/**
 * Structured JSON logger
 *
 * Silent during tests unless DEBUG=true.
 * `debug` is opt-in everywhere, test or not: it only emits when DEBUG=true,
 * the same flag that unsilences tests, so a host enables high-volume
 * diagnostic logging (e.g. per-request content) with one env var rather than
 * a second one to learn.
 * Automatically redacts phone numbers (recursively, by key name, including
 * inside an array of raw phone strings) and previews every other string
 * field to a fixed length once it exceeds that length - a value at or under
 * the preview length logs in full, verbatim (see SECURITY.md). Set
 * TALKER_LOG_VERBOSE=true to log full, untruncated content instead of the
 * preview (phone redaction, and any field named in TALKER_LOG_REDACT_KEYS,
 * still apply).
 */
type LogLevel = "debug" | "info" | "warn" | "error";
/**
 * Whether a log at `level` actually emits, given the silence/debug policy.
 * Pure and exported so the "debug is suppressed outside DEBUG=true" case can
 * be tested directly: `isTestEnv()`'s argv half is fixed at module load (see
 * above), so under `bun test` it is always true, and `isSilent()` already
 * swallows every level whenever `DEBUG` isn't `"true"` - there is no way to
 * observe this function's non-test branch by spying on `console.log` from
 * within the suite.
 */
export declare function isLevelEnabled(level: LogLevel, opts: {
    silent: boolean;
    debugEnabled: boolean;
}): boolean;
/**
 * Redact a phone number, keeping only the last 4 digits.
 * E.g. "+15551234567" -> "***4567"
 */
export declare function redactPhone(phone: string): string;
export declare const logger: {
    debug: (message: string, data?: Record<string, unknown>) => void;
    info: (message: string, data?: Record<string, unknown>) => void;
    warn: (message: string, data?: Record<string, unknown>) => void;
    error: (message: string, data?: Record<string, unknown>) => void;
};
export {};