Class Searcher

Namespace: Kjarni
Assembly: Kjarni.dll

Document searcher for RAG applications.

public class Searcher : IDisposable

Inheritance

object ← Searcher

Implements

IDisposable

Examples

using var searcher = new Searcher(model: "minilm-l6-v2");
var results = searcher.Search("my_index", "What is machine learning?");
foreach (var r in results)
{
    Console.WriteLine($"{r.Score:F4}: {r.Text[..50]}...");
}

Constructors

Searcher(string, string, string?, string?, SearchMode, int, bool)

Create a new Searcher.

public Searcher(string model = "minilm-l6-v2", string device = "cpu", string? cacheDir = null, string? rerankerModel = null, SearchMode defaultMode = SearchMode.Hybrid, int defaultTopK = 10, bool quiet = false)

Parameters

model string

Embedding model name (must match the model used to create the index)

device string

Compute device - "cpu" or "gpu"

cacheDir string?

Directory to cache downloaded models

rerankerModel string?

Optional cross-encoder model for reranking

defaultMode SearchMode

Default search mode

defaultTopK int

Default number of results

quiet bool

Suppress progress output

Properties

DefaultMode

Get the default search mode.

public SearchMode DefaultMode { get; }

Property Value

SearchMode

DefaultTopK

Get the default number of results.

public int DefaultTopK { get; }

Property Value

int

HasReranker

Check if a reranker is configured.

public bool HasReranker { get; }

Property Value

bool

ModelName

Get the embedding model name used by this searcher.

public string ModelName { get; }

Property Value

string

RerankerModel

Get the reranker model name, or null if no reranker is configured.

public string? RerankerModel { get; }

Property Value

string?

Methods

Dispose()

Releases the native model. The object cannot be used afterwards.

public void Dispose()

~Searcher()

Releases the native model if was not called.

protected ~Searcher()

Search(string, string, SearchMode?, int?, bool?, float?, string?, string?, string?)

Search an index.

public List<SearchResult> Search(string indexPath, string query, SearchMode? mode = null, int? topK = null, bool? rerank = null, float? threshold = null, string? sourcePattern = null, string? filterKey = null, string? filterValue = null)

Parameters

indexPath string

Path to the index directory

query string

Search query string

mode SearchMode?

Search mode (null = use default)

topK int?

Number of results (null = use default)

rerank bool?

Use reranker (null = auto)

threshold float?

Minimum score threshold

sourcePattern string?

Filter by source file pattern (glob)

filterKey string?

Metadata key to filter on

filterValue string?

Required value for filterKey

Returns

List<SearchResult>

List of SearchResult objects

SearchKeywords(string, string, int)

Static keyword search (BM25) - no embedding model needed.

public static List<SearchResult> SearchKeywords(string indexPath, string query, int topK = 10)

Parameters

indexPath string

Path to the index directory

query string

Search query string

topK int

Maximum number of results

Returns

List<SearchResult>

List of SearchResult objects