Azure Container Apps Express: The Agent-First Platform You've Been Waiting For

I've been running AI workloads on Azure Container Apps for over a year. Every time I spin up a new agent backend, the ritual is the same: create an environment, configure networking, set scaling rules, wire up health probes, then deploy the actual container. For a prototype agent that might live for a week, that's too much ceremony for what you get. ACA Express, which hit public preview in May 2026, kills most of that ceremony. And a separate but related announcement, Docker Compose for Agents, brings MCP gateways and model serving to standard ACA environments. They solve different problems and run on different infrastructure, but together they cover the full spectrum of agent deployment on Azure. Let me break down both. ACA Express: What It Actually Is Express is a new environment tier within Azure Container Apps. You bring a container image. Express handles provisioning, HTTPS, scaling (including scale-from-zero with subsecond cold starts), and resource allocation. No environment to manually provision through the portal. No networking to configure. No scaling rules to write. Under the hood, Express is built on ACA Sandboxes, a platform primitive that uses prewarmed pools to deliver that subsecond startup. This isn't the standard ACA cold-start experience with a fresh coat of paint. It's a different architecture. The tradeoffs are real. Express is HTTP workloads only, consumption CPU only. No GPU. No VNet integration. No Dapr. No service discovery between apps. No managed identity at runtime. No health probes. If you need any of those, standard ACA environments are still there. But for stateless HTTP agent backends, Express is dramatically faster to deploy and cheaper to run. Here's what it takes to get a container running: # Create an express environment az containerapp env create \ --name my-express-env \ --resource-group rg-my-agents \ --environment-mode express \ --logs-destination none # Deploy your app az containerapp create \ --name my-agent-api \ --resource