sdk_features.md

SDK Features Overview (PHP)

Core Features

AI Agent Framework

• AgentBase class for building voice AI agents as HTTP microservices
• Prompt Object Model (POM) for structured prompt construction
• SWAIG (SignalWire AI Gateway) tool framework with native media stack access
• Dynamic per-request configuration via callbacks
• Multi-agent server for hosting multiple agents on one port

SWML Document Generation

• Full SWML (SignalWire Markup Language) document creation and validation
• Schema validation against the official SWML schema
• Dynamic verb creation for call control
• Pre-answer and post-AI verb injection

SWAIG Function System

• Define tools with JSON schema parameter validation
• FunctionResult class with 20+ action methods (connect, SMS, record, hold, etc.)
• Method chaining for fluent action composition
• Post-processing mode for AI-first response delivery
• History management with replaceInHistory()

DataMap Tools

• Declarative tools that execute on SignalWire's servers
• Webhook integration for REST API calls
• Expression-based pattern matching
• Variable expansion with dot notation and encoding functions
• No webhook infrastructure required

Contexts and Steps

• Multi-step conversation flows with named contexts
• Per-context system prompts and personas
• Step-to-step and context-to-context navigation
• Conversation history management (consolidate, full_reset)

Skills System

• Modular skill architecture with auto-discovery
• 17+ built-in skills (datetime, math, web_search, datasphere, etc.)
• Parameter-configurable skills
• Dependency validation
• Custom skill support via SkillBase extension

Prefab Agents

• InfoGathererAgent -- guided question flows for data collection
• SurveyAgent -- structured surveys with rating, yes/no, and open-ended questions
• ConciergeAgent -- multi-purpose reception agent
• ReceptionistAgent -- call routing and screening
• FAQBotAgent -- knowledge-base Q&A

Communication Features

REST Client

• Synchronous HTTP client for all SignalWire REST APIs
• Namespaced sub-objects: fabric, calling, phoneNumbers, video, datasphere, registry, etc.
• Full Fabric API: AI agents, SWML scripts, subscribers, call flows, conference rooms, SIP gateways
• Call control: dial, play, record, collect, detect, AI, transcribe, tap, stream
• Phone number management, 10DLC, MFA, logs
• Array returns for zero-overhead data access

RELAY Client

• Real-time call control over WebSocket (Blade protocol, JSON-RPC 2.0)
• Synchronous blocking API
• Auto-reconnect with exponential backoff
• All calling methods: play, record, collect, connect, detect, fax, tap, stream, AI, conferencing, queues
• SMS/MMS messaging: send, receive, track delivery
• Action objects with wait(), stop(), pause(), resume()
• Typed event classes
• Dynamic context subscription

Infrastructure Features

Security

• Automatic basic authentication with auto-generated credentials
• SSL/TLS support (direct or via reverse proxy)
• SWAIG function authentication
• Metadata tokens for scoped data access
• CORS and security headers

Configuration

• JSON configuration files with environment variable substitution
• Multi-location config file discovery
• Docker-friendly environment variable support
• Zero-config mode with sensible defaults

Logging

• Structured logging via SignalWire\Logging\Logger
• Configurable log levels (debug, info, warn, error)
• Debug webhook support for remote debugging

Deployment

• Built-in HTTP server for development and production
• Docker support
• Cloud function adapter (SignalWire\Serverless\Adapter)
• Multi-agent server for microservice architecture
• Reverse proxy compatible

Language and Speech

• Multi-language support with per-language voice selection
• Speech recognition hints for domain vocabulary
• Custom pronunciation mappings
• Barge-in confidence control
• End-of-speech and attention timeouts

Session Management

• Global data for AI context persistence
• Metadata for function-scoped state
• Summary callbacks for post-call processing
• Session lifecycle hooks