import type { Agent } from "../agent.js";
export interface PayOptions {
    /** Refuse to pay if the facilitator wants more than this. Undefined = no cap. */
    maxAmountUsd?: number;
    /** Hint for facilitators accepting multiple chains. */
    preferredChain?: "solana" | "polygon" | "ethereum" | "stellar";
    /** `auto` | `aifinpay` | `coinbase-x402`. Forces a specific adapter. */
    facilitator?: string;
    /** Extra headers to attach AFTER the facilitator's auth headers. */
    extraHeaders?: Record<string, string>;
}
/** What a facilitator returns to drive the retry. */
export interface AuthPayload {
    headers?: Record<string, string>;
    /** Optional replacement body (string already serialized). */
    body?: string;
    /** Optional method override. */
    method?: string;
}
/** Immutable details of the request that received a 402 challenge. */
export interface AuthRequestContext {
    /** Canonical URL the SDK sent without credentials. */
    url: URL;
    /** Uppercase HTTP method the SDK sent without credentials. */
    method: string;
    /** Origin explicitly configured on the Agent, never inferred from a 402 body. */
    trustedOrigin: string;
    /** SHA-256 of the exact request body bytes sent before the challenge. */
    bodyDigest: string;
}
/**
 * A facilitator handles ONE x402 wire format. Implementations are
 * stateless; state (keypair, base URL) lives on the Agent.
 */
export interface Facilitator {
    readonly name: string;
    /** Build the auth payload to merge into the retry request. */
    buildAuth(response: Response, agent: Agent, options: PayOptions, context?: AuthRequestContext): Promise<AuthPayload>;
}
/** Constructor + static `detect` predicate together. */
export interface FacilitatorClass {
    new (...args: any[]): Facilitator;
    readonly name: string;
    detect(response: Response): Promise<boolean> | boolean;
}
//# sourceMappingURL=base.d.ts.map