docs: add CONTRIBUTING.md with dev setup, project structure, and contribution guidelines

Co-authored-by: Amp <amp@ampcode.com>
Amp-Thread-ID: https://ampcode.com/threads/T-019ca575-cf6e-7388-9bd4-6ddd4c27609c

CONTRIBUTING.md

@@ -0,0 +1,267 @@
+# Contributing to bknd
+
+Thank you for your interest in contributing to bknd. This guide will help you get started, understand the codebase, and submit contributions that align with the project's direction.
+
+## Table of Contents
+
+- [Before You Start](#before-you-start)
+- [Important Resources](#important-resources)
+- [Development Setup](#development-setup)
+- [Project Structure](#project-structure)
+- [Understanding the Codebase](#understanding-the-codebase)
+- [Running Tests](#running-tests)
+- [Code Style](#code-style)
+- [Submitting Changes](#submitting-changes)
+- [AI-Generated Code](#ai-generated-code)
+- [Contributing to Documentation](#contributing-to-documentation)
+- [Reporting Bugs](#reporting-bugs)
+- [Getting Help](#getting-help)
+- [Contributors](#contributors)
+- [Maintainers](#maintainers)
+
+## Before You Start
+
+**Open a GitHub Issue before writing code.** This is the preferred way to propose any change. It lets maintainers and the community align on the approach before time is spent on implementation. If you have discussed a contribution in the [Discord server](https://discord.com/invite/952SFk8Tb8) instead, include a link to the relevant Discord thread in your pull request. Pull requests submitted without a corresponding issue or Discord discussion may be closed.
+
+**Unsolicited architectural changes will be closed.** The internal architecture of bknd is intentional. Refactors, restructuring, or changes to core patterns must be discussed and approved before any code is written.
+
+Contributions that are generally welcome (after opening an issue):
+
+- Bug fixes
+- New adapters, strategies, or storage backends
+- Documentation improvements
+- New examples
+- Test coverage improvements
+
+**A note on versioning**: bknd is pre-1.0 and under active development. Full backward compatibility is not guaranteed before v1.0.0. Contributors should be aware that APIs and internal interfaces may change between releases.
+
+## Important Resources
+
+- **Documentation**: https://docs.bknd.io
+- **Issue Tracker**: https://github.com/bknd-io/bknd/issues
+- **Discord**: https://discord.com/invite/952SFk8Tb8
+- **FAQ / Search**: https://www.answeroverflow.com/c/1308395750564302952
+
+## Development Setup
+
+### Prerequisites
+
+- Node.js 22.13 or higher
+- Bun 1.3.3
+
+### Getting Started
+
+1. Fork the repository and clone your fork.
+
+2. Install dependencies from the repo root:
+
+   ```bash
+   bun install
+   ```
+
+3. Navigate to the main app package:
+
+   ```bash
+   cd app
+   ```
+
+4. Copy the example environment file:
+
+   ```bash
+   cp .env.example .env
+   ```
+
+   The default `.env.example` includes a file-based SQLite database (`file:.db/dev.db`). You can change `VITE_DB_URL` to `:memory:` for an in-memory database instead.
+
+5. Start the dev server:
+
+   ```bash
+   bun run dev
+   ```
+
+   The dev server runs on `http://localhost:28623` using Vite with Hono.
+
+## Project Structure
+
+This is a Bun monorepo using workspaces. The vast majority of the code lives in `app/`.
+
+```
+bknd/
+  app/                    # Main "bknd" npm package (this is where most work happens)
+    src/
+      adapter/            # Runtime/framework adapters (node, bun, cloudflare, nextjs, astro, etc.)
+      auth/               # Authentication module (strategies, sessions, user pool)
+      cli/                # CLI commands
+      core/               # Shared utilities, event system, drivers, server helpers
+      data/               # Data module (entities, fields, relations, queries, schema)
+      flows/              # Workflow engine and tasks
+      media/              # Media module (storage adapters, uploads)
+      modes/              # Configuration modes (code, hybrid, db)
+      modules/            # Module system, MCP server, permissions framework
+      plugins/            # Built-in plugins (auth, data, cloudflare, dev)
+      ui/                 # All frontend code
+        client/           # TypeScript SDK and React hooks (exported as bknd/client)
+        elements/         # React components for auth/media (exported as bknd/elements)
+        (everything else) # Admin UI (exported as bknd/ui)
+      App.ts              # Central application orchestrator
+      index.ts            # Main package exports
+    __test__/             # Unit tests (mirrors src/ structure)
+    e2e/                  # End-to-end tests (Playwright)
+    build.ts              # Build script (tsup/esbuild)
+    build.cli.ts          # CLI build script
+  packages/               # Small satellite packages
+    cli/                  # Standalone CLI package (bknd-cli)
+    plasmic/              # Plasmic integration
+    postgres/             # Postgres helper
+    sqlocal/              # SQLocal helper
+  docs/                   # Documentation site (Next.js + Fumadocs, deployed to docs.bknd.io)
+  examples/               # Example projects across runtimes and frameworks
+  docker/                 # Docker configuration
+```
+
+## Understanding the Codebase
+
+### Path Aliases
+
+The project uses TypeScript path aliases defined in `app/tsconfig.json`. Imports like `core/utils`, `data/connection`, or `auth/authenticate` resolve to directories under `app/src/`. When reading source code, keep this in mind -- an import like `import { Connection } from "data/connection"` refers to `app/src/data/connection`, not an external package.
+
+### Module System
+
+bknd is built around four core modules, each with its own schema, API routes, and permissions:
+
+- **Data** -- entity definitions, field types, relations, queries (backed by Kysely)
+- **Auth** -- authentication strategies, sessions, user management
+- **Media** -- file storage with pluggable adapters (S3, Cloudinary, local filesystem, etc.)
+- **Flows** -- workflow automation and task execution
+
+These modules are managed by the `ModuleManager` (in `app/src/modules/`), which handles configuration, building, and lifecycle.
+
+### Adapter Pattern
+
+Adapters in `app/src/adapter/` allow bknd to run on different runtimes and frameworks. Each adapter provides the glue between bknd's Hono-based server and a specific environment (Node, Bun, Cloudflare Workers, Next.js, Astro, etc.).
+
+### Plugin System
+
+Plugins (in `app/src/plugins/`) hook into the app lifecycle via callbacks like `beforeBuild`, `onBuilt`, `onServerInit`, and `schema`. They can add entities, register routes, and extend behavior.
+
+### Build System
+
+The build is handled by a custom `app/build.ts` script using tsup (esbuild under the hood). It builds four targets in parallel:
+
+- **API** -- the core backend
+- **UI** -- the admin interface
+- **Elements** -- standalone React components
+- **Adapters** -- all runtime/framework adapters
+
+## Running Tests
+
+All test commands run from the `app/` directory.
+
+| Command | Runner | What it runs |
+|---|---|---|
+| `bun run test` | Bun test | Unit tests (`*.spec.ts` files) |
+| `bun run test:node` | Vitest | Node-specific tests (`*.vi-test.ts`, `*.vitest.ts`) |
+| `bun run test:e2e` | Playwright | End-to-end tests (`*.e2e-spec.ts` in `e2e/`) |
+| `bun run types` | TypeScript | Type checking (no emit) |
+
+CI runs both Bun and Node tests, with a Postgres 17 service for database integration tests.
+
+## Code Style
+
+The project uses **Biome** for formatting and linting.
+
+- 3-space indentation for JavaScript/TypeScript
+- 100-character line width
+- Spaces (not tabs)
+
+To format and lint, run from the repo root:
+
+```bash
+bunx biome format --write ./app
+bunx biome lint --changed --write ./app
+```
+
+Run both before submitting a PR. CI will catch style issues, but it is better to fix them locally first.
+
+## Submitting Changes
+
+1. Open a GitHub Issue describing your proposed change, or link to a Discord thread where it was discussed. Wait for feedback before writing code.
+2. Fork the repo and create a branch from `main`.
+3. Keep changes focused and minimal. One PR per issue.
+4. Add or update tests if applicable.
+5. Run the test suite and linter before pushing.
+6. Open a pull request against `main`. Reference the issue number in the PR description.
+
+Expect a response from maintainers, but be patient -- this is an actively developed project and review may take some time.
+
+## AI-Generated Code
+
+If you use AI tools to write or assist with your code, you must:
+
+- **Fully review all AI-generated code yourself** before submitting. You are responsible for understanding and standing behind every line in your PR.
+- **Include the prompts used** in the PR description. This gives maintainers additional context for reviewing the code.
+
+Pull requests with unreviewed AI-generated code will be closed.
+
+## Contributing to Documentation
+
+The documentation site lives in the `docs/` directory and is a **separate Next.js application** built with [Fumadocs](https://fumadocs.dev). It uses **npm** (not Bun) as its package manager.
+
+### Docs Setup
+
+```bash
+cd docs
+npm install
+npm run dev
+```
+
+The docs dev server runs on `http://localhost:3000`.
+
+### Where Documentation Lives
+
+Documentation content is written in MDX and located in `docs/content/docs/`. The directory is organized into:
+
+- `(documentation)/` -- core documentation pages
+- `guide/` -- guides and tutorials
+- `api-reference/` -- API reference (partially auto-generated from OpenAPI)
+
+To add or edit a page, create or modify an `.mdx` file in the appropriate directory. Page metadata is defined via frontmatter at the top of each file. Navigation order is controlled by `meta.json` files in each directory.
+
+### Building the Docs
+
+```bash
+npm run build
+```
+
+This generates the OpenAPI and MCP reference pages before building the Next.js site. Make sure the build succeeds locally before submitting a docs PR.
+
+## Reporting Bugs
+
+Open a GitHub Issue with:
+
+- A clear title describing the problem.
+- Steps to reproduce the bug.
+- Expected behavior vs. actual behavior.
+- Your environment (runtime, database, adapter, bknd version).
+- Any relevant error messages or logs.
+
+## Getting Help
+
+- **Discord**: https://discord.com/invite/952SFk8Tb8
+- **FAQ / Search**: https://www.answeroverflow.com/c/1308395750564302952
+- **GitHub Issues**: https://github.com/bknd-io/bknd/issues
+
+## Contributors
+
+Thank you to everyone who has contributed to bknd.
+
+<a href="https://github.com/bknd-io/bknd/graphs/contributors">
+  <img src="https://contrib.rocks/image?repo=bknd-io/bknd" />
+</a>
+
+Made with [contrib.rocks](https://contrib.rocks).
+
+## Maintainers
+
+- **Dennis** ([@dswbx](https://github.com/dswbx)) -- Creator and maintainer of bknd
+- **Cameron Pak** ([@cameronapak](https://github.com/cameronapak)) -- Maintainer of bknd docs

README.md

@@ -165,3 +165,19 @@ npx bknd run
 ```bash
 npm install bknd
 ```
+
+## Contributing
+
+We welcome contributions! Please read our [CONTRIBUTING.md](CONTRIBUTING.md) before getting started. It covers dev setup, project structure, testing, code style, and how to submit changes.
+
+Before writing code, please open a GitHub Issue or start a conversation in [Discord](https://discord.com/invite/952SFk8Tb8) so we can align on the approach.
+
+## Contributors
+
+Thank you to everyone who has contributed to bknd.
+
+<a href="https://github.com/bknd-io/bknd/graphs/contributors">
+  <img src="https://contrib.rocks/image?repo=bknd-io/bknd" />
+</a>
+
+Made with [contrib.rocks](https://contrib.rocks).