export type SpanStatusCode = 'UNSET' | 'OK' | 'ERROR';
export interface SpanEvent {
    name: string;
    time_ns: number;
    attributes?: Record<string, unknown>;
}
export interface TraceLine {
    trace_id: string;
    span_id: string;
    parent_span_id?: string;
    name: string;
    tracer_name: string;
    start_ns: number;
    end_ns: number;
    attributes: Record<string, unknown>;
    events: SpanEvent[];
    status: {
        code: SpanStatusCode;
        message?: string;
    };
}
export interface SpanOptions {
    attributes?: Record<string, unknown>;
    parent?: Span;
}
export declare class Span {
    readonly traceId: string;
    readonly spanId: string;
    readonly parentSpanId?: string;
    readonly name: string;
    readonly tracerName: string;
    readonly startNs: number;
    private endNs;
    private ended;
    private attrs;
    private events;
    private status;
    private tracer;
    constructor(tracer: Tracer, name: string, opts?: SpanOptions);
    setAttribute(key: string, value: unknown): this;
    addEvent(name: string, attributes?: Record<string, unknown>): this;
    recordException(err: unknown): this;
    setStatus(code: SpanStatusCode, message?: string): this;
    end(): void;
    private toLine;
}
export declare class Tracer {
    readonly name: string;
    private sampleRate;
    private lastRotation;
    constructor(name: string);
    startSpan(name: string, opts?: SpanOptions): Span;
    /** Auto begin/end around an async function. */
    withSpan<T>(name: string, fn: (span: Span) => Promise<T> | T, opts?: SpanOptions): Promise<T>;
    /** Set sample rate 0-1. 1 = emit all spans, 0 = drop all. */
    sample(rate: number): void;
    /** Internal: write a line. Sampling + rotation handled here. */
    emitSpan(line: TraceLine): void;
    private cleanupOldFiles;
}
export declare function trace(name: string): Tracer;
export declare const OtelLite: {
    trace: typeof trace;
    /** Read the tail of today's trace file. Returns parsed TraceLines, newest last. */
    tail(lines?: number): Promise<TraceLine[]>;
    /** Path of today's trace file (whether or not it exists yet). */
    todayFilePath(): string;
    /** Manually trigger retention cleanup. */
    cleanup(): void;
};
//# sourceMappingURL=otel-lite.d.ts.map