Async Flow Mapper

Overview

Identifies all asynchronous communication patterns in the codebase — message queues, event dispatching, webhooks, scheduled tasks, and background jobs. Documents the sync-to-async boundaries, message formats, consumer chains, and error handling strategies.

Detection Patterns

Message Queue Publishing

# RabbitMQ (php-amqplib, Symfony Messenger)
Grep: "AMQPMessage|AMQPChannel|AMQPConnection" --glob "**/*.php"
Grep: "basic_publish|queue_declare|exchange_declare" --glob "**/*.php"

# Symfony Messenger
Grep: "MessageBusInterface|->dispatch\\(" --glob "**/*.php"
Grep: "#\\[AsMessageHandler\\]" --glob "**/*.php"
Grep: "Envelope|Stamp" --glob "**/*.php"

# Laravel Queue
Grep: "implements ShouldQueue" --glob "**/*.php"
Grep: "dispatch\\(new|Queue::push" --glob "**/*.php"

# Redis queues
Grep: "Redis::.*push|->lpush|->rpush" --glob "**/*.php"
Grep: "Predis|PhpRedis|redis" --glob "**/*.php"

# Generic publish patterns
Grep: "->publish\\(|->enqueue\\(|->sendToQueue" --glob "**/*.php"

Event Dispatching

# Symfony EventDispatcher
Grep: "EventDispatcherInterface|->dispatch\\(" --glob "**/*.php"
Grep: "#\\[AsEventListener\\(" --glob "**/*.php"
Grep: "implements EventSubscriberInterface" --glob "**/*.php"

# Domain Events
Grep: "DomainEvent|->recordEvent|->raise" --glob "**/Domain/**/*.php"
Grep: "EventBus|DomainEventPublisher" --glob "**/*.php"

# Laravel Events
Grep: "event\\(new|Event::dispatch" --glob "**/*.php"
Grep: "class.*Listener" --glob "**/Listeners/**/*.php"

Webhooks

# Outgoing webhooks
Grep: "webhook|Webhook" --glob "**/*.php"
Grep: "->post\\(.*callback|->send.*notification" --glob "**/*.php"

# Incoming webhook handlers
Grep: "function.*webhook|#\\[Route.*webhook" --glob "**/*.php"

# Webhook retry/delivery tracking
Grep: "WebhookDelivery|delivery_attempts|retry_after" --glob "**/*.php"

Scheduled Tasks / Cron

# Symfony Scheduler
Grep: "#\\[AsCronTask\\]|#\\[AsPeriodicTask\\]" --glob "**/*.php"
Grep: "RecurringMessage|Schedule" --glob "**/*.php"

# Laravel Scheduler
Grep: "->command\\(|->call\\(|->job\\(" --glob "**/Console/Kernel.php"

# Custom schedulers
Grep: "cron|schedule|periodic|interval" --glob "config/**/*.{php,yaml,yml}"

Background Jobs

# Process forking
Grep: "pcntl_fork|proc_open|Process::" --glob "**/*.php"

# Async operations
Grep: "async|promise|Future|Deferred" --glob "**/*.php"

# Worker patterns
Grep: "class.*Worker|class.*Consumer|class.*Processor" --glob "**/*.php"
Grep: "function consume|function process|function work" --glob "**/*.php"

Analysis Process

Step 1: Map Sync-Async Boundaries

For each message/event dispatch found:

1. Read the publisher — what triggers the async operation
2. Read the message class — what data is sent
3. Find the consumer/handler — what processes the message
4. Check transport config — queue name, exchange, routing

Step 2: Trace Consumer Chains

Event Published → Handler 1 → may publish Event 2 → Handler 2 → ...

# Find what handlers dispatch
Grep: "->dispatch\\(|->publish\\(" --glob "**/Handler/**/*.php"
Grep: "->dispatch\\(|->publish\\(" --glob "**/Listener/**/*.php"

Step 3: Document Error Handling

# Retry configuration
Grep: "retry|RetryStrategy|maxRetries|max_retries" --glob "**/*.php"
Grep: "retry:" --glob "config/**/*.yaml"

# Dead letter queue
Grep: "dead_letter|failed_queue|DLQ" --glob "**/*.php"
Grep: "dead_letter" --glob "config/**/*.yaml"

# Error handling in consumers
Grep: "catch.*Exception|->reject|->nack" --glob "**/Handler/**/*.php"

Output Format

## Async Communication Map

### Overview

| Type | Count | Transport |
|------|-------|-----------|
| Queue Messages | 8 | RabbitMQ (Symfony Messenger) |
| Domain Events | 12 | In-process + async relay |
| Webhooks (outgoing) | 3 | HTTP POST |
| Scheduled Tasks | 5 | Symfony Scheduler |

### Sync-Async Boundaries

[Sync World] [Async World]

CreateOrderUseCase ├── save(order) └── dispatch(OrderCreated) ──→ Queue: "orders" ├── SendConfirmationEmail ├── ReserveInventory └── NotifyAnalytics

ProcessPayment └── dispatch(PaymentReceived)→ Queue: "payments" ├── UpdateOrderStatus └── SendReceipt

### Message Catalog

| Message | Publisher | Consumer(s) | Queue | Async |
|---------|-----------|-------------|-------|-------|
| OrderCreated | CreateOrderUseCase | EmailHandler, InventoryHandler | orders | Yes |
| PaymentReceived | PaymentService | OrderStatusHandler, ReceiptHandler | payments | Yes |
| UserRegistered | RegisterUseCase | WelcomeEmailHandler | users | Yes |
| DailyReport | Scheduler (02:00) | ReportGenerator | reports | Yes |

### Consumer Chains

OrderCreated └── InventoryHandler └── dispatches: InventoryReserved └── WarehouseHandler └── dispatches: PackingStarted

### Queue Configuration

| Queue | Exchange | Routing Key | Consumers | Prefetch |
|-------|----------|-------------|-----------|----------|
| orders | order_exchange | order.* | 3 | 10 |
| payments | payment_exchange | payment.# | 2 | 5 |
| notifications | notify_exchange | notify.email | 5 | 20 |

### Error Handling

| Message | Retry | Max Attempts | Dead Letter | Fallback |
|---------|-------|-------------|-------------|----------|
| OrderCreated | Exponential backoff | 3 | orders_dlq | Log + Alert |
| PaymentReceived | Fixed delay 5s | 5 | payments_dlq | Manual review |
| EmailNotification | Fixed delay 10s | 3 | None | Silent drop |

### Scheduled Tasks

| Schedule | Task | Description | Duration |
|----------|------|-------------|----------|
| 0 2 * * * | DailyReportCommand | Generate daily reports | ~5 min |
| */5 * * * * | HealthCheckCommand | Service health check | ~10 sec |
| 0 0 * * 0 | CleanupCommand | Remove expired data | ~15 min |

### Webhook Endpoints

| Direction | URL/Endpoint | Trigger | Payload |
|-----------|-------------|---------|---------|
| Outgoing | partner-api/notify | OrderShipped | {orderId, trackingNo} |
| Incoming | /webhooks/payment | Payment provider | {transactionId, status} |

Async Flow Quality Indicators

Indicator	Good	Warning
Message idempotency	Handlers are idempotent	No deduplication
Error handling	Retry + DLQ + alerting	Silent failure
Message format	Typed message classes	Array/JSON strings
Consumer isolation	Each handler does one thing	Handler chains in one
Monitoring	Queue depth metrics	No monitoring

Integration

This skill is used by:

• data-flow-analyst — documents async communication paths
• trace-request-lifecycle — identifies where sync becomes async
• explain-business-process — shows async steps in workflows