import { z } from "zod";
import type { SupportedChain, UnsignedTx } from "../../types/index.js";
/**
 * Distinctive description tag used whenever an approval is emitted at
 * maxUint256. Makes it easy to eyeball the Ledger preview text and also lets
 * tests assert the user-visible surfacing.
 */
export declare const UNLIMITED_APPROVAL_WARNING = "[WARNING: UNLIMITED APPROVAL \u2014 verify on Ledger device screen]";
/**
 * Shared ERC-20 approval builder. Every prepare_* tool that needs an allowance
 * before its main call routes through buildApprovalTx() so the USDT reset
 * pattern, the optional cap logic, and the description string stay in one
 * place. Previously each module hand-rolled its own `ensureApprovalTx` with
 * subtle divergences (some exact, some unlimited, some missing the USDT
 * reset).
 */
/**
 * Resolves the caller-supplied `approvalCap` to a concrete bigint and a
 * human-readable display string.
 *
 * Semantics:
 *   undefined / "unlimited" → maxUint256 (traditional DeFi UX default)
 *   "exact"                 → amountWei (approve only what's needed)
 *   decimal string ("500")  → parseUnits(cap, decimals), must be ≥ amountWei
 *
 * Callers decide the default for their tool by the value they pass: omit the
 * arg to get "unlimited", or hardcode "exact" (Aave / swap already do this).
 */
export declare function resolveApprovalCap(cap: string | undefined, amountWei: bigint, decimals: number): {
    approvalAmount: bigint;
    display: string;
};
export interface BuildApprovalArgs {
    chain: SupportedChain;
    wallet: `0x${string}`;
    asset: `0x${string}`;
    spender: `0x${string}`;
    /** Amount the follow-up action will actually pull (required on-chain). */
    amountWei: bigint;
    /** Amount to approve; resolved via resolveApprovalCap. */
    approvalAmount: bigint;
    /** Display-only label for the cap (unlimited / exact amount / N capped). */
    approvalDisplay: string;
    symbol: string;
    /** Spender label for descriptions, e.g. "Compound V3 cUSDCv3". */
    spenderLabel: string;
}
/**
 * Build an approve tx (or a reset→approve chain for USDT-style tokens).
 * Returns null when no approval tx is needed.
 *
 * Three outcomes, in order:
 *   1. Current allowance already satisfies the action AND the cap — return
 *      null. "Satisfies the cap" means: the user asked for "unlimited" (no
 *      cap), OR the existing allowance is ≤ approvalAmount. In other words,
 *      we only leave the allowance alone when doing so respects the caller's
 *      intent.
 *   2. Current allowance satisfies the action BUT exceeds an explicit cap —
 *      emit reset(0) → approve(cap). The user asked for a ceiling and we
 *      enforce it even if it means an extra tx. This is the fix for the
 *      silent-no-op footgun where a prior unlimited approval would defeat a
 *      new `approvalCap: "500"` request.
 *   3. Current allowance is below what the action needs — emit approve(cap)
 *      (or reset→approve for USDT-style tokens when allowance > 0).
 */
export declare function buildApprovalTx(a: BuildApprovalArgs): Promise<UnsignedTx | null>;
/**
 * Zod schema fragment for an optional `approvalCap` tool parameter. Share
 * across every prepare_* tool that emits an approval.
 */
export declare const approvalCapSchema: z.ZodOptional<z.ZodString>;