export interface CompressionReport {
    originalBytes: number;
    compressedBytes: number;
    compressionRatio: number;
    vectorCount: number;
    dim: number;
    encodingError: {
        meanAbs: number;
        max: number;
    };
    durationMs: number;
}
export interface QuantizedEntry {
    q: Int8Array;
    scale: number;
}
export interface CompressedIndex {
    vectors: Map<string, QuantizedEntry>;
    dim: number;
    recallFn: (query: number[], topK: number) => Array<{
        id: string;
        score: number;
    }>;
}
export interface RoundtripErrorReport {
    meanAbs: number;
    max: number;
    samples: number;
}
export declare class BrainQuantize {
    /** Symmetric int8 quantization with per-vector scale. */
    quantize(vector: number[]): Int8Array;
    /** Recover an approximation of the original float vector. */
    dequantize(q: Int8Array, scale: number): number[];
    /**
     * Cosine similarity on quantized vectors WITHOUT dequantizing first.
     *
     * If `a` and `b` were derived from unit-norm float vectors, the cosine is
     * just the dot product after rescaling. We compute the integer dot then
     * apply `scaleA * scaleB` to convert back to the float dot, and clamp to
     * [-1, 1] for numeric safety. Note: the dim/127^2 factor in the spec is the
     * theoretical worst-case scale (when every element is ±127); the actual
     * normalization is captured entirely by scaleA*scaleB, so we use that and
     * do not double-divide. The clamp guards against quantization rounding
     * pushing the result slightly out of range.
     */
    cosineQuantized(a: Int8Array, scaleA: number, b: Int8Array, scaleB: number): number;
    /** Convert a v2 sharded JSON index into a single compressed .q8 binary. */
    compressIndex(srcPath: string, outPath: string): Promise<CompressionReport>;
    /** Load a .q8 file and return vectors plus a ready-to-use recall function. */
    loadCompressedIndex(filePath: string): Promise<CompressedIndex>;
    /** Self-test: report mean / max absolute reconstruction error on `vectors`. */
    quantizeRoundtripError(vectors: number[][]): RoundtripErrorReport;
    private scaleOf;
    private readShardDocs;
    private collectDocs;
    private measureBytes;
    private atomicWrite;
}
export declare function getBrainQuantize(): BrainQuantize;
export declare function resetBrainQuantizeForTests(): void;
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