Pub/Sub overview

Crusoe AI Platform Pub/Sub is a fully managed, high-throughput publish/subscribe messaging service. It lets microservices, AI agents, and background workers communicate asynchronously without direct dependencies or waiting for immediate responses.

Core architecture

Pub/Sub relies on three main components:

• Topics: Named channels where publisher applications send messages.
• Subscriptions: Durable message queues or streams attached to topics. Each subscription receives its own copy of published messages and tracks its own position.
• Publishers and Consumers: Applications that send messages to topics (publishers) or retrieve messages from subscriptions (consumers).

Messaging models

Pub/Sub supports two delivery mechanisms:

• Pull Delivery: Your consumer requests waiting messages over HTTP, processes them, and acknowledges completion to remove them from the queue.
• Push Delivery: Pub/Sub automatically POSTs messages as CloudEvents to an HTTP endpoint in your project. If delivery fails, Pub/Sub retries automatically with exponential backoff and can route unprocessable messages to a dead-letter topic.

Key use cases

Use Pub/Sub whenever you need to:

• Decouple microservices: Keep publishers operating smoothly even when consumers are offline or processing slow tasks.
• Fan out events: Send a single event from one publisher to multiple independent subscriber services.
• Buffer workload spikes: Queue rapid bursts of incoming tasks so worker fleets can drain them at a steady pace.
• Trigger serverless functions: Automatically invoke HTTP services or functions whenever new events arrive.

Multi-tenant project isolation

Pub/Sub enforces complete project-level isolation. Topics, subscriptions, storage quotas, and credentials live entirely within your project scope:

• Default Storage Quota: Each project receives an allocated storage budget (1 GiB by default) for retained messages.
• Secure Boundaries: Topics and messages in one project cannot be accessed or viewed by other projects.
• Flexible Management: Configure topics and subscriptions using the Crusoe Console, platformctl CLI, or REST API.

Delivery guarantees

• At-Least-Once Delivery: Every published message is guaranteed to be delivered at least once to each active subscription. Design your consumers to handle duplicate messages harmlessly (idempotency).
• Message Ordering: Ordering can be configured per subscription (such as per-key ordering with key-shared subscriptions).

Cloud platform comparison

Feature	Crusoe AI Platform Pub/Sub	GCP Pub/Sub	AWS SNS + SQS	Azure Service Bus
Primary Model	Topics + Subscriptions	Topics + Subscriptions	SNS Topics + SQS Queues	Service Bus Topics + Subscriptions
Delivery Modes	Pull & HTTP Push	Pull & Push	SQS Polling / HTTP Endpoint	Pull & Push
Dead-Letter Handling	Managed Dead-Letter Topics	Dead-Letter Topics	Dead-Letter Queues	Dead-Letter Sub-queues
Protocols	HTTP REST & Native Wire Protocol	HTTP REST & gRPC	HTTP REST	AMQP & HTTP

API Endpoint

Pub/Sub is available on the public API at https://api.codyhill.dev. See the API Overview for details on base URLs and authentication.

Next steps

• Quickstart — Create a topic, publish a message, and consume it in minutes.
• Topics and subscriptions — Explore retention settings, quota allocation, and subscription types.
• Publish and consume — Detailed guide on API, CLI, Console usage, and delivery semantics.
• Pub/Sub Guide — Comprehensive single-page operational reference.