Local Development Setup

Set up a Bknd local development environment from scratch.

Prerequisites

• Node.js 18+ or Bun 1.0+
• npm, yarn, pnpm, or bun package manager
• Terminal/command line access

When to Use UI Mode

• Browsing admin panel at http://localhost:3000/admin
• Exploring entities and data visually
• Testing auth flows manually

Note: Initial project setup requires CLI/code.

When to Use Code Mode

• Creating new Bknd project
• Configuring database connection
• Defining schema
• Running development server
• All initial setup tasks

Code Approach

Step 1: Create New Project (Interactive)

Quickest way to start:

# Interactive project creation
npx bknd create my-app

# Follow prompts:
# - Project name
# - Database type (SQLite recommended for local dev)
# - Include example schema?

This creates project structure with:

• bknd.config.ts - Main configuration
• package.json - Dependencies
• .env - Environment variables template

Step 2: Install Dependencies

cd my-app

# npm
npm install

# bun (faster)
bun install

# pnpm
pnpm install

Step 3: Run Development Server

# Default (port 3000, file-based SQLite)
npx bknd run

# In-memory database (fastest for prototyping, data lost on restart)
npx bknd run --memory

# Custom port
npx bknd run --port 8080

# Don't auto-open browser
npx bknd run --no-open

# Specify runtime explicitly
npx bknd run --server bun
npx bknd run --server node

Server starts at http://localhost:3000 with:

• API: /api/data/*, /api/auth/*, /api/media/*
• Admin UI: /admin

Alternative: Manual Setup

Step 1: Initialize Package

mkdir my-bknd-app && cd my-bknd-app
npm init -y
npm install bknd

Step 2: Create Config File

Create bknd.config.ts:

import type { CliBkndConfig } from "bknd";
import { em, entity, text, boolean } from "bknd";

// Define schema
const schema = em({
  todos: entity("todos", {
    title: text().required(),
    done: boolean(),
  }),
});

// Register types
type Database = (typeof schema)["DB"];
declare module "bknd" {
  interface DB extends Database {}
}

export default {
  app: (env) => ({
    connection: {
      url: env.DB_URL ?? "file:data.db",
    },
    schema,
  }),
} satisfies CliBkndConfig;

Step 3: Create Entry File (Optional)

For programmatic control, create index.ts:

import { serve } from "bknd/adapter/bun";
import { em, entity, text, boolean } from "bknd";

const schema = em({
  todos: entity("todos", {
    title: text().required(),
    done: boolean(),
  }),
});

serve({
  connection: { url: "file:data.db" },
  config: {
    data: schema.toJSON(),
  },
});

Run with:

# Bun
bun run index.ts

# Node (requires tsx or ts-node)
npx tsx index.ts

Runtime Adapters

Bun (Recommended for Speed)

import { serve } from "bknd/adapter/bun";

serve({
  connection: { url: "file:data.db" },
});

Node.js

import { serve } from "bknd/adapter/node";

serve({
  connection: { url: "file:data.db" },
});

Framework Integrations

Next.js:

// app/api/bknd/[[...bknd]]/route.ts
import { createHandler } from "bknd/adapter/nextjs";
export const { GET, POST, PUT, DELETE, PATCH } = createHandler(config);

Astro:

// src/pages/api/[...bknd].ts
import { createHandler } from "bknd/adapter/astro";
export const ALL = createHandler(config);

React Router (Remix):

// app/routes/api.$.tsx
import { createHandler } from "bknd/adapter/react-router";
export const loader = createHandler(config);
export const action = createHandler(config);

CLI Options Reference

Config File Detection

Bknd auto-detects config files (in order):

• bknd.config.ts
• bknd.config.js
• bknd.config.mjs
• bknd.config.cjs
• bknd.config.json

Project Structure

Recommended Layout

my-bknd-app/
├── bknd.config.ts      # Main configuration
├── bknd-types.d.ts     # Generated types (run: npx bknd types)
├── .env                # Environment variables
├── .dev.vars           # Dev-specific overrides (optional)
├── data.db             # SQLite file (auto-created)
├── uploads/            # Local media storage (if using local adapter)
└── package.json

Framework Integration Layout

my-nextjs-app/
├── app/
│   ├── api/
│   │   └── bknd/
│   │       └── [[...bknd]]/
│   │           └── route.ts
│   └── admin/
│       └── page.tsx
├── bknd.config.ts
├── bknd-types.d.ts
└── .env.local

Generate TypeScript Types

After defining schema, generate types for IDE support:

# Generate to bknd-types.d.ts (default)
npx bknd types

# Custom output
npx bknd types -o types/bknd.d.ts

# Print to console (debug)
npx bknd types --dump

Database Options for Local Dev

In-Memory (Ephemeral)

npx bknd run --memory

Data resets on server restart. Best for rapid prototyping.

File-Based SQLite (Persistent)

npx bknd run
# or explicitly:
npx bknd run --db-url "file:data.db"

Data persists in data.db file.

Reset Database

# Delete SQLite file for fresh start
rm data.db

# Then restart server
npx bknd run

Hot Reload

Schema changes require server restart. Use watch mode:

# Bun
bun --watch index.ts

# Node with nodemon
npx nodemon --exec "npx bknd run"

Debug Commands

# Show internal paths
npx bknd debug paths

# Show all registered routes
npx bknd debug routes

# CLI help
npx bknd --help
npx bknd run --help

Verification

After setup, verify everything works:

1. Server running:

curl http://localhost:3000/api/data
# Should return entity list

2. Admin panel accessible: Open http://localhost:3000/admin in browser

3. Types generated:

npx bknd types
# Check bknd-types.d.ts created

Common Pitfalls

Config File Not Found

Problem: Config file could not be resolved error

Fix: Ensure config file exists with correct extension:

# Check file exists
ls bknd.config.*

# Or specify explicitly
npx bknd run -c ./bknd.config.ts

Port Already in Use

Problem: EADDRINUSE: address already in use

Fix: Use different port or kill existing process:

# Use different port
npx bknd run --port 3001

# Or find and kill process
lsof -i :3000
kill -9 <PID>

Database Permission Error

Problem: SQLITE_CANTOPEN: unable to open database file

Fix: Ensure write permissions in directory:

# Check permissions
ls -la

# Fix permissions
chmod 755 .

TypeScript Errors with em()

Problem: Type errors when using em() return value

Fix: Remember em() returns schema definition, not EntityManager:

// WRONG - em() is schema builder only
const em = em({ ... });
em.repo("posts").find();  // ERROR

// CORRECT - use api.data for queries
const api = new Api({ url: "http://localhost:3000" });
api.data.readMany("posts");

Bun Not Found

Problem: bun: command not found

Fix: Install Bun or use Node:

# Install Bun
curl -fsSL https://bun.sh/install | bash

# Or use Node runtime
npx bknd run --server node

Windows Path Issues

Problem: File paths not resolving on Windows

Fix: Use forward slashes:

// WRONG
connection: { url: "file:C:\\data\\my.db" }

// CORRECT
connection: { url: "file:C:/data/my.db" }
// or relative
connection: { url: "file:data.db" }

DOs and DON'Ts

DO:

• Use --memory flag for quick experiments
• Use file:data.db for persistent development
• Generate types after schema changes
• Commit bknd.config.ts to version control
• Use .env for environment-specific values

DON'T:

• Commit data.db to version control (add to .gitignore)
• Commit .env with secrets (use .env.example template)
• Use in-memory database when you need data persistence
• Forget to restart server after schema changes
• Try to use em() result as EntityManager

Related Skills

• bknd-env-config - Configure environment variables
• bknd-create-entity - Create entities in your schema
• bknd-client-setup - Set up SDK in frontend
• bknd-debugging - Debug common issues
• bknd-deploy-hosting - Deploy to production