objectstack-platform

name	objectstack-platform
description	Bootstrap, configure, extend, and operate ObjectStack runtimes. Covers project setup (`defineStack`, drivers, adapters, scaffolding), plugin and service development (PluginContext, DI, kernel hooks like `kernel:ready`), and operations (CLI commands, migrations, deployment, test harnesses via LiteKernel). Use when the user is writing `objectstack.config.ts`, building a plugin or driver, wiring a framework adapter, running `os` CLI commands, or planning deployment. Do not use for data schema design (see objectstack-data) or query patterns (see objectstack-query); data lifecycle hooks (beforeInsert / afterUpdate) belong in objectstack-data — only kernel / service-level events live here.
license	Apache-2.0
compatibility	Requires @objectstack/spec 16.x and @objectstack/core 16.x (Zod v4 schemas), Node 18+
metadata	{"author":"objectstack-ai","version":"1.2","domain":"platform","tags":"project, defineStack, driver, adapter, plugin, kernel, service, DI, lifecycle, cli, deploy, ops"}

Platform — ObjectStack Bootstrap & Plugin System

Expert instructions for two related concerns:

1. Project setup — scaffolding new projects, writing objectstack.config.ts, picking drivers and adapters, the runtime boot sequence (the original "quickstart" skill).
2. Plugin development — building plugins, registering services, wiring kernel hook / event handlers, working with ObjectKernel vs LiteKernel (the original "plugin" skill).

Both areas share the same defineStack() / kernel surface, which is why they live in one skill.

---

When to Use This Skill

• Creating a new ObjectStack project from scratch.
• Choosing the right project template (blank, todo, compliance, content, contracts, procurement).
• Writing or modifying objectstack.config.ts (defineStack() config).
• Selecting a database driver (Memory, SQL, MongoDB).
• Integrating with a web framework (Hono via @objectstack/hono / @objectstack/plugin-hono-server).
• Understanding the runtime boot sequence and plugin loading order.
• Setting up multi-app composition with composeStacks().
• Answering "how do I get started?" questions.

---

Decision Tree: Choosing a Template

What are you building?
│
├── Starting from scratch / learning the platform?
│   └── ✅ blank (default)
│       • Bundled with create-objectstack — works offline
│       • One example object, in-memory driver, Hono server
│
├── A small task app to study end-to-end patterns?
│   └── ✅ todo
│
└── A domain starter with richer metadata?
    └── ✅ compliance | content | contracts | procurement
        • Fetched remotely from the objectstack-ai/templates repo

Scaffolding Command

# Interactive — prompts for name and template
npx create-objectstack

# Direct — skip prompts (blank is the default template)
npx create-objectstack my-app --template todo

Templates: blank (default, bundled) | todo | compliance | content | contracts | procurement (all except blank are fetched remotely from objectstack-ai/templates)

---

Project Structure Conventions

Every ObjectStack project follows this directory structure:

my-app/
├── objectstack.config.ts    # ← THE entry point — defineStack()
├── package.json
├── tsconfig.json
└── src/
    ├── objects/              # Business object definitions
    │   ├── task.object.ts    # → exports a single object
    │   └── index.ts          # → barrel: export * from './task.object'
    ├── views/                # Optional: UI view definitions
    │   ├── task.view.ts
    │   └── index.ts
    ├── apps/                 # Optional: app definitions (nav, pages)
    │   ├── main.app.ts
    │   └── index.ts
    ├── flows/                # Optional: automation flows
    │   ├── task.flow.ts
    │   └── index.ts
    ├── actions/              # Optional: action definitions
    │   ├── task.action.ts
    │   └── index.ts
    ├── dashboards/           # Optional: dashboards
    ├── reports/              # Optional: reports
    ├── i18n/                 # Optional: translation bundles
    └── handlers/             # Optional: runtime hook handlers

Naming Conventions

Concept	Convention	Example
File names	{name}.{type}.ts	task.object.ts, main.app.ts
Machine names	snake_case	project_task, first_name
Config keys	camelCase	maxLength, defaultValue
Barrel exports	Object.values(imported)	objects: Object.values(objects)

---

CRM Blueprint (Reference Implementation)

When scaffolding a production-style metadata app, align with this CRM-style layout:

Blueprint Area	CRM Reference	What to Reuse
Stack assembly	objectstack.config.ts	Single defineStack() root aggregating all metadata collections
By-type directories	src/{objects,views,pages,actions,flows,...}	Domain-per-folder layout with barrel exports
Typed aggregates	src/*/index.ts	Export allFlows / allAgents / allSkills typed arrays
Runtime capabilities	requires: ['ai','automation','analytics','auth','ui','approvals','sharing']	Declare opt-in capabilities explicitly
Security assembly	src/profiles/* + src/sharing/*	Compose permissions and sharingRules in stack root
Localization assembly	src/translations/* + i18n	Keep per-locale files and central bundle registration

Use this as the default template for “metadata application” requests before simplifying to a blank-style minimal stack.

---

defineStack() — The Core Configuration

objectstack.config.ts is the single entry point for every project. It calls defineStack() to declare all metadata.

Minimal Example

import { defineStack } from '@objectstack/spec';
import { Field } from '@objectstack/spec/data';

export default defineStack({
  manifest: {
    id: 'com.example.todo',
    version: '1.0.0',
    type: 'app',
    name: 'Todo Manager',
  },
  objects: [
    {
      name: 'task',
      label: 'Task',
      fields: {
        title:    Field.text({ required: true }),
        status:   Field.select({ options: [
          { label: 'Open', value: 'open' },
          { label: 'Done', value: 'done' },
        ], defaultValue: 'open' }),
        due_date: Field.date(),
      },
    },
  ],
});

Full Configuration Reference

defineStack() accepts an ObjectStackDefinitionInput. Each top-level key holds a collection of one metadata kind — manifest, objects, objectExtensions, views, apps, pages, dashboards, reports, datasets, actions, themes, flows, jobs, emailTemplates, docs, books, positions, permissions, capabilities, sharingRules, apis, webhooks, api, agents, tools, skills, hooks, functions, mappings, analyticsCubes, connectors, data (seed), datasources, datasourceMapping, translations, i18n, plugins, devPlugins, requires, tiers.

There is deliberately no top-level workflows or approvals collection: an approval is authored as a flow with Approval nodes (ADR-0019), and record state machines are a state_machine validation rule on each object (ADR-0020). Unknown keys are silently stripped by strict parsing — a phantom key like roles: or policies: is a no-op, not an error.

For the exact Zod shape — including which keys are optional and what types the collection items take — read node_modules/@objectstack/spec/src/stack.zod.ts (ObjectStackDefinitionSchema; the input type is ObjectStackDefinitionInput). Each collection's item shape lives in its own domain folder (data/object.zod.ts, ui/view.zod.ts, …).

Map Format (Key → Name)

All named collections support map format where the key becomes the name field:

export default defineStack({
  // Array format (traditional)
  objects: [
    { name: 'task', fields: { title: Field.text() } },
  ],

  // Map format (key becomes name) — preferred for readability
  objects: {
    task: { fields: { title: Field.text() } },
    project: { fields: { name: Field.text() } },
  },
});

Barrel Import Pattern

Use barrel exports to keep config clean:

// src/objects/index.ts
export { default as task } from './task.object';
export { default as project } from './project.object';

// objectstack.config.ts
import * as objects from './src/objects';
import * as apps from './src/apps';
import * as views from './src/views';
import * as flows from './src/flows';

export default defineStack({
  manifest: { id: 'com.example.pm', namespace: 'pm', version: '1.0.0', type: 'app', name: 'PM' },
  objects: Object.values(objects),
  apps: Object.values(apps),
  views: Object.values(views),
  flows: Object.values(flows),
});

Strict Validation

defineStack() validates by default (strict: true):

1. Zod schemas — field names, types, enums
2. Cross-references — views/actions/flows reference defined objects
3. Seed data — dataset objects exist in the definition

To disable (advanced — e.g., objects provided by another plugin):

export default defineStack({ ... }, { strict: false });

Compile Artifact and Runtime Metadata Boundary

ObjectStack runtime metadata must come from source files during local development or from a compiled artifact. Do not configure a project runtime to read or write metadata through its business database.

objectstack compile
# -> dist/objectstack.json

OS_ARTIFACT_PATH=./dist/objectstack.json objectstack dev

Runtime rule of thumb:

Context	Metadata source	Database role
Local dev	TS files or dist/objectstack.json	Business rows only
Production runtime	Artifact API response	Business rows only
Control plane	Published JSON in metadata storage	Project revisions, history, overlays

When generating objectstack.config.ts, keep object names short and snake_case; never set tableName, and do not add sys_metadata objects to a project runtime manifest.

---

Manifest Reference

Every stack needs a manifest to identify itself in the ecosystem:

manifest: {
  id: 'com.example.crm',        // Reverse domain unique ID
  version: '1.0.0',             // Semver
  type: 'app',                  // app | plugin | driver | module | ...
  name: 'Acme CRM',             // Human-readable display name
  description: 'CRM system',    // Optional description
}

Object naming: The object name is the canonical identifier and equals the physical table name. Embed any domain prefix directly in the name (e.g. name: 'crm_account'); the object-level namespace field is deprecated and ignored by the runtime.

manifest.namespace (ADR-0048): Optional, but enforced once set. When a package declares manifest.namespace: 'crm', every object.name must start with crm_ or defineStack errors (validateNamespacePrefix in @objectstack/spec); the legacy <ns>__<short> double-underscore form is rejected, and sys_-prefixed names are platform-reserved and exempt. The namespace is also a package-ownership key — installing two packages that both claim crm fails with NamespaceConflictError (downgrade to a warning with OS_METADATA_COLLISION=warn). os lint additionally emits a non-fatal naming/namespace-prefix warning for bare-named UI/automation items (app, page, dashboard, flow, action, report, dataset) when a namespace is set.

---

Driver Selection Guide

Drivers are the storage layer. Pick based on your environment:

Driver	Package	Best For	Notes
Memory	@objectstack/driver-memory	Dev, testing, prototyping	InMemoryDriver — data lost on restart
SQL	@objectstack/driver-sql	Production (PostgreSQL, MySQL, SQLite)	SqlDriver — Knex.js under the hood (pg / mysql / better-sqlite3 clients)
MongoDB	@objectstack/driver-mongodb	Production (document store)	MongoDBDriver
SQLite WASM	@objectstack/driver-sqlite-wasm	Browser / WebContainer	SqliteWasmDriver — in-process, no server
Turso	@objectstack/driver-turso	Edge, serverless, multi-tenant	Cloud / EE only — ships with the ObjectStack cloud / enterprise distribution, not the open framework. The open-core CLI recognizes libsql:// URLs but fails loudly (UnsupportedDriverError)

Usage Pattern

import { DriverPlugin } from '@objectstack/runtime';

// Development (in-memory, zero config)
import { InMemoryDriver } from '@objectstack/driver-memory';
new DriverPlugin(new InMemoryDriver())

// Production (SQLite)
import { SqlDriver } from '@objectstack/driver-sql';
new DriverPlugin(new SqlDriver({
  client: 'better-sqlite3',
  connection: { filename: './data/app.db' },
  useNullAsDefault: true,
}))

// Production (PostgreSQL)
new DriverPlugin(new SqlDriver({
  client: 'pg',
  connection: process.env.DATABASE_URL,
}))

---

Adapter Selection Guide

The HTTP layer is Hono-based. Two packages exist:

Package	Export	Use When
@objectstack/hono	createHonoApp({ kernel, prefix })	You own the server: embed ObjectStack routes in your own Hono app / deploy target.
@objectstack/plugin-hono-server	HonoServerPlugin	ObjectStack owns the server: a kernel plugin that hosts the Hono app and opens the listening socket (this is what os dev / os serve register).

There are no @objectstack/adapter-* packages (no adapter-express / -fastify / -nextjs / -nuxt / -nestjs / -sveltekit). To integrate another framework, mount the Hono app (a web-standard fetch handler) or call the dispatcher yourself.

Usage Pattern (Hono)

import { createHonoApp } from '@objectstack/hono';

const app = createHonoApp({
  kernel,                    // ObjectKernel instance
  prefix: '/api',            // API route prefix (default: '/api')
});

export default app;          // Deploy to Cloudflare Workers, Deno, Bun, Node

Architecture

createHonoApp follows this architecture:

1. Accept a kernel (ObjectKernel) instance
2. Create an HttpDispatcher internally
3. Mount explicit routes for auth, GraphQL, storage, discovery
4. Delegate everything else to the dispatcher

This means new routes added to HttpDispatcher work automatically without adapter code changes.

---

Runtime Boot Sequence

Understanding how ObjectStack starts helps debug and customize:

objectstack.config.ts
  └── defineStack({ manifest, objects, views, ... })
        │
        ▼
CLI: `os serve` / `os dev`
  1. Load .env files (NODE_ENV-based)
  2. Dynamic import of config file
  3. Create Runtime + ObjectKernel
  4. Auto-detect and register plugins (in this order):
     ├── ObjectQLPlugin (if objects defined)
     ├── DriverPlugin (memory in dev, SQL in prod)
     ├── AppPlugin (loads the defineStack bundle)
     ├── I18nServicePlugin (if translations/i18n defined)
     ├── HonoServerPlugin (registered BEFORE AuthPlugin — the server must
     │     exist for plugins that mount routes during init/start)
     ├── AuthPlugin
     ├── Split platform-app plugins (ADR-0048, optional/best-effort, after AuthPlugin):
     │     @objectstack/setup → createSetupAppPlugin   (first-run wizard)
     │     @objectstack/account → createAccountAppPlugin
     │     (@objectstack/studio is intentionally NOT default-loaded — the
     │      Console, mounted at /_console/ by `--ui`, ships its own Studio
     │      surface at /_console/studio/…)
     ├── RESTPlugin (auto-generated API)
     ├── DispatcherPlugin
     └── AIServicePlugin (cloud / EE only — reverse-mounted by a cloud host; absent in the open framework per cloud ADR-0025)
  5. Runtime.start() → init + start all plugins
  6. Server listens on the resolved port (see "Ports & networking" in Part 3)

Port resolution (both os dev and os start → os serve): --port flag › $OS_PORT › $PORT › 3000. On a conflict the behaviour is mode-dependent — dev hops to the next free port, production fails loudly. See Ports & networking.

Plugin Loading Order Matters

Plugins initialize in registration order. Key dependencies:

Plugin	Depends On	Reason
ObjectQLPlugin	(none)	Core data engine, should load first
DriverPlugin	(none)	Registers driver service
AppPlugin	ObjectQLPlugin	Registers objects/metadata with engine
AuthPlugin	ObjectQLPlugin	Needs user/session objects
RESTPlugin	ObjectQLPlugin, AppPlugin	Generates routes from registered objects
AIServicePlugin	ObjectQLPlugin, AppPlugin	Needs metadata for tool generation. Cloud / EE only — @objectstack/service-ai moved to cloud (cloud ADR-0025); the open edition has no in-UI AI plugin and uses @objectstack/mcp (BYO-AI)

Programmatic Bootstrap (Without CLI)

import { Runtime, DriverPlugin, AppPlugin } from '@objectstack/runtime';
import { ObjectQLPlugin } from '@objectstack/objectql';
import { InMemoryDriver } from '@objectstack/driver-memory';
import appConfig from './objectstack.config';

const runtime = new Runtime();
runtime.use(new ObjectQLPlugin());
runtime.use(new DriverPlugin(new InMemoryDriver()));
runtime.use(new AppPlugin(appConfig));
await runtime.start();

const kernel = runtime.getKernel();
// kernel is now ready — use it with an adapter

---

Multi-App Composition

Use composeStacks() to merge multiple apps into one runtime:

import { composeStacks, defineStack } from '@objectstack/spec';
import CrmApp from './apps/crm/objectstack.config';
import TodoApp from './apps/todo/objectstack.config';

const combined = composeStacks([CrmApp, TodoApp], {
  objectConflict: 'error',   // Throw on duplicate object names
  manifest: 'last',          // Use last stack's manifest
});

export default combined;

Conflict Strategies

Strategy	Behavior
'error' (default)	Throw if two stacks define the same object name
'override'	Last stack wins — later definition replaces earlier
'merge'	Shallow-merge objects with same name (later fields win)

Host Pattern (Plugins as AppPlugin)

For a hosting environment where each app runs isolated:

import { Runtime, DriverPlugin, AppPlugin } from '@objectstack/runtime';
import { ObjectQLPlugin } from '@objectstack/objectql';
import { AuthPlugin } from '@objectstack/plugin-auth';

export default defineStack({
  manifest: { id: 'platform-host', type: 'app', version: '1.0.0', name: 'Platform' },
  plugins: [
    new ObjectQLPlugin(),
    new DriverPlugin(new SqlDriver({ ... })),
    new AuthPlugin({ secret: process.env.AUTH_SECRET }),
    new AppPlugin(CrmApp),     // contributes objects: crm_account, crm_lead, ...
    new AppPlugin(TodoApp),    // contributes objects: task, ...
  ],
});

Each app registers its objects by their canonical name. Object names are globally unique and equal the physical table name — use them directly in queries, hooks, formulas, and REST URLs.

---

Seed Data

Declarative data loading for bootstrapping, demos, and testing:

export default defineStack({
  // ... objects, apps, etc.
  data: [
    {
      object: 'task',
      mode: 'upsert',              // 'upsert' | 'insert' | 'update' | 'ignore' | 'replace'
      externalId: 'subject',       // Idempotency key for upsert matching
      records: [
        { subject: 'Learn ObjectStack', status: 'open', priority: 'high' },
        { subject: 'Build first app', status: 'open', priority: 'medium' },
      ],
    },
  ],
});

Mode	Behavior
upsert (default)	Insert or update based on externalId match
insert	Always insert (fails on duplicate)
update	Only update found records; ignore new ones
ignore	Insert if not exists, skip otherwise
replace	Drop and re-insert all records

---

CLI Commands

Daily commands are covered in Part 3 — Operations below (jump there). High-level cheat sheet for the bootstrap loop:

npx create-objectstack my-app
cd my-app && npm install
os dev --ui          # dev server + Console at /_console/ (auto-hops port if taken)
os validate          # metadata cross-reference checks
os compile           # produce dist/ artifact
os migrate plan      # preview metadata↔DB schema drift (additive sync never alters existing columns)
os migrate apply     # reconcile DB to metadata (loosening only; --allow-destructive for drops/tightenings)
PORT=8080 os start   # production — pin the port explicitly (see Ports & networking)

---

Complete Working Example

A minimal but complete project from scratch:

package.json (mirrors the blank template):

{
  "name": "my-todo-app",
  "type": "module",
  "scripts": {
    "dev": "objectstack dev",
    "start": "objectstack start",
    "build": "objectstack build",
    "validate": "objectstack validate"
  },
  "dependencies": {
    "@objectstack/spec": "^16.0.0-rc.1",
    "@objectstack/runtime": "^16.0.0-rc.1",
    "@objectstack/driver-memory": "^16.0.0-rc.1",
    "@objectstack/plugin-hono-server": "^16.0.0-rc.1"
  },
  "devDependencies": {
    "@objectstack/cli": "^16.0.0-rc.1",
    "typescript": "^6.0.0"
  }
}

src/objects/task.object.ts:

import { Field } from '@objectstack/spec/data';

export default {
  name: 'task',
  label: 'Task',
  fields: {
    title:       Field.text({ label: 'Title', required: true }),
    description: Field.textarea({ label: 'Description' }),
    status:      Field.select({
      label: 'Status',
      options: [
        { label: 'Open', value: 'open' },
        { label: 'In Progress', value: 'in_progress' },
        { label: 'Done', value: 'done' },
      ],
      defaultValue: 'open',
    }),
    priority: Field.select({
      label: 'Priority',
      options: [
        { label: 'Low', value: 'low' },
        { label: 'Medium', value: 'medium' },
        { label: 'High', value: 'high' },
      ],
      defaultValue: 'medium',
    }),
    due_date: Field.date({ label: 'Due Date' }),
  },
  indexes: [
    { fields: ['status'] },
    { fields: ['due_date'] },
  ],
};

src/objects/index.ts:

export { default as task } from './task.object';

objectstack.config.ts:

import { defineStack } from '@objectstack/spec';
import * as objects from './src/objects';

export default defineStack({
  manifest: {
    id: 'com.example.todo',
    version: '1.0.0',
    type: 'app',
    name: 'Todo Manager',
  },
  objects: Object.values(objects),
});

# Run it
os dev --ui
# → Server at http://localhost:3000 (default port; dev auto-hops if taken)
# → REST API at http://localhost:3000/api
# → Console at http://localhost:3000/_console/

---

---

Part 2 — Plugin Development & Kernel Extension

When to Use This Skill

• You are creating a new plugin (driver, server, service, app feature)
• You need to register or consume services via the DI container
• You are using the hook/event system for inter-plugin communication
• You need to choose between ObjectKernel and LiteKernel
• You are debugging plugin loading order or dependency resolution
• You need to configure graceful shutdown, timeouts, or health checks
• You are implementing service factories with lifecycle management

---

Quick Reference — Detailed Rules

For comprehensive documentation with incorrect/correct examples:

• Plugin Lifecycle — 3-phase lifecycle (init/start/destroy), execution order, complete examples
• Service Registry — DI container, factories, lifecycles (singleton/transient/scoped), core fallbacks
• Hooks & Events — Kernel hooks & events reference (record-level lifecycle hooks → objectstack-data)

---

ObjectKernel vs LiteKernel

Feature	ObjectKernel	LiteKernel
Use case	Production servers, full applications	Serverless, edge, unit tests
Package	@objectstack/core	@objectstack/core
Plugin loading	Async with validation & metadata	Synchronous use()
Service factories	Singleton / Transient / Scoped	Direct instances only
Health monitoring	Built-in per-plugin health checks	Not available
Graceful shutdown	Timeout + rollback on failure	Basic destroy phase
Dependency resolution	Topological sort + circular detection (throws)	Topological sort (throws on cycles)
Core fallbacks	Auto-injects in-memory fallbacks	Not available
Config validation	Zod schema validation per plugin	Not available

Decision Guide

What environment are you targeting?
│
├── Production server / full application?
│   └── ✅ ObjectKernel
│       • Full DI with factories and scopes
│       • Health monitoring and auto-recovery
│       • Graceful shutdown with timeout
│       • Startup failure rollback
│
├── Serverless / edge (Cloudflare Workers, Deno Deploy)?
│   └── ✅ LiteKernel
│       • Minimal memory footprint
│       • Fast cold start
│       • No background health checks
│
└── Unit tests (vitest)?
    └── ✅ LiteKernel
        • Simple setup, fast teardown
        • No system requirement validation
        • No shutdown signal handlers

ObjectKernel Configuration

import { ObjectKernel } from '@objectstack/core';

const kernel = new ObjectKernel({
  logger: {
    level: 'info',           // 'debug' | 'info' | 'warn' | 'error' | 'fatal'
    format: 'json',          // 'json' | 'text' | 'pretty'
  },
  defaultStartupTimeout: 30000,   // Per plugin (ms)
  gracefulShutdown: true,         // Register SIGINT/SIGTERM handlers
  shutdownTimeout: 60000,         // Total shutdown timeout (ms)
  rollbackOnFailure: true,        // Rollback all plugins if one fails
  skipSystemValidation: false,    // Skip system checks (useful for tests)
});

LiteKernel Configuration

import { LiteKernel } from '@objectstack/core';

const kernel = new LiteKernel({
  logger: { level: 'warn' },
});

---

Plugin Interface — Quick Overview

import type { Plugin, PluginContext } from '@objectstack/core';

export interface Plugin {
  name: string;               // Unique identifier (reverse domain recommended)
  version?: string;           // Semantic version
  type?: string;              // 'standard' | 'ui' | 'driver' | 'server' | 'app'
  dependencies?: string[];    // Plugins that must init before this one

  // Phase 1: Register services
  init(ctx: PluginContext): Promise<void> | void;

  // Phase 2: Execute business logic (optional)
  start?(ctx: PluginContext): Promise<void> | void;

  // Phase 3: Cleanup (optional)
  destroy?(): Promise<void> | void;
}

See rules/plugin-lifecycle.md for complete examples.

---

PluginContext API

Service Registry

// Register a service (in init phase)
ctx.registerService('my-service', myServiceInstance);

// Get a service (in start phase)
const db = ctx.getService<IDataEngine>('objectql');

// Replace a service
ctx.replaceService('cache', new InstrumentedCache(existingCache));

// Get all services
const allServices: Map<string, any> = ctx.getServices();

See rules/service-registry.md for factories and lifecycles.

Hook / Event System

// Register a kernel hook handler
ctx.hook('kernel:ready', async () => {
  ctx.logger.info('System is ready!');
});

// React to a metadata hot-reload / publish
ctx.hook('metadata:reloaded', async (payload?: { changed?: string[] }) => {
  ctx.logger.info('Metadata reloaded', { changed: payload?.changed });
});

// Trigger a custom hook
await ctx.trigger('my-plugin:initialized', { version: '1.0.0' });

Built-in kernel events: kernel:ready, kernel:bootstrapped, kernel:listening, kernel:shutdown, app:seeded, metadata:reloaded, external.schema.drift.

⚠️ There are no data:* kernel hooks. Record-level lifecycle logic (beforeInsert / afterUpdate / …) runs on the ObjectQL engine, not the kernel event bus — author it via the hooks: collection or ql.on('beforeInsert', 'task', async (ctx) => { … }) (see objectstack-data). Because ctx.hook() accepts any string, a handler registered for 'data:beforeInsert' will register successfully and then silently never fire. Kernel hooks are for platform lifecycle only.

See rules/plugin-hooks-events.md for the kernel event list, payloads, and patterns.

Logger

ctx.logger.debug('Detailed trace info', { key: 'value' });
ctx.logger.info('Plugin initialized');
ctx.logger.warn('Cache miss rate high', { rate: 0.45 });
ctx.logger.error('Connection failed', error);

Kernel Access

const kernel = ctx.getKernel();
const isRunning = kernel.isRunning();
const state = kernel.getState(); // 'idle' | 'initializing' | 'running' | 'stopping' | 'stopped'

---

Complete Plugin Example

// src/plugins/audit.ts
import type { Plugin, PluginContext } from '@objectstack/core';

interface AuditEntry {
  timestamp: string;
  event: string;
  detail?: Record<string, unknown>;
}

class AuditService {
  private log: AuditEntry[] = [];

  record(event: string, detail?: Record<string, unknown>) {
    this.log.push({ timestamp: new Date().toISOString(), event, detail });
  }

  getLog(): AuditEntry[] {
    return [...this.log];
  }
}

const AuditPlugin: Plugin = {
  name: 'com.example.audit',
  version: '1.0.0',
  type: 'plugin',

  async init(ctx: PluginContext) {
    // Phase 1: Register service and kernel hooks
    const auditService = new AuditService();
    ctx.registerService('audit', auditService);

    ctx.hook('kernel:ready', async () => {
      auditService.record('kernel:ready');
    });

    ctx.hook('metadata:reloaded', async (payload?: { changed?: string[] }) => {
      auditService.record('metadata:reloaded', { changed: payload?.changed });
    });

    ctx.logger.info('Audit plugin initialized');
  },

  async start(ctx: PluginContext) {
    // Phase 2: Log that audit is active
    ctx.logger.info('Audit logging active');
  },

  async destroy() {
    // Phase 3: Cleanup
  },
};

export default AuditPlugin;

To audit record writes (who inserted/updated which record), register engine lifecycle hooks instead — e.g. ctx.getService('objectql').on('afterInsert', 'task', async (hookCtx) => …) in start(), or the declarative hooks: collection. See objectstack-data for the engine hook contract.

---

Using Plugins

import { ObjectKernel } from '@objectstack/core';
import { ObjectQLPlugin } from '@objectstack/objectql';
import { DriverPlugin } from '@objectstack/runtime';
import { InMemoryDriver } from '@objectstack/driver-memory';
import AuditPlugin from './plugins/audit';

const kernel = new ObjectKernel();
await kernel.use(new ObjectQLPlugin());
await kernel.use(new DriverPlugin(new InMemoryDriver()));
await kernel.use(AuditPlugin);
await kernel.bootstrap();

// Services are now available
const audit = kernel.getService<AuditService>('audit');

---

Testing Plugins

import { describe, it, expect } from 'vitest';
import { LiteKernel } from '@objectstack/core';
import type { PluginContext } from '@objectstack/core';
import AuditPlugin from './audit';

describe('AuditPlugin', () => {
  it('records kernel lifecycle events', async () => {
    const kernel = new LiteKernel({ logger: { level: 'silent' } });
    kernel.use(AuditPlugin);

    // `kernel.context` is protected — to fire events in a test, capture a
    // PluginContext from a probe plugin instead.
    let probe!: PluginContext;
    kernel.use({ name: 'test.probe', init(ctx) { probe = ctx; } });

    await kernel.bootstrap();   // fires kernel:ready → recorded

    // Simulate a metadata hot-reload announcement
    await probe.trigger('metadata:reloaded', { changed: ['object/task'] });

    const audit = kernel.getService<{ getLog(): { event: string }[] }>('audit');
    const events = audit.getLog().map((e) => e.event);
    expect(events).toContain('kernel:ready');
    expect(events).toContain('metadata:reloaded');

    await kernel.shutdown();
  });
});

---

Well-Known Plugin Names & Services

Plugin Name	Service Key	Package
com.objectstack.engine.objectql	objectql (also data)	@objectstack/objectql
com.objectstack.driver.*	driver.{name}	@objectstack/driver-*
com.objectstack.auth	auth	@objectstack/plugin-auth
com.objectstack.rest.api	— (registers no service)	@objectstack/rest
com.objectstack.metadata	metadata	@objectstack/metadata
com.objectstack.service.realtime	realtime	@objectstack/service-realtime
com.objectstack.service.cache	cache	@objectstack/service-cache
com.objectstack.server.hono	—	@objectstack/plugin-hono-server → HonoServerPlugin
com.objectstack.setup	—	@objectstack/setup → createSetupAppPlugin (ADR-0048 one-app pkg)
com.objectstack.studio	—	@objectstack/studio → createStudioAppPlugin
com.objectstack.account	—	@objectstack/account → createAccountAppPlugin
com.objectstack.cloud.connection	—	@objectstack/cloud-connection → createCloudConnectionPlugin

---

MetadataPlugin Runtime Boundary

MetadataPlugin is the IMetadataService provider for the ObjectStack runtime, but runtime metadata is read-only and artifact/file backed:

• Do not register sys_metadata or sys_metadata_history from an ObjectStack runtime plugin. Those persistence tables belong to the control plane. (Exception, #1826: an isolated project kernel may opt into sys_metadata hydration from its own DB — the general boundary otherwise stands.)
• Do not call MetadataManager.setDataEngine() automatically from MetadataPlugin.start(). Project databases must contain business rows only.
• Use artifactSource: { mode: 'local-file', path: './dist/objectstack.json' } for local artifact boot; production should use the Artifact API loader once wired.
• DatabaseLoader, setDatabaseDriver(), and setDataEngine() remain valid for control-plane services that explicitly own metadata revisions, history, or overlays.

import { MetadataPlugin } from '@objectstack/metadata';

await kernel.use(new MetadataPlugin({
  watch: false,
  artifactSource: { mode: 'local-file', path: './dist/objectstack.json' },
}));

---

Health Monitoring (ObjectKernel Only)

const MyPlugin: Plugin & { healthCheck(): Promise<PluginHealthStatus> } = {
  name: 'com.example.db',
  version: '1.0.0',

  async init(ctx) { /* ... */ },

  async healthCheck() {
    try {
      await this.pool.query('SELECT 1');
      return { healthy: true, message: 'Database connected' };
    } catch (err) {
      return { healthy: false, message: 'Database unreachable', details: { error: err.message } };
    }
  },
};

// Check health
const health = await kernel.checkPluginHealth('com.example.db');
const allHealth = await kernel.checkAllPluginsHealth();

// Get startup metrics
const metrics = kernel.getPluginMetrics();
// Map<string, number> — plugin name → startup duration in ms

---

Feature Flags

Feature flags are a protocol shape, not a config key. FeatureFlagSchema (from @objectstack/spec/kernel) defines the flag document; in the protocol it appears only on the runtime capabilities descriptor (ObjectStackCapabilities.system.features) that a platform serves for introspection. There is no featureFlags: / features: key on defineStack — strict parsing silently strips unknown keys, so such config would be a no-op.

import { FeatureFlag } from '@objectstack/spec/kernel';
import type { ObjectStackCapabilities } from '@objectstack/spec';

// FeatureFlag.create() gives you a compile-checked flag value:
const aiCopilot = FeatureFlag.create({
  name: 'experimental_ai_copilot',
  label: 'AI Copilot',
  enabled: true,
  strategy: 'percentage',
  conditions: { percentage: 25 },   // 25% of users
  environment: 'prod',              // 'dev' | 'staging' | 'prod' | 'all' (default 'all')
});

// Where flags live in the protocol — the runtime capabilities descriptor:
type SystemFeatures = NonNullable<ObjectStackCapabilities['system']['features']>;
const features: SystemFeatures = [
  aiCopilot,
  {
    name: 'beta_kanban_view',
    label: 'Kanban View',
    enabled: true,
    strategy: 'group',
    conditions: { groups: ['beta_testers'] },
    environment: 'all',
  },
];

Strategies: boolean | percentage | user_list | group | custom

Looking for live, resolvable toggles today? Those are different surfaces, not FeatureFlagSchema: the feature_flags settings manifest (@objectstack/service-settings, env-overridable via OS_FEATURE_FLAGS_*) and auth capability gates (requiresFeature → PUBLIC_AUTH_FEATURES).

---

---

Part 3 — Operations: CLI, Testing, Deployment

The @objectstack/cli package ships an os binary (alias: objectstack). Every project gets the same command surface — npm install does not need to be re-run when commands are added.

Daily-loop commands

Command	What it does
os init	Scaffold a new project (alternative to npx create-objectstack)
os dev	Start the dev server with hot metadata reload. --seed-admin (default on for plain os dev) seeds a loginable dev admin in-process via the runtime (env vars OS_SEED_ADMIN*) on an empty DB only — idempotent, never overwrites an existing account (default [e-mail] / admin123; override with --admin-email / --admin-password; disable with --no-seed-admin). --fresh = ephemeral clean OS_HOME/DB, implies --seed-admin. The seeded admin is promoted to platform admin, so Setup/Studio work on first login.
os dev --ui	Also mount the bundled Console portal at /_console/ (there is no separate os studio command)
os validate	Validate objectstack.config.ts — Zod protocol schema, CEL/predicate validation (record.<field> existence), and widget-binding integrity. Same gates as os build, no artifact emitted. See Verify your work.
os lint	Style/convention lint on metadata files
os info	Print a metadata summary of the config (objects, apps, and other collections; --json)
os doctor	Diagnose common setup issues

Build & runtime

Command	What it does
os build	Compile TS metadata, bundle, and produce dist/
os compile	Compile to portable JSON artifact (for runtime hydration)
os serve	Serve a compiled stack in production mode
os start	Quick-start a server: auto-compiles objectstack.config.ts when no artifact is present, and falls back to an empty kernel with the Console + marketplace when there is no config at all. It does not validate env or apply migrations — run os validate / os migrate apply yourself
os generate <kind>	Scaffold an object / view / flow / agent from a template

Verify your work

ObjectStack metadata mistakes fail silently at runtime, not at edit time: a bare field ref in a predicate (done instead of record.done) evaluates to null and silently hides an action/validation on every record (#2183/#2185); a dangling dashboard widget binding renders an empty chart (ADR-0021). Both are caught at author time by one command:

os validate     # Zod schema + CEL predicates + widget bindings — no artifact
# or
os build        # the same three gates, plus emits dist/objectstack.json

os validate and os build run the same structural + semantic gates:

1. Zod protocol schema — the stack conforms to @objectstack/spec.
2. CEL / predicate validation (ADR-0032) — every visible / disabled / requiredWhen / validation rule / flow condition / sharing rule is parsed for CEL syntax and checked that each record.<field> reference exists on the target object. A bare field (missing record.) fails here.
3. Widget-binding integrity (ADR-0021) — every dashboard widget's dataset / dimensions / values resolves to a declared dataset/field.

Both exit non-zero with a located, corrective message; os build additionally emits the artifact. Use os validate as the fast inner-loop check after editing metadata and os build when you need dist/. In a scaffolded project these are npm run validate / npm run build.

Rule of thumb: never report a metadata change as done until os validate passes. (os lint is a separate style/convention pass — naming, labels, namespace prefixes — and does not replace os validate.)

Ports & networking

Port resolution is the same for os dev and os start (both spawn os serve):

--port <n>  ›  $OS_PORT  ›  $PORT  ›  3000   (default)

Conflict behaviour is mode-dependent — this is deliberate:

Mode	If the resolved port is busy
Dev (os dev, or NODE_ENV=development)	Auto-hops to the next free port (up to +100) so several example apps run side-by-side. The startup banner shows the actual bound port.
Production (os start)	Fails loudly and exits 1. It never silently drifts — a shifted port breaks reverse-proxy upstreams, better-auth callback URLs, and CORS trusted-origins as opaque 403/502s.

Production guidance:

• Pin the port explicitly — PORT=8080 os start (or --port 8080). Don't rely on the 3000 default; it collides easily on shared hosts.
• Keep these in sync when you change the port (mismatch ⇒ better-auth Invalid origin 403 / CORS failures):
  • reverse-proxy upstream (nginx/caddy)
  • OS_AUTH_URL / better-auth baseURL + callbackURL
  • OS_TRUSTED_ORIGINS (CORS allow-list)
  • the app's hostname
• Recommended topology: terminate TLS on a reverse proxy (:443) and let the app listen on an internal high port (e.g. 8080) fixed via PORT.

Data & migrations

Command	What it does
os data create / get / query / update / delete	Record-level CRUD against a running server (there is no os data seed / export / import — seed data in the data: collection loads automatically at boot)
os diff	Compare two ObjectStack config files and detect breaking changes
os meta register / os meta resync	Register (create/update) metadata on a target server / re-sync it (there is no os meta apply)
os migrate plan / os migrate apply	Dry-run / apply physical-DB drift reconciliation from metadata (forward-only — no batch rollback; os rollback was removed)

Environments & deploy

Command	What it does
os login / logout / whoami	Auth against the ObjectStack cloud control plane
os environments list / create / switch	Manage cloud environments (prod/staging/dev)
os register	Register the local stack as a deployable target
os cloud login / logout / whoami	Cloud auth subcommands (these three only — there are no os cloud logs/metrics/status)
os package publish [dist/objectstack.json] [--env … --install --visibility org]	Upload the compiled artifact as a versioned package to the cloud catalog (ADR-0008 P3)
os package install <manifest-id │ ./dist/objectstack.json> [--version │ --runtime http://localhost:3000]	Install a package into a running runtime via its install-local endpoint. Catalog mode (by manifest id) or air-gapped local-artifact mode. Auths with the target runtime's session (--email/--password or OS_RUNTIME_EMAIL/OS_RUNTIME_PASSWORD), not the cloud login

Cloud connection & marketplace (@objectstack/cloud-connection, ADR-0008/0009). The open runtime-side cloud client. Its plugins — CloudConnectionPlugin/createCloudConnectionPlugin, MarketplaceProxyPlugin, MarketplaceInstallLocalPlugin, RuntimeConfigPlugin — expose the install-local endpoint that os package install targets, ship the Installed Apps page and marketplace Setup nav as plugin metadata, and maintain LocalManifestSource (a local desired-state ledger) plus runtime-identity bind v2 (environment-less self-hosted binding).

Testing pattern

Use LiteKernel for unit / integration tests — it skips the cloud bits and plugin discovery, so tests run in milliseconds. Assemble the same plugins the CLI would auto-register (use() is synchronous and chainable):

import { describe, it, expect } from 'vitest';
import { LiteKernel } from '@objectstack/core';
import { ObjectQLPlugin } from '@objectstack/objectql';
import { DriverPlugin, AppPlugin } from '@objectstack/runtime';
import { InMemoryDriver } from '@objectstack/driver-memory';
import stack from '../objectstack.config';

describe('stack boot', () => {
  it('registers the task object', async () => {
    const kernel = new LiteKernel({ logger: { level: 'silent' } });
    kernel
      .use(new ObjectQLPlugin())
      .use(new DriverPlugin(new InMemoryDriver()))
      .use(new AppPlugin(stack));
    await kernel.bootstrap();

    const ql = kernel.getService<any>('objectql');
    // query / mutate through the engine — see objectstack-query for the API
    expect(ql).toBeDefined();

    await kernel.shutdown();
  });
});

• Seed in tests: declare fixtures in the stack's data: collection — they load at boot. See objectstack-data for env-scoped fixtures (env: ['test']).
• Reset between tests: create a fresh LiteKernel per test — with the in-memory driver a full bootstrap is cheap, and there is no reset().
• HTTP-level tests: mount createHonoApp({ kernel }) from @objectstack/hono and drive it with app.request(...) / fetch.

Deployment targets

Target	Driver	HTTP layer	Notes
Node.js server	driver-sql (pg / mysql / better-sqlite3)	plugin-hono-server / @objectstack/hono	Default — works anywhere Node runs
Edge (Cloudflare Workers, Vercel Edge)	driver-turso (cloud / EE only)	@objectstack/hono	Cold-start friendly; LiteKernel only
Serverless (Lambda, Vercel functions)	driver-sql (pg with pooler) / driver-mongodb	@objectstack/hono	Mind cold-start: prefer LiteKernel
Browser / WebContainer	driver-sqlite-wasm	none (in-process)	Playground, demos
Docker / Kubernetes	any	any	Use os start as the entrypoint; pin PORT and EXPOSE it (see Ports & networking)

Health & observability

• Health endpoints: the HTTP dispatcher exposes GET /health and GET /ready under the API prefix (see "Health Monitoring" earlier in this skill).
• Logs: plugins log via ctx.logger. Logger config is a kernel construction option, not a defineStack key: new ObjectKernel({ logger: { level: 'info', format: 'json' } }).
• Metrics: use the kernel's built-ins — kernel.getPluginMetrics() (per-plugin startup durations) and await kernel.checkAllPluginsHealth(). There is no metrics service and no @objectstack/plugin-prometheus.

Common ops pitfalls

Symptom	Likely cause
os dev hangs at "Loading metadata…"	Circular import in objectstack.config.ts — run os validate
os start exits with "Port N is already in use"	Intended: production never auto-shifts ports. Free the port or set PORT=<n> — see Ports & networking
better-auth Invalid origin 403 after a port/host change	Port or hostname out of sync with OS_AUTH_URL / OS_TRUSTED_ORIGINS — see Ports & networking
Migrations apply locally but not in cloud	env scoping on the dataset excludes the target environment
Adapter 404s on auto-generated routes	enable.apiEnabled: false on the object, or missing os build
LiteKernel test passes, ObjectKernel boot fails	Test missed a plugin the CLI auto-registers — compare your test's use() list against the os dev boot log
Hot reload misses new objects	Barrel src/objects/index.ts not re-exporting — check the file
Login works but Setup / Studio missing	The logged-in user isn't a platform admin. Setup/Studio are gated by setup.access / studio.access on admin_full_access, auto-granted only to the first registered human (bootstrapPlatformAdmin). The usr_system seed identity is skipped, so it can't steal the grant. Either sign up first (--seed-admin/--fresh does this) or check sys_user_permission_set for a cross-tenant (organization_id = NULL) admin_full_access link on your user. Don't edit nav code first.

---

References

See references/_index.md for the full list of Zod schemas (with one-line descriptions) — pointers into node_modules/@objectstack/spec/src/. Always Read the source for exact field shapes; do not rely on memory of property names.