Book/product, quantity, tokens, strikes, expiry and maximum premium or minimum proceeds. Reserve the required budget in the vault’s accounting.
2. Collect matching offers. Workers return signed Book orders for the same terms. Anyone may submit a candidate or batch. A submission does not prove it is the best offer outside that batch.
3. Validate and fill atomically. Check the current intent nonce, remaining size, registry eligibility, full signed terms and Book signer policy before execution. Account for the actual receipt, consume the intent and track the created option exactly once.
4. Preserve vault accounting. Pending deposits, withdrawals, share minting, cancellations and option callbacks require an explicit integration. Keep existing Factory dependencies until equivalent responsibilities have been implemented and reviewed.

Current Book authorization supports the maker’s own signature and the supported MarketMakerBeacon operator policy. A registry record must not invent an incompatible signer rule. No generic contract-wallet signing support is implied.

03 · Future purchase and exercise flow

From a quote to a right.

The current site stops at an indicative estimate. The reference execution flow is described here for integrators; these pages do not run it.

1. Prepare. Call POST /request only after the buyer proceeds. Display the returned authoritative price and batch timing; it may differ from the earlier estimate.
2. Wait for the batch. Read GET /batches/{batchAt} inside its active window. Find the exact returned request ID. Pending or expired responses are not offers.
3. Verify. Check the EIP-712 domain (OptionBook, version 1.0, exact chain and Book), schema hash, maker account, every strike, both expiries, tokens, implementation and signed extra data. Validate current registry revision and status.
4. Simulate and fill. Validate the quantity/collateral round trip and exercise minimum. Refresh balances, allowance, nonce/cancellation and capacity. Approve the reviewed premium and call fillOrder(order, signature, referrer) only after user confirmation.
5. Exercise. Find an eligible historical oracle round and its neighbours, preview delivery, then call exercise(roundId, quantity, maxDeliveryIn) as the buyer. Exercise before expiry; unused rights are not automatically exercised.

Curated ABI subsets from source revision 87dc632. No deployment address is implied. Compare against the exact deployed bytecode before use.

04 · RH-specific accounting

Keep the share unit consistent.

RH oracle observations price a raw Stock Token. Divide by the historical multiplier to recover the ordinary-share price.

Query candidates(token, round.updatedAt) for each observation and its neighbours. Before the first record, there is no history. Between ranges or within a shared second, preserve every possible value and show the resulting price range. The live multiplier is not a replacement for historical data.

The deployed read-only registry is separate from approval or deployment of RH option trading. RH exercise and split handling still require their own integration review.