InMemoryVectorStore class

A VectorStore that keeps everything in memory.

Embeddings are stored as Float32List, which halves memory compared to doubles at a precision cost that is irrelevant for similarity search. Each document's vector norm is computed once at upsert time, so a search costs one dot product per candidate document.

Search is exact: every candidate is scored. There is no approximate index, which keeps results deterministic and works well up to roughly 100k chunks. See the package README for the measured trade-off.

The store can be serialized with toBytes and restored with InMemoryVectorStore.fromBytes. On the Dart VM and Flutter (not web), package:rag_kit/io.dart adds file-based save and load on top of these.

Inheritance

• Object
• VectorStore
• InMemoryVectorStore

Available extensions

• InMemoryVectorStoreFiles

Constructors

InMemoryVectorStore()

Creates an empty store.

InMemoryVectorStore.fromBytes(Uint8List bytes)

Restores a store from bytes produced by toBytes.

factory

Properties

dimension → int?

The embedding dimension of the stored documents, or null while the store is empty.

no setter

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

clear() → Future<void>

Removes all documents.

override

count() → Future<int>

The number of stored documents.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

removeWhere(bool test(Document document)) → Future<int>

Removes every document for which test returns true.

override

save(String path) → Future<void>

Available on InMemoryVectorStore, provided by the InMemoryVectorStoreFiles extension

Writes the store to the file at path, overwriting it if it exists.

search(List<double> query, {int topK = 5, double? minScore, bool where(Document document)?}) → Future<List<ScoredChunk>>

Returns up to topK documents most similar to query, best first.

override

toBytes() → Uint8List

Serializes the store to the rag_kit binary format.

toString() → String

A string representation of this object.

inherited

upsert(List<Document> documents) → Future<void>

Inserts documents, replacing any existing document with the same id.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited