HeliosDB Nano

An embedded database with native PostgreSQL and MySQL wire-protocol compatibility, plus one-shot SQLite file import. Single 47 MB binary. HNSW vector search, git-like branching, time-travel queries, AES-256-GCM encryption, built-in BaaS layer (Auth, REST API, Realtime).

Use your existing clients (psql, mysql), RESTful HTTP, drivers (psycopg2, mysql-connector, node-postgres, JDBC), and ORMs (SQLAlchemy, Prisma, Drizzle, Hibernate, GORM) — zero migration required. Existing .sqlite files import via a bundled converter.

Install

# npm (cross-platform, auto-downloads binary)
npx heliosdb start

# Homebrew (macOS / Linux)
brew install dimensigon/tap/heliosdb-nano

# Docker
docker run -p 5432:5432 -p 3306:3306 -p 8080:8080 heliosdb/nano:latest

# Binary release
curl -L https://github.com/Dimensigon/HDB-HeliosDB-Nano/releases/latest/download/heliosdb-nano-$(uname -m)-$(uname -s | tr A-Z a-z).tar.gz | tar xz

Start the Server

# Persistent, all three protocols
heliosdb-nano start --data-dir ./mydata --mysql

# In-memory (great for dev/test)
heliosdb-nano start --memory --mysql

# With auth and TLS
heliosdb-nano start --data-dir ./mydata --mysql \
  --auth scram-sha-256 --password s3cret \
  --tls-cert cert.pem --tls-key key.pem

# Same-host / embedded mode — Unix sockets (no TCP)
heliosdb-nano start --memory \
  --pg-socket-dir /tmp \
  --mysql --mysql-socket /tmp/heliosdb-mysql.sock
# then: psql -h /tmp  or  mysql --socket=/tmp/heliosdb-mysql.sock

Three servers start on one process:

Triple Compatibility — Same Data, Any Client

Start the server once, then connect from any of the three interfaces. They all read and write the same tables.

Interactive REPL (zero setup)

$ heliosdb-nano repl --data-dir ./mydata
heliosdb> CREATE TABLE products (id SERIAL PRIMARY KEY, name TEXT, price DECIMAL(10,2));
OK
heliosdb> INSERT INTO products (name, price) VALUES ('Widget', 9.99), ('Gadget', 19.99);
INSERT 2
heliosdb> SELECT * FROM products WHERE price < 15;
 id |  name  | price
----+--------+-------
  1 | Widget |  9.99
(1 row)

PostgreSQL Client (psql)

$ psql -h 127.0.0.1 -p 5432 -U postgres
psql (16.0, server HeliosDB Nano 3.13.0)
postgres=# INSERT INTO products (name, price) VALUES ('Gizmo', 29.99);
INSERT 0 1
postgres=# SELECT COUNT(*) FROM products;
 count
-------
     3

MySQL Client (mysql)

$ mysql -h 127.0.0.1 -P 3306 -u root
Server version: 8.0.35-HeliosDB-Nano
mysql> SELECT * FROM products WHERE name LIKE 'G%';
+----+--------+-------+
| id | name   | price |
+----+--------+-------+
|  2 | Gadget | 19.99 |
|  3 | Gizmo  | 29.99 |
+----+--------+-------+
mysql> INSERT INTO products (name, price) VALUES ('Gear', 39.99);
Query OK, 1 row affected

REST API (curl)

# Query
$ curl "http://localhost:8080/rest/v1/products?price=lt.50&select=id,name,price"
[{"id":1,"name":"Widget","price":"9.99"},{"id":2,"name":"Gadget","price":"19.99"}, ...]

# Insert
$ curl -X POST http://localhost:8080/rest/v1/products \
    -H 'Content-Type: application/json' \
    -d '{"name":"Gear 2","price":49.99}'

# Interactive API explorer (Swagger UI)
$ open http://localhost:8080/docs

Vector Search

Native HNSW indexes — no extensions, no separate vector database.

-- From any client (psql / mysql / REPL):
CREATE TABLE docs (
    id SERIAL PRIMARY KEY,
    title TEXT,
    embedding VECTOR(1536)
);

CREATE INDEX ON docs USING hnsw (embedding vector_cosine_ops);

INSERT INTO docs (title, embedding)
VALUES ('Intro', '[0.1, 0.2, 0.3, ...]');

-- k-NN search
SELECT title, embedding <-> '[0.15, 0.25, ...]' AS distance
FROM docs
ORDER BY distance
LIMIT 10;

Distance operators: <-> (cosine), <~> (L2), <#> (inner product).

Via REST:

curl -X POST http://localhost:8080/api/vectors/search \
    -H 'Content-Type: application/json' \
    -d '{"collection":"docs","query":[0.15,0.25],"k":5,"metric":"cosine"}'

Full-Text Search

PostgreSQL-compatible FTS surface — no extensions, backed by built-in BM25:

-- Native tsvector / tsquery / @@ / ts_rank_cd:
SELECT title, ts_rank_cd(to_tsvector(body), to_tsquery('heliosdb')) AS rank
FROM articles
WHERE to_tsvector(body) @@ to_tsquery('heliosdb')
ORDER BY rank DESC
LIMIT 10;

-- Persistent tsvector column + GIN-style DDL:
CREATE TABLE articles (id SERIAL PRIMARY KEY, body TEXT, body_tsv TSVECTOR);
CREATE INDEX articles_body_fts ON articles USING gin (body_tsv);

-- Hybrid search (FTS + vector) in one query:
SELECT id, text,
       0.7 * (1.0 - (embedding <=> $1::vector))
     + 0.3 * ts_rank_cd(to_tsvector(text), plainto_tsquery($2)) AS score
FROM chunks
ORDER BY score DESC LIMIT 10;

Scope and honest limitations: see docs/compatibility/fts.md.

Pagination — Constant-Time at Depth

Deep LIMIT … OFFSET runs in ~30 µs regardless of offset, up to 334× faster than PostgreSQL 13 for 100k-row tables. Top-K over Sort, storage-level OFFSET skip, and keyset (WHERE (col, id) < ($1, $2)) are all native.

See pagination-performance.html for measured numbers and reproduction recipe.

Git-Like Branching

Isolated copy-on-write branches for dev, test, and A/B experiments.

CREATE BRANCH staging FROM main;
USE BRANCH staging;

-- Changes here are invisible to main
INSERT INTO products (name, price) VALUES ('Test', 0.01);

MERGE BRANCH staging INTO main;
DROP BRANCH staging;

Time-Travel Queries

-- As of a timestamp
SELECT * FROM products AS OF TIMESTAMP '2026-04-01 12:00:00';

-- As of a transaction
SELECT * FROM products AS OF TRANSACTION 12345;

Built-in Backend-as-a-Service

Self-hosted Supabase/Firebase alternative — Auth, REST, Realtime, RLS in the same binary:

# Sign up
curl -X POST http://localhost:8080/auth/v1/signup \
    -H 'Content-Type: application/json' \
    -d '{"email":"alice@example.com","password":"s3cret"}'

# Google OAuth redirect
open http://localhost:8080/auth/v1/authorize?provider=google

# Realtime subscriptions (WebSocket)
wscat -c ws://localhost:8080/realtime/v1/websocket

RLS is automatic on REST endpoints via JWT claims. See vs-supabase.

ORM & Driver Compatibility

WordPress runs natively with standard wpdb — no drop-in required.

Data Types

All PostgreSQL types plus MySQL type aliases (automatically translated):

Features at a Glance

• Full SQL: JOINs, CTEs, window functions, subqueries, set operations, aggregates, CASE
• PL/pgSQL: Stored procedures and functions
• JSONB: ->, ->>, @>, ? operators
• Full-text search: tsvector, tsquery, @@, ts_rank_cd, CREATE INDEX ... USING gin (see FTS scope)
• Keyset pagination: row-constructor comparison WHERE (col, id) < ($1, $2); top-K sort; constant-time deep OFFSET
• Foreign keys: CASCADE, SET NULL, RESTRICT
• Triggers: BEFORE/AFTER INSERT/UPDATE/DELETE
• Row-Level Security: Per-tenant data isolation via policies
• EXPLAIN: Cost-based optimizer, ANALYZE, JSON/XML/YAML output
• Code-graph (opt-in, --features code-graph): tree-sitter-backed AST index + lsp_definition / lsp_references / lsp_call_hierarchy / lsp_hover as Rust API & SQL table functions — see code-graph overview
• Backup/Restore: Compressed dumps (zstd/gzip/brotli)
• Import/Export: CSV, JSON, JSONL, Parquet, Arrow, SQL
• Audit logging: Tamper-proof trail (SHA-256 checksums)
• Encryption: AES-256-GCM TDE, FIPS 140-3 mode
• Unix domain socket listeners for both PostgreSQL (--pg-socket-dir /tmp) and MySQL (--mysql-socket /tmp/heliosdb.sock) — PHP mysqli / WordPress embedded-mode and libpq defaults work out of the box

Architecture

High Availability

Warm standby is enabled by default — no feature flag needed. Just pass the replication flags at startup:

# Primary
heliosdb-nano start --data-dir ./data --replication-role primary \
  --standby-hosts 10.0.0.2:5433,10.0.0.3:5433

# Standby
heliosdb-nano start --data-dir ./data --replication-role standby \
  --primary-host 10.0.0.1:5433

Optional HA features (opt-in at compile time):

cargo build --release --features ha-full    # everything

Connection Routing & Load Balancing

For production deployments with multiple HeliosDB Nano instances, put HeliosProxy in front — a standalone binary providing:

• Read/write splitting across primary + standbys
• Automatic failover with transaction replay (Oracle TAF-style)
• Connection pooling
• Health checks + circuit breakers
• TLS termination

Recommended Production Setup

           ┌────────────────┐
    psql ─▶│                │──▶ HeliosDB Nano (primary, read+write)
   mysql ─▶│  HeliosProxy   │──▶ HeliosDB Nano (standby, read-only)
    curl ─▶│                │──▶ HeliosDB Nano (standby, read-only)
           └────────────────┘
              port 5432/3306/8080

1. Deploy 1 primary + 2 standbys (Fly.io / Render / Docker Swarm)
2. HeliosProxy in front for routing + failover
3. Automatic failover on primary death (< 5 s typical)
4. Readonly queries load-balanced across standbys

Deploy

Embedded Library (Rust)

For in-process use (no network, no daemon), add the crate as a dependency:

[dependencies]
heliosdb-nano = "3.13"

See the Rust API guide for embedded usage and the examples/ directory for working code.

Building from Source

The heliosdb-nano binary builds with cargo build --release. Default features are encryption + vector-search + ring-crypto + ha-tier1 — covers most embedded and single-node-server cases. Run cargo info heliosdb-nano (or cargo metadata --no-deps --format-version 1 | jq '.packages[0].features') for the live list. Recipes for the non-obvious combinations:

# Default build — embedded + Postgres/MySQL wire + warm-standby HA.
cargo build --release

# Code-graph + MCP server (matches what heliosdb-codekb-mcp links).
# Adds tree-sitter parsers, _hdb_code_* tables, lsp_* APIs, and the
# JSON-RPC dispatcher for stdio / HTTP / WebSocket / SSE clients.
cargo build --release --features "code-graph,graph-rag,mcp-endpoint"

# In-process embedder (no external HTTP service for embeddings).
# Pulls fastembed-rs + ORT — adds ~30 MB to the binary.
cargo build --release --features "code-graph,code-embed"

# FIPS 140-3 compliant crypto (AWS-LC FIPS Cert #4816, SHA-256, PBKDF2).
# `--no-default-features` is required to swap out ring-crypto.
cargo build --release --no-default-features \
  --features "fips,encryption,vector-search,ha-tier1"

# Full HA bundle — multi-primary + sharding + dedup + branch replication.
cargo build --release --features "ha-full"

SDKs & Integrations

Official client SDKs (Go, Python, TypeScript, Rust) and platform integrations (VS Code, Zapier, n8n, Retool, Make, AutoGen) live in a shared repository:

heliosdb-sdks — works with all HeliosDB editions.

# JavaScript / TypeScript (Supabase-compatible fluent API)
npm install @heliosdb/client

import { createClient } from '@heliosdb/client'
const db = createClient('http://localhost:8080', 'anon-key')
const { data } = await db.from('products').select('*').lt('price', 50)

Agentic Operations (Claude Code, Codex CLI, MCP-aware tools)

HeliosDB-Nano ships an agentic-operations skill catalogue — 17 SKILL.md files that give an LLM-driven coding agent a full A→Z catalogue of "verbs" for operating the database (install, connect, schema, DML, transactions, branches, time-travel, backup, vector, code-graph, graph-rag, MCP, server, deploy, observability, migrate). For Codex / generic agents the same content is aggregated at AGENTS.md at the project root.

# After git clone, Claude Code automatically picks up .claude/skills/ in this project.

# To install globally (~/.claude/skills/) so they apply in any project:
bash scripts/install-agent-skills.sh                # copy (default, frozen snapshot)
bash scripts/install-agent-skills.sh --symlink      # symlink (live updates)

Existing ~/.claude/skills/heliosdb-nano-* directories are backed up to *.bak.<unix-ts> before being overwritten in either mode.

Lookups: .claude/skills/_index/verb-map.md (every CLI flag / REPL meta-command / public Rust API method / MCP tool) · .claude/skills/_index/feature-matrix.md (cargo feature ↔ skill).

Documentation

• Getting Started
• API Explorer (Swagger UI) — when running locally
• vs Supabase
• vs Firebase
• vs PostgreSQL
• vs SQLite
• Migrate from MySQL

License

Apache-2.0 — Apache License, Version 2.0