@bernierllc/nevar-engine

Central orchestration engine for the Nevar rules engine suite. Provides createNevar(), emit(), preview(), pipeline orchestration, rule CRUD with validation, and registration delegation.

Installation

npm install @bernierllc/nevar-engine

Usage

import { createNevar } from '@bernierllc/nevar-engine';

const engine = createNevar({
  storage: myStorageAdapter,
  failureMode: 'fail-fast',
});

// Register operators, triggers, actions, and context providers
engine.registerOperator('equals', {
  label: 'Equals',
  category: 'comparison',
  evaluate: (a, b) => a === b,
  schema: {},
});

engine.registerTrigger('user.created', {
  payloadSchema: {},
  description: 'Fired when a new user is created',
});

engine.registerAction('send-email', {
  label: 'Send Email',
  category: 'notification',
  configSchema: {},
  canDefer: false,
  handler: async (config, context) => {
    // send email logic
    return { sent: true };
  },
});

// Emit a trigger
const result = await engine.emit('user.created', { email: '[email protected]' });

// Preview without executing actions
const preview = await engine.preview('user.created', { email: '[email protected]' });

// Rule CRUD (validates before writing to storage)
const rule = await engine.createRule({ /* ... */ });
await engine.updateRule(rule.id, { name: 'Updated Rule' });
await engine.deleteRule(rule.id);

API

createNevar(config: NevarConfig): Nevar

Factory function to create a new engine instance.

Registration

• registerOperator(name, definition) - Register a condition operator
• registerTrigger(key, definition) - Register a trigger type
• registerAction(actionType, definition) - Register an action handler
• registerContextProvider(prefix, provider) - Register a context enrichment provider

Core

• emit(triggerKey, payload, groupId?) - Emit a trigger and execute matching rules
• preview(triggerKey, payload, groupId?) - Preview without executing actions

Rule CRUD

• createRule(rule) - Create with validation
• updateRule(id, patch) - Update with conditional re-validation
• deleteRule(id) - Delete a rule

Discovery

• operators.list() / operators.get(name)
• triggers.list() / triggers.get(key)
• actions.list() / actions.get(type)
• loops.list() / loops.inspect(id) / loops.kill(id) / loops.pause(id) / loops.resume(id)

Integration Documentation

Logger Integration

This package integrates with @bernierllc/logger for structured logging. The engine logs pipeline execution stages, rule evaluation results, action outcomes, and error chains. Use logger's context-level switching to control verbosity per trigger or rule at runtime.

NeverHub Integration

This package integrates with @bernierllc/neverhub-adapter. When NeverHub is available, the engine registers itself for discovery and monitoring, exposing operator/trigger/action registrations and pipeline health metrics. Graceful degradation is supported when NeverHub is not present -- all core engine functionality works regardless.

License

Copyright (c) 2025 Bernier LLC. All rights reserved.