/**
 * Model entitlement facts shared by Codex credential selection and provider
 * error presentation.
 *
 * GPT-5.6 Sol is a Pro-tier ChatGPT Codex model. The usage endpoint is the
 * authority for the account tier; this module only names the model policy and
 * keeps the provider's deterministic rejection wording in one place.
 */
export type OpenAICodexProEntitlement = "entitled" | "denied" | "unknown";
/**
 * Classify a ChatGPT `plan_type` for strict Pro-tier Codex models.
 *
 * The usage endpoint remains authoritative: only exact, documented tier names
 * are classified. Known Free/Plus tiers can be rejected locally, while missing
 * or unfamiliar values stay unknown and reach the provider instead of being
 * guessed from a substring.
 */
export declare function classifyOpenAICodexProEntitlement(planType: string | undefined): OpenAICodexProEntitlement;
export declare function requiresOpenAICodexProModel(provider: string, modelId: string | undefined): boolean;
export declare function requiresStrictOpenAICodexProModel(provider: string, modelId: string | undefined): boolean;
export declare function isOpenAICodexChatGPTEntitlementError(message: string | undefined, code?: string): boolean;
export declare function formatOpenAICodexChatGPTEntitlementError(modelId: string | undefined): string;