/**
 * Plain-language copy for OAuth callback outcomes. Kept out of `mcp-oauth.ts`
 * so the direct session route loads it only when a callback actually failed.
 */
/**
 * Plain-language copy for the callback reasons every integration flow shares:
 * the user cancelling at the provider, and a stale or reused callback link.
 * Returns null for anything flow-specific so callers keep their own wording.
 */
export declare function oauthCallbackReasonMessage(reason: string | null): string | null;
/**
 * A failed OAuth callback with no flow-specific copy. A reason we have no
 * words for stays visible (as support needs it) after the generic line.
 */
export declare function oauthCallbackFailureMessage(reason: string | null): string;
export declare function mcpOAuthCallbackFailureMessage(stage: string | null, reason: string | null): string;