Google open-sources AX, a declarative control plane for running coding agents at scale

Google launched AX (agentexecutor.io, github.com/google/ax), an Apache-2.0 open-source control plane for running agentic workloads at scale. Agents are declared as YAML tasks (`ax apply`) with four primitives: sandboxed Tasks, auto-provisioned Workspaces (git repos, MCP servers, skills), network-allowlist Gateways, and centralized Model/secret config. It builds on Agent Substrate, which Google says enables very large numbers of concurrent agent sessions with sub-second resume of suspended tasks.