export interface ProjectEnvironmentScope {
    /** Canonical project slug authorized by the credential. */
    projectSlug: string;
    /** Canonical project ID when the control plane supplied one. */
    projectId?: string;
    environmentId: string;
    token: string;
}
export declare function unwrapReplayedProjectEnvironmentFailure(error: unknown): {
    error: unknown;
    replayed: boolean;
};
type Fetcher = (scope: ProjectEnvironmentScope, signal: AbortSignal) => Promise<Record<string, string>>;
export interface EnvironmentVariableCacheOptions {
    /** Maximum time allowed for one cache-owned upstream fetch. */
    fetchTimeoutMs?: number;
    /** Maximum number of distinct upstream fetches across all projects. */
    maxInflight?: number;
    /** Maximum number of distinct upstream fetches for one canonical project. */
    maxInflightPerProject?: number;
    /**
     * How long a failed fetch is rethrown before the upstream is retried.
     * Collapses per-request refetch storms during a persistent upstream refusal
     * without ever serving stale or empty data. Zero disables negative caching.
     */
    failureTtlMs?: number;
    /** Mark replayed failures so an error boundary can suppress duplicate reporting. */
    markFailureReplays?: boolean;
}
export declare class EnvironmentVariableCache {
    private cache;
    private failures;
    private inflight;
    private inflightByProject;
    private fetcher;
    private ttlMs;
    private maxEntries;
    private fetchTimeoutMs;
    private maxInflight;
    private maxInflightPerProject;
    private failureTtlMs;
    private markFailureReplays;
    private globalEpoch;
    private environmentEpochs;
    constructor(fetcher: Fetcher, ttlMs?: number, maxEntries?: number, options?: EnvironmentVariableCacheOptions);
    get(scope: ProjectEnvironmentScope): Promise<Record<string, string>>;
    invalidate(environmentId?: string): void;
    private fetch;
    private captureEpoch;
    private isCurrentEpoch;
    private assertAdmission;
    private addInflight;
    private removeInflight;
    private invalidateInflight;
    /** Evict oldest recorded failures when they exceed maxEntries. */
    private evictFailuresIfNeeded;
    /** Evict oldest entries when cache exceeds maxEntries. */
    private evictIfNeeded;
}
export {};
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