example

Workflow Engine Examples

This directory demonstrates various approaches for building applications with the Workflow Engine.

Workflow-Native Module Approach (Recommended)

All application components are configured using workflow-native module types. This is the simplest and most consistent approach.

Examples:

• simple-workflow-config.yaml - Basic HTTP server with routing
• api-server-config.yaml - REST API with custom handlers
• event-processor-config.yaml - Simple event processing
• realtime-messaging-modular-config.yaml - Real-time messaging with EventBus bridge
• api-gateway-config.yaml - API gateway with reverse proxy
• api-gateway-modular-config.yaml - API gateway with reverse proxy (alternate config)

Benefits:

• Easy YAML-based configuration with inline config blocks
• Built-in workflow routing system
• Great for rapid prototyping and production use
• Simple JSON response handlers

Modular Framework Modules (Legacy Support)

A few CrisisTextLine/modular framework modules are still supported but may be replaced by workflow-native equivalents in the future:

• scheduler.modular - CrisisTextLine/modular scheduler for cron-based job execution
• cache.modular - CrisisTextLine/modular caching module
• database.modular - CrisisTextLine/modular database module
• reverseproxy - CrisisTextLine/modular reverse proxy (not deprecated)

Examples:

• scheduled-jobs-modular-config.yaml - Advanced job scheduling with cron

Available Module Types

HTTP

• http.server - HTTP server that listens on a network address
• http.router - Routes HTTP requests to handlers
• http.handler - Handles HTTP requests and produces responses
• http.proxy / reverseproxy - Reverse proxy
• http.simple_proxy - Simple prefix-based reverse proxy
• static.fileserver - Serves static files with optional SPA fallback
• http.middleware.auth - Authentication middleware
• http.middleware.logging - Request logging middleware
• http.middleware.ratelimit - Rate limiting middleware
• http.middleware.cors - CORS headers middleware
• http.middleware.requestid - Request ID middleware
• http.middleware.securityheaders - Security headers middleware

API

• api.query - CQRS query handler
• api.command - CQRS command handler
• api.handler - REST API handler
• api.gateway - API gateway with routing, rate limiting, CORS, auth

Messaging

• messaging.broker - In-memory message broker
• messaging.broker.eventbus - EventBus bridge for pub/sub
• messaging.handler - Message handlers
• messaging.nats - NATS broker
• messaging.kafka - Kafka broker

State Machine

• statemachine.engine - State machine engine
• state.tracker - State tracking
• state.connector - State machine connector

Storage & Database

• storage.sqlite - SQLite storage
• storage.local - Local filesystem storage
• storage.s3 - S3 storage
• storage.gcs - GCS storage
• database.workflow - SQL database for workflow state
• persistence.store - Persistence store

Observability

• metrics.collector - Prometheus-compatible metrics
• health.checker - Health check endpoints
• log.collector - Log collection
• observability.otel - OpenTelemetry tracing

Feature Flags

• featureflag.service - Feature flag management with generic or LaunchDarkly provider
• step.feature_flag - Pipeline step to evaluate a feature flag
• step.ff_gate - Pipeline step combining flag evaluation with conditional routing

Other

• auth.jwt - JWT authentication
• auth.user-store - User store
• data.transformer - Data transformation
• webhook.sender - Webhook sending
• notification.slack - Slack notifications
• dynamic.component - Yaegi hot-reload components
• processing.step - Processing steps
• secrets.vault - HashiCorp Vault secrets
• secrets.aws - AWS Secrets Manager
• openapi.generator - OpenAPI spec generation
• openapi.consumer - OpenAPI spec consumption
• workflow.registry - Workflow registry

Legacy Examples

The following examples demonstrate various workflow patterns:

State Machine & Event Processing

• state-machine-workflow.yaml - E-commerce order processing states
• event-driven-workflow.yaml - Complex event pattern detection
• event-processor-config.yaml - Basic event processing

Integration & APIs

• integration-workflow.yaml - Third-party service integration
• sms-chat-config.yaml - SMS-based messaging workflow

Scheduling & Jobs

• advanced-scheduler-workflow.yaml - Complex scheduling scenarios
• scheduled-jobs-config.yaml - Recurring task management
• data-pipeline-config.yaml - Data processing workflows

Feature Flags

• feature-flag-workflow.yaml - Feature flag evaluation and gating in pipelines

Patterns & Examples

• multi-workflow-config.yaml - Multiple parallel workflows
• dependency-injection-example.yaml - Service injection patterns
• trigger-workflow-example.yaml - Event trigger demonstrations

Running Examples

Option 1: Specify configuration file

go run main.go -config <configuration-file>.yaml

Option 2: Interactive selection menu

go run main.go

This displays a numbered list of available configurations.