KalamDB Backend

Rust-based messaging server with RocksDB storage and REST API.

🚀 Quick Start

Prerequisites

First time setting up? See our comprehensive setup guides:

• 📘 Development Setup Guide - Complete installation for Windows/macOS/Linux
• 🚀 Quick Start - Get running in 10 minutes

Requirements:

• Rust 1.75 or later
• LLVM/Clang (required for RocksDB compilation)
• C++ Compiler (Visual Studio Build Tools on Windows, Xcode CLI on macOS, build-essential on Linux)

Build

cd backend
cargo build

Note: First build takes 10-20 minutes as it compiles RocksDB, Arrow, and Parquet from source.

Known Issue: If you encounter chrono/arrow-arith compilation errors, see KNOWN_ISSUES.md for the fix.

Configure

Copy the example configuration and customize it:

cp server.example.toml server.toml
# Edit server.toml with your settings

Run

# API-only (faster compile). Add `--features embedded-ui` to serve the admin UI.
cargo run

The server will start on http://127.0.0.1:2900 by default.

New Features (Phase 006)

API Key Authentication

Create users with auto-generated API keys for secure access:

# Create a user with API key
cargo run --bin kalamdb-server -- create-user --name "demo-user" --role "user"

# Output:
# ✅ User created successfully!
# API Key: 550e8400-e29b-41d4-a716-446655440000

Use the API key with the X-API-KEY header:

curl -X POST http://localhost:2900/sql \
  -H "Content-Type: application/json" \
  -H "X-API-KEY: 550e8400-e29b-41d4-a716-446655440000" \
  -d '{"query": "SELECT * FROM todos"}'

Note: Localhost (127.0.0.1) connections bypass API key requirement for development convenience.

Soft Delete

User table rows are now soft-deleted (marked as deleted) instead of being physically removed:

-- Delete row (soft delete)
DELETE FROM my_table WHERE id = 5;

-- Row is hidden from SELECT queries
SELECT * FROM my_table;  -- Won't show id=5

-- Admin can view deleted rows (future feature)
SELECT * FROM my_table INCLUDE DELETED;

Benefits:

• Data recovery capability
• Audit trail preservation
• Safer than hard delete

Docker Deployment

Deploy KalamDB in a production-ready Docker container:

cd docker/build
docker build -f Dockerfile -t jamals86/kalamdb:latest ../..
cd ../run/single
docker-compose up -d

See docker/README.md for complete deployment guide.

Environment Variable Configuration

Override any server.toml setting with environment variables:

KALAMDB_SERVER_PORT=9000 \
KALAMDB_LOG_LEVEL=debug \
KALAMDB_LOG_FORMAT=json \
cargo run

Common environment overrides:

• KALAMDB_SERVER_PORT → [server].port
• KALAMDB_LOG_LEVEL → [logging].level
• KALAMDB_LOG_FORMAT → [logging].format
• KALAMDB_LOGS_DIR → [logging].logs_path
• KALAMDB_LOG_TO_CONSOLE → [logging].log_to_console
• KALAMDB_DATA_DIR → [storage].data_path

For the full logging and traceability guide, including Docker and OTLP examples, see:

• https://kalamdb.org/docs/server/configurations/logging

Client SDKs

KalamDB provides official SDKs for multiple languages in link/sdks/:

TypeScript/JavaScript SDK (link/sdks/typescript/client/):

• 📦 Published as @kalamdb/client on npm
• 🔧 37 KB WASM module with full TypeScript types
• ✅ 14 passing tests, comprehensive API documentation
• 🌐 Works in browsers and Node.js

Usage in Examples:

{
  "dependencies": {
    "@kalamdb/client": "file:../../link/sdks/typescript/client"
  }
}

Important: Examples MUST use SDKs as dependencies, not create mock implementations. See SDK Integration Guide for architecture details.

See link/README.md for complete SDK documentation.

Development

Project Structure

backend/
├── Cargo.toml                    # Workspace configuration
├── server.example.toml           # Example configuration
├── crates/
│   ├── kalamdb-core/            # Core storage library
│   ├── kalamdb-api/             # REST API library
│   └── kalamdb-server/          # Main server binary
└── tests/                        # Integration tests

Running Tests

# Run all tests
cargo test

# Run specific test
cargo test test_message_storage

# Run integration tests only
cargo test --test '*'

# Run with output
cargo test -- --nocapture

Code Quality

# Check for errors
cargo check

# Run clippy (linter)
cargo clippy

# Format code
cargo fmt

# Build optimized release
cargo build --release

Configuration

See server.example.toml for all available configuration options:

• Server: Host, port, worker threads
• Storage: RocksDB path, WAL settings, compression
• Limits: Message size, query limits
• Logging: Log level, file path, format
• Performance: Timeouts, connection limits

API Endpoints

POST /api/v1/messages

Insert a new message

Request:

{
  "conversation_id": "conv_123",
  "from": "user_alice",
  "content": "Hello, world!",
  "metadata": {"role": "user"}
}

Response:

{
  "msg_id": 1234567890,
  "status": "stored"
}

POST /api/v1/query

Query messages

Request:

{
  "conversation_id": "conv_123",
  "limit": 50
}

Response:

{
  "messages": [...],
  "count": 50,
  "has_more": false
}

GET /health

Health check endpoint

Response:

{
  "status": "healthy",
  "version": "0.1.0"
}

Logging

Logs are written to the path specified in server.toml (default: ./logs/app.log).

Log levels: error, warn, info, debug, trace

To change log level:

[logging]
level = "debug"

Architecture

• kalamdb-core: Core storage engine with RocksDB wrapper, message models, and ID generation
• kalamdb-api: REST API handlers and routes using Actix-web
• kalamdb-server: Main binary that ties everything together

Current Status

Phase 1 Complete: Project structure and dependencies set up ✅

Phase 2 Next: Implement foundational components (config, logging, models, storage)

See specs/001-build-a-rust/tasks.md for the complete task list.

Known Issues & Troubleshooting

Arrow 52.2.0 + Chrono 0.4.40+ Conflict (RESOLVED)

If you encounter compilation errors with arrow-arith and chrono::quarter(), this has been fixed by pinning chrono to 0.4.39.

Verification:

# PowerShell (Windows)
pwsh -File scripts/verify-chrono-version.ps1

# Bash (Linux/macOS)
bash scripts/verify-chrono-version.sh

For details, see KNOWN_ISSUES.md.

License

Licensed under the Apache License, Version 2.0 (Apache-2.0). See ../LICENSE.txt and ../NOTICE.