/**
 * Receipts, and the reciprocal netting built on them.
 *
 * **The problem receipts solve.** Until now the lender's word was the only
 * record of what a borrowed request cost. The lender settles from usage the
 * borrower never sees a ledger of, and a complete-mode borrower self-reports
 * spend the lender cannot see at all. Each side simply believed the other.
 *
 * A receipt is the lender's signed statement that one request was settled, for
 * how much, and against what usage. It travels with the usage block, so the
 * borrower does not have to accept the coin figure — it recomputes the charge
 * from the response it actually received and compares. `sequence` is contiguous
 * per grant, so a receipt withheld to hide a charge leaves a hole.
 *
 * What it cannot do: an HMAC proves authorship only to the holder of the key, so
 * a receipt settles a dispute *between the two parties to it* and is worth
 * nothing to a third. That is the deliberate trade — see `shareSigning.ts`.
 *
 * **Netting.** Two nodes that lend to each other otherwise accumulate two
 * one-way debts that never meet. Netting forgives the overlap: if a borrower has
 * consumed 300 coins of mine and I have consumed 500 of theirs, 300 cancels on
 * both sides. It is expressed in *cumulative* totals rather than deltas, so a
 * replayed or duplicated round nets zero rather than paying twice.
 *
 * @module proxy/shareReceipts
 */
import type { ProxyShareNettingResult, ProxyShareReceipt, ProxyShareStatement, ProxyShareUsage } from "../types/index.js";
/**
 * Receipts kept per grant.
 *
 * Enough that a borrower checking in daily never misses one, bounded so a busy
 * grant cannot grow the file without limit. A borrower that falls further behind
 * than this sees a gap, which is the honest answer — the alternative is silently
 * dropping the evidence and reporting a clean run.
 */
export declare const RECEIPT_HISTORY_LIMIT = 500;
export declare function initShareReceipts(filePath: string): void;
/**
 * Record and sign a settlement.
 *
 * Never throws: a receipt that could not be written must not turn a response the
 * borrower already has into an error. A grant with no receipt secret — one
 * issued before receipts existed — is skipped rather than signed with nothing.
 */
export declare function issueShareReceipt(args: {
    grantId: string;
    coins: number;
    usage: ProxyShareUsage;
    model?: string;
    balanceAfter: number | null;
    settledAt?: number;
}): Promise<ProxyShareReceipt | undefined>;
/** Receipts a borrower has not collected yet. */
export declare function listShareReceipts(grantId: string, since?: number): Promise<ProxyShareReceipt[]>;
/**
 * Check a collected run of receipts against the secret and against itself.
 *
 * Three independent questions, because they have different answers:
 * a signature that does not verify means the receipt did not come from this
 * lender; a coin figure that disagrees with its own usage block means the
 * lender's arithmetic (or its price table) differs from ours; a missing
 * sequence means a charge was never shown to us at all.
 */
export declare function auditShareReceipts(grantId: string, collected: readonly ProxyShareReceipt[], secret: string | undefined): ProxyShareStatement;
/** Cumulative coins a grant has consumed, as its receipts record it. */
export declare function totalReceiptedCoins(grantId: string): Promise<number>;
/** Cumulative coins already forgiven on a grant by netting. */
export declare function nettedCoinsFor(grantId: string): Promise<number>;
/**
 * Settle one round of reciprocal netting, from the lender's side.
 *
 * Netting forgives the same amount on both sides, so the cumulative total
 * forgiven is one number the two nodes hold a copy of each. The round is
 * therefore the overlap that has not been forgiven yet:
 *
 * ```
 * forgivable = min(coins they consumed of mine, coins I consumed of theirs)
 * alreadyForgiven = max(my record, their record)
 * round = max(0, forgivable - alreadyForgiven)
 * ```
 *
 * **Why the totals and not a delta.** A delta is a number the caller chooses,
 * and a replayed round would pay it out again. Deriving the round from
 * cumulative positions makes a replay free by construction: the second call
 * subtracts the first one's forgiveness and lands on zero.
 *
 * **Why `max` over the two records.** They should agree. When they do not — a
 * round applied on one side and lost on the other — taking the larger forgives
 * less, which is the direction that cannot hand out coins twice.
 */
export declare function applyReciprocalNetting(args: {
    grantId: string;
    /** Cumulative coins this node has consumed under the *peer's* grant to it. */
    consumedFromPeer: number;
    /** Cumulative coins the peer says it has already forgiven on its side. */
    peerAlreadyNetted: number;
}): Promise<ProxyShareNettingResult>;
/** Drop a grant's receipts and netting position. Used when the grant goes. */
export declare function clearShareReceipts(grantId: string): Promise<void>;