/**
 * Coinbase Onramp link client.
 *
 * Exchanges the user's Base wallet address for a one-time Coinbase Onramp
 * URL via the BlockRun gateway. The gateway holds the CDP API key, signs the
 * JWT, and mints a single-use `sessionToken` (Coinbase requires Secure Init
 * since 2025-07-31 — plain appId URLs are deprecated). The returned URL is
 * one-time and expires in ~5 minutes, so it must be minted at click time and
 * never cached.
 *
 * Base / USDC only. Mirrors the gateway-call pattern in src/phone/client.ts
 * and reuses the shared x402 POST helper.
 */
export interface OnrampLinkResult {
    /** One-time https://pay.coinbase.com/... URL prefilled for this wallet. */
    url: string;
}
/**
 * Mint a one-time Coinbase Onramp link that funds `address` (Base USDC).
 * Throws if the gateway is unreachable, not configured, or returns no URL.
 */
export declare function getOnrampUrl(address: string): Promise<OnrampLinkResult>;