Skip to content
HeliosDB HeliosDB Lite

HeliosDB-Lite Documentation

High-performance embedded database with vector search, time-travel queries, and Git-like branching

Rust License

What is HeliosDB-Lite?

HeliosDB-Lite is a lightweight, embeddable database engine written in Rust that combines the simplicity of SQLite with advanced features typically found in enterprise databases:

  • PostgreSQL-Compatible SQL - Standard SQL syntax with 95%+ PostgreSQL compatibility
  • Vector Search - Built-in HNSW indexing for similarity search and AI/ML applications
  • Database Branching - Git-like branching for development, testing, and experimentation
  • Time-Travel Queries - Query historical data at any point in time
  • Materialized Views - Automatic and incremental view refresh
  • Multi-Tenancy - Row-level security and tenant isolation

Quick Start

Installation

HeliosDB-Lite is source-available under SSPL-1.0 and is distributed to licensed customers. It is not published on crates.io, PyPI, npm, Docker Hub or Homebrew. To get access, contact sales@heliosdb.com.

With the source distribution unpacked, build the server / REPL binary:

Terminal window
cd heliosdb-lite
cargo build --release
export PATH="$PWD/target/release:$PATH"

From Python, Node.js, Go and other languages, connect to a running Lite server with any PostgreSQL driver, or with the Apache-2.0 client SDKs in HeliosDatabase/HeliosDB-SDKs (see SDKs & Integrations).

Try the REPL

Terminal window
# Start interactive shell
heliosdb-lite repl --data-dir ./mydb


# Or in-memory mode
heliosdb-lite repl --memory
CREATE TABLE users (id INT PRIMARY KEY, name TEXT);
INSERT INTO users VALUES (1, 'Alice');
SELECT * FROM users;

Run the Server

Terminal window
# The server refuses to start without a REST token-signing secret
export HELIOSDB_JWT_SECRET="$(openssl rand -hex 32)"
heliosdb-lite start --data-dir ./mydb      # PostgreSQL wire on 127.0.0.1:5432, REST on 8080


psql -h 127.0.0.1 -p 5432 -U postgres

Key Features

  • Database Branching: create isolated branches for development, testing, or experimentation without duplicating data.
  • Time-Travel Queries: query data as it existed at any point in time using AS OF TIMESTAMP syntax.
  • Vector Search: built-in HNSW vector indexing for similarity search, RAG applications, and embeddings.
  • Materialized Views: stored query results refreshed in full, concurrently or incrementally; automatic background refresh is planned.

Deployment Options

ModeDescriptionBest For
EmbeddedIn-process engine (licensed source distribution)Applications, edge devices, testing
ServerPostgreSQL-compatible serverMulti-client access, production
In-MemoryRAM-only storageTesting, caching, ephemeral data

Documentation Sections

  • Getting Started - Installation, quick start, deployment
  • User Guide - SQL reference, REPL commands, configuration
  • Features - Branching, time-travel, vectors, security
  • API Reference - REST API and the Python, TypeScript and Go SDKs
  • Releases - Changelog and release notes

Need help? Check the FAQ or contact support@heliosdb.com.