name: "Event-Driven Application"
id: event-driven-app
description: "Asynchronous system with message brokers, event sourcing, CQRS, and saga patterns"
estimated_duration: "6-14 weeks"
icon: "bolt"

# Default technology recommendations
defaults:
  broker: kafka
  language: typescript
  framework: nestjs
  event_store: kafka
  read_database: postgresql
  schema_registry: confluent
  streaming: kafka_streams

# Alternative technology stacks
alternatives:
  broker:
    - id: kafka
      name: "Apache Kafka"
      description: "High-throughput distributed streaming"
    - id: rabbitmq
      name: "RabbitMQ"
      description: "Feature-rich message broker"
    - id: aws_sqs_sns
      name: "AWS SQS/SNS"
      description: "Managed messaging service"
    - id: redis_streams
      name: "Redis Streams"
      description: "Lightweight, low-latency"
    - id: azure_service_bus
      name: "Azure Service Bus"
      description: "Enterprise messaging"

  language:
    - id: typescript
      name: "TypeScript/Node.js"
      description: "Async-first, good Kafka libraries"
    - id: java
      name: "Java (Spring Cloud Stream)"
      description: "Mature ecosystem, Kafka Streams"
    - id: go
      name: "Go"
      description: "High performance consumers"
    - id: python
      name: "Python"
      description: "Data processing, Faust library"

  framework:
    - id: nestjs
      name: "NestJS"
      description: "Built-in microservices transport"
    - id: spring_cloud_stream
      name: "Spring Cloud Stream"
      description: "Declarative event binding"
    - id: fastapi
      name: "FastAPI"
      description: "Async Python framework"
    - id: axon
      name: "Axon Framework"
      description: "Event sourcing & CQRS framework"

  event_store:
    - id: kafka
      name: "Kafka (as event store)"
      description: "Log-based event storage"
    - id: eventstoredb
      name: "EventStoreDB"
      description: "Purpose-built event store"
    - id: postgres_eventide
      name: "PostgreSQL + Eventide"
      description: "SQL-based event store"
    - id: dynamodb
      name: "DynamoDB Streams"
      description: "Serverless event storage"

  streaming:
    - id: kafka_streams
      name: "Kafka Streams"
      description: "Native Kafka stream processing"
    - id: ksqldb
      name: "ksqlDB"
      description: "SQL for stream processing"
    - id: flink
      name: "Apache Flink"
      description: "Stateful stream processing"
    - id: spark_streaming
      name: "Spark Streaming"
      description: "Big data stream processing"

# Phases of development
phases:
  - id: discovery
    name: "Event Discovery"
    description: "Event storming, domain events identification, and aggregate design"
    order: 1
    checkpoint: true
    checkpoint_message: |
      Event discovery complete. Review:
      - Domain events catalog
      - Aggregate boundaries
      - Command/event flows
      - Event ownership

      Approve to proceed with architecture.

    steps:
      - id: event_storming
        name: "Event Storming"
        agent: researcher
        description: "Conduct event storming workshop"

      - id: domain_events
        name: "Domain Events"
        agent: architect
        description: "Catalog all domain events"

      - id: aggregates
        name: "Aggregate Design"
        agent: architect
        description: "Define aggregate boundaries"

      - id: command_flows
        name: "Command Flows"
        agent: architect
        description: "Map commands to events"

    outputs:
      - ".omgkit/generated/event-catalog.md"
      - ".omgkit/generated/aggregates.md"
      - ".omgkit/generated/command-flows.md"

  - id: architecture
    name: "Event Architecture"
    description: "Topic design, schemas, CQRS strategy, and saga patterns"
    order: 2
    checkpoint: true
    checkpoint_message: |
      Architecture design complete. Review:
      - Topic/queue design
      - Event schemas (Avro/JSON)
      - CQRS implementation plan
      - Saga patterns for transactions

      Approve to begin foundation.

    steps:
      - id: topic_design
        name: "Topic Design"
        agent: architect
        description: "Design topics, partitions, retention"

      - id: schema_design
        name: "Schema Design"
        agent: architect
        description: "Design event schemas with versioning"

      - id: cqrs_design
        name: "CQRS Design"
        agent: architect
        description: "Plan command/query separation"

      - id: saga_design
        name: "Saga Design"
        agent: architect
        description: "Design distributed transaction patterns"

    outputs:
      - ".omgkit/generated/topic-design.md"
      - ".omgkit/generated/event-schemas/"
      - ".omgkit/generated/cqrs-design.md"
      - ".omgkit/generated/saga-patterns.md"

  - id: foundation
    name: "Infrastructure Foundation"
    description: "Message broker, schema registry, and base configuration"
    order: 3
    checkpoint: false

    steps:
      - id: broker_setup
        name: "Broker Setup"
        agent: fullstack-developer
        description: "Set up Kafka/RabbitMQ"

      - id: schema_registry
        name: "Schema Registry"
        agent: fullstack-developer
        description: "Configure schema registry"

      - id: topic_creation
        name: "Topic Creation"
        agent: fullstack-developer
        description: "Create topics with configs"

      - id: dlq_setup
        name: "Dead Letter Queue"
        agent: fullstack-developer
        description: "Set up DLQ for failed messages"

      - id: shared_libs
        name: "Shared Libraries"
        agent: fullstack-developer
        description: "Event types, serialization"

    outputs:
      - "docker-compose.yml"
      - "schemas/"
      - "packages/events/"

  - id: producers
    name: "Event Producers"
    description: "Implement command handlers and event publishing"
    order: 4
    checkpoint: true
    checkpoint_message: |
      Producers implemented. Review:
      - Command handlers
      - Event publishing
      - Transactional outbox
      - Idempotency keys

      Approve to proceed with consumers.

    steps:
      - id: command_handlers
        name: "Command Handlers"
        agent: fullstack-developer
        description: "Implement command processing"

      - id: event_publishing
        name: "Event Publishing"
        agent: fullstack-developer
        description: "Implement event producers"

      - id: outbox_pattern
        name: "Transactional Outbox"
        agent: fullstack-developer
        description: "Implement outbox for reliability"

      - id: idempotency
        name: "Idempotency"
        agent: fullstack-developer
        description: "Add idempotency keys"

      - id: producer_tests
        name: "Producer Tests"
        agent: tester
        description: "Test event publishing"

    outputs:
      - "src/commands/"
      - "src/producers/"
      - "tests/producers/"

  - id: consumers
    name: "Event Consumers"
    description: "Event handlers, projections, and saga orchestrators"
    order: 5
    checkpoint: true
    checkpoint_message: |
      Consumers implemented. Review:
      - Event handlers
      - Projections (read models)
      - Saga orchestration
      - Error handling

      Approve to proceed with CQRS.

    steps:
      - id: event_handlers
        name: "Event Handlers"
        agent: fullstack-developer
        description: "Implement event consumers"

      - id: projections
        name: "Projections"
        agent: fullstack-developer
        description: "Build read model projections"

      - id: saga_orchestrators
        name: "Saga Orchestrators"
        agent: fullstack-developer
        description: "Implement saga patterns"

      - id: error_handling
        name: "Error Handling"
        agent: fullstack-developer
        description: "Retries, DLQ, compensation"

      - id: consumer_tests
        name: "Consumer Tests"
        agent: tester
        description: "Test event consumption"

    outputs:
      - "src/consumers/"
      - "src/projections/"
      - "src/sagas/"
      - "tests/consumers/"

  - id: cqrs
    name: "CQRS Implementation"
    description: "Query side APIs, read models, and eventual consistency"
    order: 6
    checkpoint: false

    steps:
      - id: read_models
        name: "Read Models"
        agent: fullstack-developer
        description: "Design optimized read models"

      - id: query_apis
        name: "Query APIs"
        agent: fullstack-developer
        description: "Implement query endpoints"

      - id: consistency_handling
        name: "Consistency Handling"
        agent: fullstack-developer
        description: "Handle eventual consistency UX"

      - id: cache_strategy
        name: "Cache Strategy"
        agent: fullstack-developer
        description: "Cache read models if needed"

    outputs:
      - "src/queries/"
      - "src/read-models/"

  - id: monitoring
    name: "Testing & Monitoring"
    description: "Event flow testing, consumer lag monitoring, and observability"
    order: 7
    checkpoint: true
    checkpoint_message: |
      Monitoring complete. Review:
      - Event flow tests
      - Consumer lag alerts
      - Schema evolution tests
      - Observability dashboards

      This is the final checkpoint.

    steps:
      - id: flow_tests
        name: "Event Flow Tests"
        agent: tester
        description: "Test complete event flows"

      - id: lag_monitoring
        name: "Lag Monitoring"
        agent: fullstack-developer
        description: "Monitor consumer lag"

      - id: schema_tests
        name: "Schema Evolution Tests"
        agent: tester
        description: "Test schema compatibility"

      - id: observability
        name: "Observability"
        agent: fullstack-developer
        description: "Dashboards for events"

      - id: replay_testing
        name: "Replay Testing"
        agent: tester
        description: "Test event replay scenarios"

    outputs:
      - "tests/flows/"
      - "monitoring/"
      - "docs/"

# Autonomy rules for this archetype
autonomy_rules:
  - pattern: "**/events/**"
    level: 3
    reason: "Event schemas are contracts"
  - pattern: "**/schemas/**"
    level: 3
    reason: "Schema changes affect all consumers"
  - pattern: "**/sagas/**"
    level: 3
    reason: "Saga logic is transaction-critical"
  - pattern: "**/projections/**"
    level: 2
    reason: "Read model changes need review"
  - pattern: "**/handlers/**"
    level: 2
    reason: "Event handling logic"
  - pattern: "**/consumers/**"
    level: 2
    reason: "Consumer configuration"
  - pattern: "kafka*.yaml"
    level: 3
    reason: "Broker configuration"
  - pattern: "**/dlq/**"
    level: 3
    reason: "Dead letter queue handling"
  - pattern: ".env*"
    level: 4
    reason: "Environment secrets"

# Quality gates
quality_gates:
  after_feature:
    - "npm test"
    - "npm run lint"
    - "schema compatibility check"
  before_checkpoint:
    - "all unit tests pass"
    - "event flow tests pass"
    - "no consumer lag issues"
  before_deploy:
    - "schema registry healthy"
    - "replay tests pass"
    - "monitoring configured"

# Event-driven specific discovery questions
discovery_additions:
  - category: "Events"
    questions:
      - "What are the main domain events?"
      - "Event sourcing needed or just messaging?"
      - "Event replay requirements?"
      - "Event retention period?"
      - "Schema evolution strategy?"

  - category: "Consistency"
    questions:
      - "Eventual consistency acceptable?"
      - "Need distributed transactions (sagas)?"
      - "Ordering requirements (strict or relaxed)?"
      - "Exactly-once or at-least-once semantics?"

  - category: "CQRS"
    questions:
      - "Separate read and write models?"
      - "Query performance requirements?"
      - "Real-time projections needed?"
      - "Historical query needs?"

  - category: "Infrastructure"
    questions:
      - "Message broker preference?"
      - "Expected message throughput?"
      - "Partition strategy?"
      - "Multi-region requirements?"

  - category: "Integration"
    questions:
      - "External systems to integrate?"
      - "Legacy system events?"
      - "Webhook requirements?"
      - "CDC (Change Data Capture) needs?"