Since: 0.2.5

The PromptBuilder provides unified directive management for AI requests with priority-based ordering and agent-specific targeting. It replaces the previous scattered filter-based directive application with a structured builder pattern.

Overview

Prior to v0.2.5, AI directives were applied through separate datamachine_global_directives and datamachine_agent_directives filters, creating inconsistent ordering and maintenance overhead. The PromptBuilder centralizes this functionality into a single, priority-ordered system.

Architecture

┌─────────────────────────────────────────────────────┐
│              PromptBuilder Pattern                 │
│  (/inc/Engine/AI/PromptBuilder.php)                │
│                                                    │
│  ┌──────────────────┐      ┌──────────────────┐   │
│  │ Directive        │      │ Priority-Based   │   │
│  │ Registration     │      │ Ordering         │   │
│  │ (addDirective)   │      │ (usort by pri)   │   │
│  └──────────────────┘      └──────────────────┘   │
│                                                    │
│  ┌──────────────────┐      ┌──────────────────┐   │
│  │ Agent Type       │      │ Sequential       │   │
│  │ Targeting        │      │ Application      │   │
│  │ ('all', 'pipeline│      │ (build method)   │   │
│  │  'chat')         │      └──────────────────┘   │
│  └──────────────────┘                             │
└─────────────────────────────────────────────────────┘

Key Features

• Priority-Based Ordering: Lower priority numbers applied first (10=core, 20=global, 30=pipeline, 40=context, 50=site)
• Agent Targeting: Directives can target ‘all’ agents or specific types (‘pipeline’, ‘chat’)
• Unified Registration: Single datamachine_directives filter replaces multiple filter types
• Structured Builder Pattern: Fluent interface for directive configuration and request building

Usage

Basic Usage

use DataMachineEngineAIPromptBuilder;

// Create builder instance
$builder = new PromptBuilder();

// Set initial messages and tools
$builder->setMessages($messages)
        ->setTools($tools);

// Add directives with priorities
$builder->addDirective(MyDirective::class, 20, ['all'])
        ->addDirective(PipelineDirective::class, 30, ['pipeline']);

// Build final request
$request = $builder->build('pipeline', 'openai', $payload);

Directive Registration

Directives are registered via the datamachine_directives filter:

add_filter('datamachine_directives', function($directives) {
    $directives[] = [
        'class' => GlobalSystemPromptDirective::class,
        'priority' => 20,
        'agent_types' => ['all']
    ];

    return $directives;
});

Priority Guidelines

Priority Order (lower = applied first):

• 10-19: Core agent identity and foundational instructions
• 20-29: Global system prompts and universal behavior
• 30-39: Agent-specific system prompts and context
• 40-49: Workflow and execution context directives
• 50+: Environmental and site-specific directives

Current Directive Implementations

Global Directives (apply to all agents)

• GlobalSystemPromptDirective – User-configured global AI behavior (priority 20)
• SiteContextDirective – WordPress site context injection (priority 50)

Pipeline Directives

• PipelineCoreDirective – Foundational pipeline agent identity (priority 10)
• PipelineSystemPromptDirective – User-defined pipeline prompts (priority 30)

Chat Directives

• ChatAgentDirective – Chat agent identity and capabilities (priority 10)

Integration with RequestBuilder

The PromptBuilder is integrated into the RequestBuilder for seamless directive application:

// In RequestBuilder.php
$promptBuilder = new PromptBuilder();
$promptBuilder->setMessages($messages)
              ->setTools($structured_tools);

// Apply directives via PromptBuilder
$request = $promptBuilder->build($agent_type, $provider, $context);

Migration from Legacy System

Before (v0.2.4 and earlier)

// Separate filters with inconsistent ordering
add_filter('datamachine_global_directives', 'apply_global_directive', 10, 5); // LEGACY - use datamachine_directives instead
add_filter('datamachine_agent_directives', 'apply_agent_directive', 10, 5); // LEGACY - use datamachine_directives with agent_types to target 'pipeline'/'chat'

After (v0.2.5+)

// Unified registration with explicit priorities
add_filter('datamachine_directives', function($directives) {
    $directives[] = [
        'class' => MyDirective::class,
        'priority' => 25,
        'agent_types' => ['all']
    ];
    return $directives;
});

Benefits

• Consistent Ordering: Priority-based system ensures predictable directive application
• Agent Targeting: Fine-grained control over which directives apply to which agents
• Maintainability: Single registration point reduces filter complexity
• Extensibility: Easy to add new directives with proper ordering
• Debugging: Clear priority logging helps troubleshoot directive conflicts

Related Components

• RequestBuilder Pattern – Uses PromptBuilder for directive application
• Universal Engine Architecture – Overall AI infrastructure
• AI Conversation Loop – Multi-turn conversation execution