beaver-db 0.24.5

Fast, embedded, and multi-modal DB based on SQLite for AI-powered applications.

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A fast, single-file, multi-modal database for Python, built with the standard sqlite3 library.

beaver is the Backend for Embedded, All-in-one Vector, Entity, and Relationship storage. It's a simple, local, and embedded database designed to manage complex, modern data types without requiring a database server, built on top of SQLite.

If you like beaver's minimalist, no-bullshit philosophy, check out castor for an equally minimalistic approach to task orchestration.

Design Philosophy

beaver is built with a minimalistic philosophy for small, local use cases where a full-blown database server would be overkill.

• Minimalistic: The core library has minimal dependencies (numpy, rich, typer). The REST server and client are available as an optional feature.
• Schemaless: Flexible data storage without rigid schemas across all modalities.
• Synchronous, Multi-Process, and Thread-Safe: Designed for simplicity and safety in multi-threaded and multi-process environments.
• Built for Local Applications: Perfect for local AI tools, RAG prototypes, chatbots, and desktop utilities that need persistent, structured data without network overhead.
• Fast by Default: It's built on SQLite, which is famously fast and reliable for local applications. Vector search is a built-in feature accelerated by a multi-process-safe, in-memory numpy index.
• Standard Relational Interface: While beaver provides high-level features, you can always use the same SQLite file for normal relational tasks with standard SQL.

Core Features

• Sync/Async High-Efficiency Pub/Sub: A powerful, thread and process-safe publish-subscribe system for real-time messaging with a fan-out architecture. Sync by default, but with an as_async wrapper for async applications.
• Namespaced Key-Value Dictionaries: A Pythonic, dictionary-like interface for storing any JSON-serializable object within separate namespaces with optional TTL for cache implementations.
• Pythonic List Management: A fluent, Redis-like interface for managing persistent, ordered lists.
• Persistent Priority Queue: A high-performance, persistent priority queue perfect for task orchestration across multiple processes. Also with optional async support.
• Inter-Process Locking: A robust, deadlock-proof, and fair (FIFO) distributed lock (db.lock()) to coordinate multiple processes and prevent race conditions.
• Time-Indexed Log for Monitoring: A specialized data structure for structured, time-series logs. Query historical data by time range or create a live, aggregated view of the most recent events for real-time dashboards.
• Simple Blob Storage: A dictionary-like interface for storing medium-sized binary files (like PDFs or images) directly in the database, ensuring transactional integrity with your other data.
• High-Performance Vector Storage & Search: Store vector embeddings and perform fast, multi-process-safe linear searches using an in-memory numpy-based index.
• Full-Text and Fuzzy Search: Automatically index and search through document metadata using SQLite's powerful FTS5 engine, enhanced with optional fuzzy search for typo-tolerant matching.
• Knowledge Graph: Create relationships between documents and traverse the graph to find neighbors or perform multi-hop walks.
• Single-File & Portable: All data is stored in a single SQLite file, making it incredibly easy to move, back up, or embed in your application.
• Built-in REST API Server (Optional): Instantly serve your database over a RESTful API with automatic OpenAPI documentation using FastAPI.
• Full-Featured CLI Client: Interact with your database directly from the command line for administrative tasks and data exploration.
• Optional Type-Safety: Although the database is schemaless, you can use a minimalistic typing system for automatic serialization and deserialization that is Pydantic-compatible out of the box.
• Data Export & Backups: Dump any dictionary, list, collection, queue, blob, or log structure to a portable JSON file with a single .dump() command.

How Beaver is Implemented

BeaverDB is architected as a set of targeted wrappers around a standard SQLite database. The core BeaverDB class manages a single connection to the SQLite file and initializes all the necessary tables for the various features.

When you call a method like db.dict("my_dict") or db.collection("my_docs"), you get back a specialized manager object (DictManager, CollectionManager, etc.) that provides a clean, Pythonic API for that specific data modality. These managers translate the simple method calls (e.g., my_dict["key"] = "value") into the appropriate SQL queries, handling all the complexity of data serialization, indexing, and transaction management behind the scenes. This design provides a minimal and intuitive API surface while leveraging the power and reliability of SQLite.

The vector store in BeaverDB is designed for simplicity and multi-process safety, using an in-memory numpy index with a log-based synchronization mechanism. Here's a look at the core ideas behind its implementation:

• In-Memory Delta-Index System: Each process maintains its own in-memory numpy index. This index is split into two-tiers to balance fast writes with read efficiency:
• Base Index (N-matrix): A numpy array holding the compacted, main set of vectors. This is loaded from disk once.
• Delta Index (k-matrix): A small, in-memory numpy array holding all new vectors that have been added since the last compaction.
• Tombstones: A set of deleted vector IDs that are filtered out at search time.
• Fast, Log-Based Sync: All vector additions (index()) and deletions (drop()) are O(1) writes to a central SQLite log table (_vector_change_log). When another process performs a search, it first checks this log and performs a fast O(k) "delta-sync" to update its in-memory k-matrix and tombstones, rather than re-loading the entire N-matrix.
• Automatic Compaction: When the delta index (k-matrix) grows too large, a compaction process is triggered to rebuild the main N-matrix from the database and clear the log. This ensures search performance remains fast over time.

This delta-index approach allows BeaverDB to provide a vector search experience that has extremely fast O(1) writes and O(k) cross-process synchronization, sacrificing O(log N) search time for a simpler, dependency-free O(N+k) linear scan. This aligns with the "simplicity-first" philosophy of the library.

Installation

Install the core library:

pip install beaver-db

This includes numpy (for vector search) and rich/typer (for the CLI).

To include optional features, you can install them as extras:

# For the REST API server and client
pip install "beaver-db[remote]"

# To install all optional features at once
pip install "beaver-db[full]"

Running with Docker

For a fully embedded and lightweight solution, you can run the BeaverDB REST API server using Docker. This is the easiest way to get a self-hosted instance up and running.

docker pull ghcr.io/syalia-srl/beaver:latest
docker run -p 8000:8000 -v $(pwd)/data:/app ghcr.io/syalia-srl/beaver

This command will start the BeaverDB server, and your database file will be stored in the data directory on your host machine. You can access the API at http://localhost:8000.

Quickstart

Get up and running in 30 seconds. This example showcases a dictionary, a list, and full-text search in a single script.

from beaver import BeaverDB, Document

# 1. Initialize the database
db = BeaverDB("data.db")

# 2. Use a namespaced dictionary for app configuration
config = db.dict("app_config")
config["theme"] = "dark"
print(f"Theme set to: {config['theme']}")

# 3. Use a persistent list to manage a task queue
tasks = db.list("daily_tasks")
tasks.push("Write the project report")
tasks.push("Deploy the new feature")
print(f"First task is: {tasks[0]}")

# 4. Use a collection for document storage and search
articles = db.collection("articles")
doc = Document(
    id="sqlite-001",
    content="SQLite is a powerful embedded database ideal for local apps."
)
articles.index(doc)

# Perform a full-text search
results = articles.match(query="database")
top_doc, rank = results[0]
print(f"FTS Result: '{top_doc.content}'")

db.close()

Built-in Server and CLI

Beaver comes with a built-in REST API server and a powerful, full-featured command-line client, allowing you to interact with your database without writing any code.

REST API Server

You can instantly expose all of your database's functionality over a RESTful API. This is perfect for building quick prototypes, microservices, or for interacting with your data from other languages.

1. Start the server

# Start the server for your database file
beaver serve --database data.db --port 8000

This starts a FastAPI server. You can now access the interactive API documentation at http://127.0.0.1:8000/docs.

2. Interact with the API

Here are a couple of examples using curl:

# Set a value in the 'app_config' dictionary
curl -X PUT http://127.0.0.1:8000/dicts/app_config/api_key \
     -H "Content-Type: application/json" \
     -d '"your-secret-api-key"'

# Get the value back
curl http://127.0.0.1:8000/dicts/app_config/api_key
# Output: "your-secret-api-key"

Full-Featured CLI Client

The CLI client allows you to call any BeaverDB method directly from your terminal. Built with typer and rich, it provides a user-friendly, task-oriented interface with beautiful output.

# Get a value from a dictionary
beaver dict app_config get theme

# Set a value (JSON is automatically parsed)
beaver dict app_config set user '{"name": "Alice", "id": 123}'

# Push an item to a list
beaver list daily_tasks push "Review PRs"

# Watch a live, aggregated dashboard of a log
beaver log system_metrics watch

# Run a script protected by a distributed lock
beaver lock my-cron-job run bash -c 'run_daily_report.sh'

Data Export for Backups

All data structures (dict, list, collection, queue, log, and blobs) support a .dump() method for easy backups and migration. You can either write the data directly to a JSON file or get it as a Python dictionary.

import json
from beaver import BeaverDB

db = BeaverDB("my_app.db")
config = db.dict("app_config")

# Add some data
config["theme"] = "dark"
config["user_id"] = 456

# Dump the dictionary's contents to a JSON file
with open("config_backup.json", "w") as f:
    config.dump(f)

# 'config_backup.json' now contains:
# {
#   "metadata": {
#     "type": "Dict",
#     "name": "app_config",
#     "count": 2,
#     "dump_date": "2025-11-02T09:05:10.123456Z"
#   },
#   "items": [
#     {"key": "theme", "value": "dark"},
#     {"key": "user_id", "value": 456}
#   ]
# }

# You can also get the dump as a Python object
dump_data = config.dump()

You can also use the CLI to dump data:

beaver --database data.db collection my_documents dump > my_documents.json

Things You Can Build with Beaver

Here are a few ideas to inspire your next project, showcasing how to combine Beaver's features to build powerful local applications.

1. AI Agent Task Management

Use a persistent priority queue to manage tasks for an AI agent. This ensures the agent always works on the most important task first, even if the application restarts.

tasks = db.queue("agent_tasks")

# Tasks are added with a priority (lower is higher)
tasks.put({"action": "summarize_news"}, priority=10)
tasks.put({"action": "respond_to_user"}, priority=1)
tasks.put({"action": "run_backup"}, priority=20)

# The agent retrieves the highest-priority task
next_task = tasks.get() # -> Returns the "respond_to_user" task
print(f"Agent's next task: {next_task.data['action']}")

2. User Authentication and Profile Store

Use a namespaced dictionary to create a simple and secure user store. The key can be the username, and the value can be a dictionary containing the hashed password and other profile information.

users = db.dict("user_profiles")

# Create a new user
users["alice"] = {
    "hashed_password": "...",
    "email": "[e-mail]",
    "permissions": ["read", "write"]
}

# Retrieve a user's profile
alice_profile = users.get("alice")

3. Chatbot Conversation History

A persistent list is perfect for storing the history of a conversation. Each time the user or the bot sends a message, just push it to the list. This maintains a chronological record of the entire dialogue.

chat_history = db.list("conversation_with_user_123")

chat_history.push({"role": "user", "content": "Hello, Beaver!"})
chat_history.push({"role": "assistant", "content": "Hello! How can I help you today?"})

# Retrieve the full conversation
for message in chat_history:
    print(f"{message['role']}: {message['content']}")

4. Build a RAG (Retrieval-Augmented Generation) System

Combine vector search and full-text search to build a powerful RAG pipeline for your local documents. The vector search uses a multi-process-safe, in-memory numpy index that supports incremental additions without downtime.

# Get context for a user query like "fast python web frameworks"
vector_results = [doc for doc, _ in docs.search(vector=query_vector)]
text_results = [doc for doc, _ in docs.match(query="python web framework")]

# Combine and rerank for the best context
from beaver.collections import rerank
best_context = rerank(vector_results, text_results, weights=[0.6, 0.4])

5. Caching for Expensive API Calls

Leverage a dictionary with a TTL (Time-To-Live) to cache the results of slow network requests. This can dramatically speed up your application and reduce your reliance on external services.

api_cache = db.dict("external_api_cache")

# Check the cache first
response = api_cache.get("weather_new_york")
if response is None:
    # If not in cache, make the real API call
    response = make_slow_weather_api_call("New York")
    # Cache the result for 1 hour
    api_cache.set("weather_new_york", response, ttl_seconds=3600)

6. Real-time Event-Driven Systems

Use the high-efficiency pub/sub system to build applications where different components react to events in real-time. This is perfect for decoupled systems, real-time UIs, or monitoring services.

# In one process or thread (e.g., a monitoring service)
system_events = db.channel("system_events")
system_events.publish({"event": "user_login", "user_id": "alice"})

# In another process or thread (e.g., a UI updater or logger)
with db.channel("system_events").subscribe() as listener:
    for message in listener.listen():
        print(f"Event received: {message}")
        # >> Event received: {'event': 'user_login', 'user_id': 'alice'}

7. Storing User-Uploaded Content

Use the simple blob store to save files like user avatars, attachments, or generated reports directly in the database. This keeps all your data in one portable file.

attachments = db.blobs("user_uploads")

# Store a user's avatar
with open("avatar.png", "rb") as f:
    avatar_bytes = f.read()

attachments.put(
    key="user_123_avatar.png",
    data=avatar_bytes,
    metadata={"mimetype": "image/png"}
)

# Retrieve it later
avatar = attachments.get("user_123_avatar.png")

8. Real-time Application Monitoring

Use the time-indexed log to monitor your application's health in real-time. The live() method provides a continuously updating, aggregated view of your log data, perfect for building simple dashboards directly in your terminal.

from datetime import timedelta
import statistics

logs = db.log("system_metrics")

def summarize(window):
    values = [log.get("value", 0) for log in window]
    return {"mean": statistics.mean(values), "count": len(values)}

live_summary = logs.live(
    window=timedelta(seconds=10),
    period=timedelta(seconds=1),
    aggregator=summarize
)

for summary in live_summary:
    print(f"Live Stats (10s window): Count={summary['count']}, Mean={summary['mean']:.2f}")

9. Coordinate Distributed Web Scrapers

Run multiple scraper processes in parallel and use db.lock() to coordinate them. You can ensure only one process refreshes a shared API token or sitemap, preventing race conditions and rate-limiting.

import time

scrapers_state = db.dict("scraper_state")

last_refresh = scrapers_state.get("last_sitemap_refresh", 0)
if time.time() - last_refresh > 3600: # Only refresh once per hour
    try:
        # Try to get a lock to refresh the shared sitemap, but don't wait long
        with db.lock("refresh_sitemap", timeout=1):
            # We got the lock. Check if it's time to refresh.
            print(f"PID {os.getpid()} is refreshing the sitemap...")
            scrapers_state["sitemap"] = ["/page1", "/page2"] # Your fetch_sitemap()
            scrapers_state["last_sitemap_refresh"] = time.time()

    except TimeoutError:
        # Another process is already refreshing, so we can skip
        print(f"PID {os.getpid()} letting other process handle refresh.")

# All processes can now safely use the shared sitemap
sitemap = scrapers_state.get("sitemap")
# ... proceed with scraping ...

Type-Safe Data Models

For enhanced data integrity and a better developer experience, BeaverDB supports type-safe operations for all modalities. By associating a model with these data structures, you get automatic serialization and deserialization, complete with autocompletion in your editor.

This feature is designed to be flexible and works seamlessly with two kinds of models:

• Pydantic Models: If you're already using Pydantic, your BaseModel classes will work out of the box.
• Lightweight beaver.Model: For a zero-dependency solution, you can inherit from the built-in beaver.Model class, which is a standard Python class with serialization methods automatically included.

Here’s a quick example of how to use it:

from beaver import BeaverDB, Model

# Inherit from beaver.Model for a lightweight, dependency-free model
class User(Model):
    name: str
    email: str

db = BeaverDB("user_data.db")

# Associate the User model with a dictionary
users = db.dict("user_profiles", model=User)

# BeaverDB now handles serialization automatically
users["alice"] = User(name="Alice", email="[e-mail]")

# The retrieved object is a proper instance of the User class
retrieved_user = users["alice"]
# Your editor will provide autocompletion here
print(f"Retrieved: {retrieved_user.name}")

In the same way you can have typed message payloads in db.channel, typed metadata in db.blobs, and custom document types in db.collection, as well as custom types in lists and queues.

Basically everywhere you can store or get some object in BeaverDB, you can use a typed version adding model=MyClass to the corresponding wrapper methond in BeaverDB and enjoy first-class type safety and inference.

Documentation

For a complete API reference, in-depth guides, and more examples, please visit the official documentation at:

https://syalia.com/beaver

Also, check the examples folder for a comprehensive list of working examples using beaver.

Roadmap

beaver is roughly feature-complete, but there are still some features and improvements planned for future releases, mostly directed to improving developer experience.

If you think of something that would make beaver more useful for your use case, please open an issue and/or submit a pull request.

License

This project is licensed under the MIT License.