/**
 * @name PrePaymentValidation
 * @description Rejects malformed wallet-bearing tool calls BEFORE the x402 paywall,
 * so clients never pay for a call that would fail on input validation.
 */
import type { ParsedMcpRequest } from './json-rpc.js';
export interface PrePaymentValidationFailure {
    code: number;
    message: string;
    data: {
        reason: string;
        paymentNotCharged: true;
        blockedTools: string[];
        invalidParams: Record<string, string>;
        recommendedFix: string;
    };
}
/**
 * Validates wallet-bearing arguments of every tool call in the request BEFORE the
 * x402 payment challenge. Only rejects when a value is demonstrably invalid;
 * absent params are the handler's concern (they stay payable so the tool can
 * return its own actionable "parameter required" guidance).
 *
 * @param parsedRequest - Parsed MCP request with all tool calls.
 * @returns A failure with paymentNotCharged when any wallet param is malformed.
 */
export declare function evaluatePrePaymentValidation(parsedRequest: ParsedMcpRequest): PrePaymentValidationFailure | undefined;
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