FlowReactor Backlog

Real WebSocket server (RFC 6455) - Receives messages from app → emits to timeline - Can push messages to the app (from UI or scenario triggers) - Config: port, path - MessagePublished (from app), MessageDelivered (from server to app) events - Why: Real-time features (notifications, live updates) are common; hard to test without a server

Returns 429 Too Many Requests after N requests/window - Retry-After header on 429 responses - Config: requestsPerWindow, windowSeconds, bucketBy (global/ip/api-key-header) - FaultInjected events with fault="RateLimit" - Why: Rate limiting is a class of bug most developers never test properly; very common with external APIs

MongoDB wire protocol (port 27017) - In-memory per-collection document store - Supports: insert, find (basic), findOne, update, delete, createIndex, listCollections - QueryExecuted, ObjectStored, ObjectRetrieved events - Config: database name, initialCollections - Why: Second most common NoSQL store; developers need a local instance without Docker

AMQP protocol on port 5671 (ASB uses AMQP 1.0, not 0-9-1) - Queue + Topic/Subscription modes - DeadLetterQueue support (already modeled in existing fault system) - MessagePublished, MessageDelivered, MessageAcked, MessageDeadLettered events - Config: queueName/topicName, subscriptionName, lockDurationSeconds - Why: Large segment of .NET developers use Azure; filling the AWS/Azure parity gap

HTTP endpoint emulating SNS API (POST /?Action=Publish etc.) - Fan-out to subscribed nodes (SQS queues, HTTP webhooks) - Topic ARN routing - MessagePublished events per subscription - Config: topicArn, subscriptionProtocol (sqs/http) - Why: Common AWS pattern; SQS already exists so SNS→SQS fan-out is the obvious next step

Full RESP-style Kafka binary protocol (port 9092) - Producer publish → Consumer group delivery - Topic partitioning (simplified: all to partition 0) - Consumer group offset tracking - MessagePublished, MessageDelivered, MessageAcked events - Config: topicName, consumerGroup, partitions (1–16) - Why: Used by almost every modern distributed system; currently silently ignored at runtime