VelesDB Mobile
Native bindings for iOS (Swift) and Android (Kotlin) via UniFFI.
VelesDB Mobile brings microsecond vector search to edge devices - perfect for on-device AI, semantic search, and RAG applications.
Features
- Native Performance: Direct Rust bindings, no FFI overhead
- Multi-Query Fusion: Native MQG with RRF/Weighted strategies ⭐ NEW v1.1.0
- Binary Quantization: 32x memory reduction for constrained devices
- ARM NEON SIMD: Optimized for mobile processors (Apple A-series, Snapdragon)
- Offline-First: Full functionality without network connectivity
- Thread-Safe: Safe to use from multiple threads/queues
Quick Start
Swift (iOS)
import VelesDB
// Open database
let db = try VelesDatabase.open(path: documentsPath + "/velesdb")
// Create collection (768D for MiniLM, 384D for all-MiniLM-L6-v2)
try db.createCollection(name: "documents", dimension: 384, metric: .cosine)
// Get collection
guard let collection = try db.getCollection(name: "documents") else {
fatalError("Collection not found")
}
// Insert vectors
let point = VelesPoint(
id: 1,
vector: embedding, // [Float] from your embedding model
payload: "{\"title\": \"Hello World\"}"
)
try collection.upsert(point: point)
// Search
let results = try collection.search(vector: queryEmbedding, limit: 10)
for result in results {
print("ID: \(result.id), Score: \(result.score)")
}
Kotlin (Android)
import com.velesdb.mobile.*
// Open database
val db = VelesDatabase.open("${context.filesDir}/velesdb")
// Create collection
db.createCollection("documents", 384u, DistanceMetric.COSINE)
// Get collection
val collection = db.getCollection("documents")
?: throw Exception("Collection not found")
// Insert vectors
val point = VelesPoint(
id = 1uL,
vector = embedding, // List<Float> from your embedding model
payload = """{"title": "Hello World"}"""
)
collection.upsert(point)
// Search (use Dispatchers.IO for async)
val results = withContext(Dispatchers.IO) {
collection.search(queryEmbedding, 10u)
}
results.forEach { result ->
println("ID: ${result.id}, Score: ${result.score}")
}
Build Instructions
Prerequisites
# Install Rust targets
rustup target add aarch64-apple-ios # iOS device
rustup target add aarch64-apple-ios-sim # iOS simulator (ARM)
rustup target add x86_64-apple-ios # iOS simulator (Intel)
rustup target add aarch64-linux-android # Android ARM64
rustup target add armv7-linux-androideabi # Android ARMv7
rustup target add x86_64-linux-android # Android x86_64
# For Android: Install cargo-ndk
cargo install cargo-ndk
iOS Build
# Build for device
cargo build --release --target aarch64-apple-ios -p velesdb-mobile
# Build for simulator
cargo build --release --target aarch64-apple-ios-sim -p velesdb-mobile
# Generate Swift bindings
cargo run --bin uniffi-bindgen generate \
--library target/aarch64-apple-ios/release/libvelesdb_mobile.a \
--language swift \
--out-dir bindings/swift
# Create XCFramework (requires macOS)
xcodebuild -create-xcframework \
-library target/aarch64-apple-ios/release/libvelesdb_mobile.a \
-headers bindings/swift \
-library target/aarch64-apple-ios-sim/release/libvelesdb_mobile.a \
-headers bindings/swift \
-output VelesDB.xcframework
Android Build
# Build for all Android ABIs
cargo ndk -t arm64-v8a -t armeabi-v7a -t x86_64 \
build --release -p velesdb-mobile
# Generate Kotlin bindings
cargo run --bin uniffi-bindgen generate \
--library target/aarch64-linux-android/release/libvelesdb_mobile.so \
--language kotlin \
--out-dir bindings/kotlin
# Libraries are in:
# - target/aarch64-linux-android/release/libvelesdb_mobile.so
# - target/armv7-linux-androideabi/release/libvelesdb_mobile.so
# - target/x86_64-linux-android/release/libvelesdb_mobile.so
API Reference
VelesDatabase
| Method |
Description |
open(path) |
Opens or creates a database at the specified path |
createCollection(name, dimension, metric) |
Creates a new vector collection |
createCollectionWithStorage(name, dimension, metric, storageMode) |
Creates collection with IoT storage optimization |
getCollection(name) |
Gets a collection by name (returns nil/null if not found) |
listCollections() |
Lists all collection names |
deleteCollection(name) |
Deletes a collection |
VelesCollection
| Method |
Description |
search(vector, limit) |
Finds k nearest neighbors |
searchWithFilter(vector, limit, filterJson) |
Search with metadata filter |
multiQuerySearch(vectors, limit, fusion, fusionParams) |
Multi-query fusion (MQG) ⭐ NEW v1.1.0 |
textSearch(query, limit) |
BM25 full-text search |
textSearchWithFilter(query, limit, filterJson) |
Text search with filter |
hybridSearch(vector, query, limit, vectorWeight) |
Combined vector + text search |
hybridSearchWithFilter(...) |
Hybrid search with metadata filter |
batchSearch(searches) |
Batch search with individual filters per query |
query(queryStr, paramsJson) |
Execute VelesQL query (v0.8.5+) |
upsert(point) |
Inserts or updates a single point |
upsertBatch(points) |
Batch insert/update (faster for bulk operations) |
delete(id) |
Deletes a point by ID |
count() |
Returns the number of points |
dimension() |
Returns the vector dimension |
Distance Metrics
| Metric |
Description |
Use Case |
Cosine |
Cosine similarity (1 - cosine_distance) |
Text embeddings, normalized vectors |
Euclidean |
L2 distance |
Image features, unnormalized vectors |
DotProduct |
Dot product |
Pre-normalized vectors, MaxSim |
Hamming |
Hamming distance for binary vectors |
Binary embeddings, LSH |
Jaccard |
Jaccard similarity for sets |
Sparse vectors, tags |
Storage Modes (IoT/Edge)
| Mode |
Compression |
Memory/dim |
Recall Loss |
Use Case |
Full |
1x |
4 bytes |
0% |
Best quality |
Sq8 |
4x |
1 byte |
~1% |
Recommended for mobile |
Binary |
32x |
1 bit |
~5-10% |
Extreme constraints (IoT) |
// iOS - Create collection with SQ8 compression (4x memory reduction)
try db.createCollectionWithStorage(
name: "embeddings",
dimension: 384,
metric: .cosine,
storageMode: .sq8 // 4x less memory, ~1% recall loss
)
// Android - Binary quantization for IoT devices (32x compression)
db.createCollectionWithStorage(
"embeddings", 384u, DistanceMetric.COSINE, StorageMode.BINARY
)
Performance Tips
- Use SQ8 or Binary Quantization for memory-constrained devices
- Batch inserts with
upsertBatch() for 10x faster bulk loading
- Use
search() on background thread to avoid blocking UI
- Pre-allocate embedding arrays to reduce allocations
Memory Footprint
| Vectors |
Dimension |
Storage Mode |
Memory |
| 10,000 |
384 |
Full (f32) |
~15 MB |
| 10,000 |
384 |
SQ8 |
~4 MB |
| 10,000 |
384 |
Binary |
~0.5 MB |
| 100,000 |
768 |
Full (f32) |
~300 MB |
| 100,000 |
768 |
Binary |
~10 MB |
License
VelesDB is licensed under the Elastic License 2.0 (ELv2).
This is a source available license that allows free use for most purposes,
with restrictions on providing VelesDB as a managed service (DBaaS).