Knative vs Restate

Knative is open-source Kubernetes middleware for building, deploying, and managing serverless workloads. Knative Serving handles stateless HTTP services, including deployment, routing, and automatic scaling. Services can scale from zero when idle and rise again with incoming traffic. Serving also supports blue-green deployments, canary releases, and traffic splitting between revisions. Knative Eventing routes asynchronous events through CloudEvents over HTTP. Knative Functions provides a framework for packaging stateless functions as containers. Installation can use a local quickstart or a production setup on an existing Kubernetes cluster with YAML or the Knative Operator. The project runs on Kubernetes across cloud providers and on-premises environments, with Linux, macOS, and Windows listed for installation. Integrations include Istio, Contour, Gateway API, Kafka, RabbitMQ, and NATS. The open-source plan is free, with self-managed Kubernetes deployment.

Restate is a durable execution runtime for building resilient services, workflows, and AI agents. It records progress during execution and resumes after failures without discarding completed work. Its building blocks include durable functions, workflows, Virtual Objects, queues, durable RPC, timers, signals, and flow control. The interface exposes execution journals and controls to cancel, kill, restart, or pause executions. Restate runs as a self-hosted single binary, managed Restate Cloud, or BYOC in a customer cloud account. Listed SDKs include TypeScript, Python, Java, Go, Kotlin, Rust, and Ruby. Integrations include Vercel AI SDK, OpenAI Agents SDK, Google ADK, Google Gemini, Pydantic AI, and LangChain. The homepage reports under 10ms P99 latency overhead under load for durable actions. The Free plan is free for 50k durable actions monthly with no credit card. Restate Cloud starts at $75 a month.